The Distribution of Thermal Neutron Flux into the Self-shielded Wall Equipped with a Medical Self-shielded PET Cyclotron

The Journal of the Korean Physical Society


Using the MDCT thick slab MinIP method for the follow-up of pulmonary emphysema

The purpose of this study was to evaluate the usefulness of thick slab minimum intensity projection (MinIP) as a follow-up method in patients with pulmonary emphysema. This method was used to determine the presence or absence of changes over time in the lung field based on multi-detector-row CT (MDCT) data. Among patients diagnosed with pulmonary emphysema who underwent 16-MDCT (slice thickness, 1 mm) twice at an interval of 6 months or more, 12 patients without changes in the lung field and 14 with clear changes in the lung field were selected as subjects. An image interpretation experiment was performed by five image interpreters. Pulmonary emphysema was followed up using two types of thick slab MinIP (thick slab MinIP 1 and 2) and multi-planar reformation (MPR), and the results of image interpretation were evaluated by receiver operating characteristic (ROC) analysis. In addition, the time required for image interpretation was compared among the three follow-up methods. The area under the ROC curve (Az) was 0.794 for thick slab MinIP 1, 0.778 for the thick slab MinIP 2, and 0.759 for MPR, showing no significant differences among the three methods. Individual differences in each item were significantly more marked for MPR than for thick slab MinIP. The time required for image interpretation was around 18 seconds for thick slab MinIP 1, 11 seconds for thick slab MinIP 2, and approximately 127 seconds for MPR, showing significant differences among the three methods. There were no significant differences in the results of image interpretation regarding the presence or absence of changes in the lung fields between thick slab MinIP and MPR. However, thick slab MinIP showed a shorter image interpretation time and smaller individual differences in the results among image interpreters than MPR, suggesting the usefulness of this method for determining the presence or absence of changes with time in the lung fields of patients with pulmonary emphysema.

The Journal of Medical Investigation : JMI


Measurement of variation in the human cerebral GABA level by in vivo MEGA-editing proton MR spectroscopy using a clinical 3 T instrument and its dependence on brain region and the female menstrual cycle.

The objectives of this study were to examine the reproducibility of the MEGA-editing J-difference technique and to determine the normal variation in the γ-aminobutyric acid (GABA) level depending on the cerebral region and its fluctuation according to the menstrual cycle as baseline data for clinical application. The participants consisted of 15 normal adult volunteers (eight men and seven women), and all measurements were repeated twice in all participants. The MEGA-editing pulses were incorporated into point-resolved spectroscopy on a 3 T instrument to obtain the J-difference editing spectra from a voxel located in the lentiform nuclei (LN), left frontal lobe (FL), and anterior cingulate cortex (AC). The GABA levels in the gray matter (GM) were compensated by the fraction ratios of the gray and white matters and cerebrospinal fluid in the measurement volume. The extent of the variation in GABA was almost the same as that observed in the major metabolites, and its reproducibility was also maintained (intraclass correlation coefficient > 0.7). GABA level was highest in LN and lowest in AC. A difference in the GABA level between the follicular and luteal phases of the menstrual cycle was found in both LN and FL, but not in AC. This technique showed the differences in the GABA levels in the GM and the region-specific decrease in the GABA levels during the women's luteal phase.


Measurements of multi-detector CT surface dose distributions using a film dosimeter and chest phantom

This paper uses film dosimetry to investigate the relationship between multiple scan parameters of multidetector CT with automatic exposure control (AEC) and the surface dose distribution produced on a chest phantom. The characteristics of the film used in the film dosimeter were evaluated with regard to linearity, relative film response, and directional dependence. Measurements with an ionization chamber dosimeter and a water phantom were used to evaluate the accuracy of the film dosimeter measurements and to validate the dose profile measurements while changing the tube current, detector dimensions and pitch. When using AEC, the surface dose distribution on the chest phantom was analyzed while changing the detector dimensions and pitch. The linearity, relative film response, and directional dependence of the film were established. The measurement difference between the film dosimeter and ionization chamber dosimeter was within +/- 5% and the dose profile measurement results were validated. It was found that the surface dose distribution changed helically in the direction of the body axis depending on the scan parameters and the phantom. Using a film dosimeter, the relationship between various multidetector CT scan parameters and the surface dose distribution on a chest phantom was investigated and clarified.


Non-invasive evaluation of the GABAergic/glutamatergic system in autistic patients observed by MEGA-editing proton MR spectroscopy using a clinical 3 tesla instrument.

Amino acids related to neurotransmitters and the GABAergic/glutamatergic system were measured using a 3 T-MRI instrument in 12 patients with autism and 10 normal controls. All measurements were performed in the frontal lobe (FL) and lenticular nuclei (LN) using a conventional sequence for n-acetyl aspartate (NAA) and glutamate (Glu), and the MEGA-editing method for GABA. The GABA level and [GABA]/[NAA] ratio were significantly lower (p < 0.01) in the FL, but not the LN, in patients with autism compared to normal controls. The [GABA]/[Glu] ratio in the FL was also significantly lower (p < 0.05) in the patients than in the normal controls, thus suggesting a possible abnormality in the regulation between GABA and Glu.

Journal of Autism and Developmental Disorders


Temporomandibular joint and 3.0T pseudodynamic magnetic resonance imaging. Part 2: evaluation of articular disc obscurity.

This study examined the relationship between temporomandibular joint (TMJ) dysfunctions and obscurity grades of interpreted anterior and posterior borders of the articular disc (Da and Dp, respectively) by 3.0 T pseudodynamic MRI. Da and Dp were classified into seven obscurity grades, and the Dp contour was classified into three types. The grades, types and TMJ function were compared by 3.0 T pseudodynamic MRI. Unobscured Da images at condylar positions posterior to the articular eminence were associated with normal TMJ function (P = 0.046 < 0.05). Unobscured Dp images at condylar positions anterior to the articular eminence were associated with normal TMJ function (P = 0.033 < 0.05). In addition, unobscured Dp images following flap insertion were associated with normal TMJ function (P = 0.043 < 0.05). There was no statistical relationship between Dp contour types and TMJ movement, but any change observed in the Dp contour during mouth opening was associated with abnormal TMJ function (P = 0.040 < 0.05). Grading of Da and Dp obscurity based on how well the areas were defined in the images, identifying the condylar positions in relation to the glenoid fossa and articular eminences, and observing the changes in Dp contour types were useful for diagnosing TMJ abnormalities.


Temporomandibular joint and 3.0T pseudodynamic magnetic resonance imaging. Part 1: evaluation of condylar and disc dysfunction.

This study describes an improved method for examining and diagnosing temporomandibular joint (TMJ) dynamics by 3.0 T pseudodynamic MRI. Clinical observation and conventional static MRI of volunteers (one without and eight with TMJ arthrosis) were followed by 3.0 T pseudodynamic MRI in positions ranging from the mouth closed to mouth fully opened. Condylar head (Cd), articular disc anterior border (Da) and articular disc posterior border (Dp) were digitized on sagittal images to determine trajectory and velocity patterns. Patients were divided into three groups based on the presence or absence of dysfunction: Group 1, no dysfunction on the right or left side of the TMJ; Group 2, dysfunction on the right or left side of the TMJ; and Group 3, dysfunction on both the right and left sides of the TMJs. In 75% of patients (12 of 16 joints), pseudodynamic TMJ analysis was useful for determining a functional abnormality. Using a points system based on three trajectory and seven velocity patterns, discs with adhesion and perforation had significantly fewer points than discs with anterior displacement (with and without reduction) and discs with no abnormality (P = 0.019 < 0.05). Trajectory and velocity patterns based on 3.0 T pseudodynamic MRI identified the affected side and determined the extent of morbidity in the Cd as well as the Da and Dp. The typical abnormal movement pattern of discs with anterior displacement (with and without reduction) and pathological structural changes of the articular disc (such as adhesion and perforation) could be identified.


強度変調放射線治療におけるradiographic filmと radiochromic filmの比較評価

Purpose: Radiographic film is generally used for inspection of dose distribution in intensity modulated radiation therapy (IMRT) at many institutions. However, the distribution of filmless systems can be expected to be used increasingly in the future. Therefore, we confirmed the utility of radiochromic film by comparing it with radiographic film that does not need an automatic processor. Result: Difference in does measured by radiographic film and radiochromic film tended to increase in the low does area, but it was limited in a range of 1.5%. Conclusion: When the dose distribution was verified in a highly accurate radiation therapy such as IMRT, the results suggested that radiochromic film can be useful in addition to radiographic film.

Japanese Journal of Radiological Technology


Manifestations of the Female Reproductive Organs on MR Images: Changes Induced by Various Physiologic States.

Unlike other reproductive organs, the uterus and ovaries are known to undergo dynamic morphologic changes according to various physiologic states. It is vitally important for radiologists when diagnosing gynecologic disorders to understand how normal female reproductive organs appear on magnetic resonance (MR) images for a given physiologic state. The authors focused on the effects of the menstrual cycle, pregnancy, and aging on MR images of normal female reproductive organs. During menstruation, the zonal architecture of the uterine corpus may be indistinct and the ovarian stroma may shrink and have lower signal intensity on both T2- and diffusion-weighted (DW) images. During periovulation, the ovarian stroma may be reach its maximum size and have high signal intensity on both T2- and DW images. Functional cysts may often be seen in ovaries of reproductive age and usually spontaneously shrink, whereas surface-epithelial inclusion cysts may be commonly seen in postmenopausal ovaries. Pregnancy-related changes, such as decidual changes in ectopic endometrial tissue and hyperreactio luteinalis in ovaries, may mimic gynecologic tumors and must be correctly diagnosed to avoid unnecessary and excessive surgical intervention. The authors offer some clues that may be helpful for making the differential diagnosis when evaluating MR images of female reproductive organs. Radiologists should, as much as practicably possible, check the physiologic states of patients before interpreting MR images.


Incidence and clinical correlation of intracranial hemorrhages observed by 3-tesla gradient echo T2*-weighted images following intravenous thrombolysis with recombinant tissue plasminogen activator

The purpose of this study was to determine the incidence and clinical correlation of intracranial hemorrhages (ICHs) detected by 3-tesla gradient echo T(2)*-weighted images after intravenous recombinant tissue plasminogen activator (rt-PA) administration. We included 43 consecutive patients with anterior-circulation ischemia who underwent MRI studies before and after thrombolysis. Each hemorrhage was classified as a hemorrhagic infarction (HI) or parenchymal hemorrhage (PH) according to the European Cooperative Acute Stroke Study definition. The clinical outcome was defined as an improvement (> or =4-point reduction) or deterioration (> or =4-point increase) based on a comparison between the initial and the 30-day NIHSS scores. The incidence of ICHs was 58%, and the HI rate was 52%; both were higher than the rates reported in the literature. Most of the patients with HI improved clinically, and these patients had second MRAs that showed recanalization. None of the patients with PH demonstrated improvement. Three-tesla MRI may reveal a higher frequency of HI type hemorrhages than lower-field MRIs, and HI may be a predictor of good recovery by reflecting the presence of recanalization. The rate of PH in our study was low compared to other studies, probably due to the lower dosage of rt-PA.


肺がんCT検診のための画像選別法

肺がんCT検診のための画像選別法

医療施設は多様な撮影装置の画像,また同一撮影装置においても撮影条件の異なる画像を取り扱っている.肺がんCT検診のコンピュータ支援診断(CAD)を臨床現場で利用するためには,対象となる胸部CT画像を選別する手法が求められる.DICOM画像の付帯情報の中で検査部位は記述されていない場合が多い.本論文ではDICOM画像の付帯情報でCT画像を選別し,画像情報を用いて検査部位を選別する手法を研究開発する.本手法をCT画像253例,MR画像20例,PET画像20例に適用して有効性を示す.

The Transactions of the Institute of Electronics, Information and Communication Engineers D

電子情報通信学会論文誌(D)


Diffusion-weighted magnetic resonance imaging of ovarian tumors: differentiation of benign and malignant solid components of ovarian masses.

We evaluated the feasibility of diffusion-weighted imaging (DWI) with apparent diffusion coefficient (ADC) measurement in differentiating benign and malignant ovarian tumors. Surgically proven 49 ovarian tumors (39 malignant/borderline malignant and 10 benign) were examined. The solid portion of all 39 malignant tumors showed homogeneous or heterogeneous high intensity on DWI, whereas only 3 of the 10 benign tumors (3 thecomas) showed high intensity. The mean (SD) ADC value in the 39 malignant tumors (1.03 [0.19]) was significantly lower than that in 10 benign tumors (1.38 [0.30]). A relatively low ADC (1.08-1.20) in the 3 thecomas may reflect their abundant cellular nature, and the presence of low intensity on T2-weighted images was suggestive for benign fibrous tumor. Low intensity on DWI with high ADC may suggest benign lesions; however, it may be occasionally difficult to differentiate benign and malignant lesions only on the basis of DWI.


Use of a diagnostic positron emission tomography-computed tomography system for planning radiotherapy positioning: distortion of the tabletop.

The aim of this study was to evaluate distortion of the tabletop in a diagnostic positron emission tomography-computed tomography (PET-CT) system to determine its suitability for planning radiotherapy positioning. Distortion of the tabletop was compared among PET-CT, lineac CT, and CT simulator systems. A phantom or angiography catheter was fixed to the tabletop and imaged after iron plate weight loading. The acquired images were analyzed using radiotherapy planning software. Distortion of the tabletop was measured based on the displayed coordinates. Sinking represented the greatest distortion of the tabletop in all systems. Using the same baseline, the maximum sinking were -0.4, -0.2, and +0.4 cm, respectively. The distortion of the tabletop in the PET-CT system was more similar to that in the lineac CT than in the CT simulator system. Distortion of the tabletop in a diagnostic PET-CT system may be within the acceptable range to allow its use for planning radiotherapy positioning.


How to manage RI venography in pre-orthopedic surgery patients

The preoperative evaluation of venous thromboembolism (VTE) is important to avoid complications, because VTE is often induced by orthopedic surgery. We focused on radioisotope venography (RIV) using 99mTc-macroaggregated human serum albumin, examining orthopedic patients. We conducted 34 examinations in 33 patients who were referred for RIV and lung perfusion scintigraphy for the pre-orthopedic operative evaluation of VTE. Two board-certified (one nuclear medicine board-certified) radiologists interpreted the images based on the following: (1) flow defect of the lower extremities; (2) interruption of flow; (3) irregular or asymmetric filling of the deep vein (low flow); (4) presence of collateral vessels; and (5) abnormal RI retention on delayed-phase images. Scoring was based on a 5-point scale, and more than 2 points was considered VTE positive. Abnormal findings were noted in 27 of the 34 examinations performed in the 33 patients and normal findings in the other 7 examinations. According to the RI score, 21 patients were classified into the VTE-positive group and 12 into the VTE-negative group. Surgery was canceled because of advanced age and respiratory dysfunction in 2 of the 21 patients in the VTE-positive group. Of the 19 patients who underwent surgery, an IVH filter was placed before surgery in 2 and anticoagulant treatment with heparin and warfarin was initiated on the day of surgery in 12 to prevent postoperative VTE, and only one of the patients receiving anticoagulant treatment developed PTE after surgery. Surgery was canceled due to advanced age and at patient's request in 2 of 12 patients in the VTE-negative group. Anticoagulant treatment with heparin/ warfarin was performed to prevent postoperative VTE in only 3 patients: one with a past medical history of pulmonary infarction, one with atrial fibrillation, and one suspected of having antiphospholipid antibody syndrome. No patient in the VTE-negative group developed VTE after surgery. The preoperative identification of patients with VTE by RIV might be useful for perioperative management and the evaluation of preventive measures against postoperative VTE.


High-dose-rate brachytherapy for patients with maxillary gingival carcinoma using a novel customized intraoral mold technique.

OBJECTIVE: The purpose of this study was to introduce a novel customized intraoral mold treatment for maxillary gingival carcinoma (UGC). STUDY DESIGN: Two patients with UGC were treated as salvage therapy using this technique. The mold was designed to keep normal soft tissues adjacent to the tumor away from the radioactive source as much as possible, and it was shielded by lead. The radiation dose on the buccal mucosa and tongue was measured at the inner and outer surfaces of the intraoral mold before starting high-dose-rate brachytherapy by the remote afterloading system, and was reduced to almost one tenth. RESULTS: The patient had no recurrence and no severe adverse effects on the normal soft tissue adjacent to the tumor until the end of the follow-up period. CONCLUSION: High-dose-rate brachytherapy using the novel customized intraoral mold might be a treatment option of not only salvage therapy, but definitive therapy of UGC.

Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontics


Radiographic comparison between male and female patients with lumbar spondylolysis.

We studied the lumbar spines of 117 adults (39 women and 78 men) with spondylolysis unrelated to low back pain using multidetector computed tomography (CT). Of the 117 subjects with spondylolysis, including five with multiple-level spondylolysis, there were 124 vertebrae with spondylolysis. In adult lumbar spines with unilateral spondylolysis, there was no significant difference between the incidence of spondylolisthesis in female and male subjects. However, in those with bilateral spondylolysis, there was a significantly higher incidence of spondylolisthesis in female subjects (90.9%) than in males (66.2%). Furthermore, females with bilateral spondylolysis had significant more slippage than males. Lumbar index and lumbar lordosis were not significantly different between male and female subjects, and did not significantly correlate with slippage. In conclusion, to treat acute spondylolysis in adolescents, it is important to obtain bony union at least unilaterally, especially in female subjects, to prevent further slippage.

The Journal of Medical Investigation : JMI


Accuracy of computed tomography attenuation measurements for diagnosing anemia.

The purpose of this study was to determine which computed tomography (CT) attenuation parameter was the most appropriate to predict the presence or severity of anemia. The subjects of the study wer 500 patients who had undergone a peripheral blood examination within 24 h of an unenhanced CT scan. Regions of interest were placed in the left ventricular (LV) cavity, thoracic and abdominal aortic lumens, inferior vena cava, and interventricular septum. The CT attenuation difference between the LV cavity and interventricular septum was also calculated. The relation between these measurements and the blood hemoglobin level was analyzed. In addition, using several selected parameters, a receiver operating characteristic (ROC) analysis was also performed. The difference in CT attenuation between the LV cavity and interventricular septum revealed the greatest correlation. ROC analyses also revealed the greatest area under the ROC curve in the differences between CT attenuation. The best quantitative method for the diagnosis of anemia was the difference in CT attenuation between the left ventricle and interventricular septum.


A case of metastatic malignant melanoma of the ovary with a multilocular cystic appearance on MR imaging.

Ovarian metastasis from malignant melanoma is rare and usually appears as a solid ovarian mass. We report a case of ovarian metastasis from cutaneous malignant melanoma that proved to be a diagnostic dilemma. The ovarian metastasis exhibited a multilocular cystic appearance on magnetic resonance imaging, mimicking a mucinous ovarian tumor with massive ascites.


Incidence of lumbar spondylolysis in the general population in Japan based on multidetector computed tomography scans from two thousand subjects.

Epidemiological analysis using CTs. To investigate the true incidence of lumbar spondylolysis in the general population in Japan. Although there have been several reports on the incidence of lumbar spondylolysis, they had some weakness. One of them concerns the subjects investigated, because the incidence of lumbar spondylolysis varies considerably, and some patients are asymptomatic. In addition, most of the past studies used plain radiograph films or skeletal investigation. Therefore, the past reported incidence may not correspond to that of the general population. We reviewed the computed tomography (CT) scans of 2000 subjects (age: 20-92 years) who had undergone abdominal and pelvic CT on a single multidetector CT scanner for reasons unrelated to low back pain. We reviewed them for spondylolysis, spondylolytic spondylolisthesis, and spina bifida occulta (SBO) in the lumbosacral region. The grade (I-IV) of spondylolisthesis was measured using midsagittal reconstructions. Lumbar spondylolysis was found in 117 subjects (5.9%). Their male-female ratio was 2:1. Multiple-level spondylolysis was found in 5 subjects (0.3%). Among these 117 subjects, there were 124 vertebrae with spondylolysis. Of them, 112 (90.3%) corresponded to L5, and 26 (21.0%) had unilateral spondylolysis.SBO was found in 154 subjects. Of them, 25 had spondylolysis (16.2%), whereas, in 1846 subjects without SBO, 92 had spondylolysis (5.0%). The incidence of spondylolysis among the patients with SBO was significantly higher than that in subjects without SBO (Odd ratio was 3.7-fold).Of 124 vertebrae with spondylolysis, 75 (60.5%) showed low-grade (Meyerding grade I or II) spondylolisthesis, and no subject presented high-grade spondylolisthesis. Spondylolisthesis was found in 74.5% of the subjects with bilateral spondylolysis, and in 7.7% of those with unilateral spondylolysis. The incidence of lumbar spondylolysis in the Japanese general population was 5.9% (males: 7.9%, females: 3.9%).


Diffusion-weighted magnetic resonance imaging of endometrial cancer: differentiation from benign endometrial lesions and preoperative assessment of myometrial invasion.

Uterine endometrial cancer is the most common gynecologic malignancy, and benign endometrial hyperplasia or polyps should be differentiated from endometrial cancer. In evaluating endometrial cancer on magnetic resonance imaging (MRI), the assessment of the depth of myometrial invasion is important because it closely correlates with the patient's prognosis. To verify the feasibility of diffusion-weighted magnetic resonance imaging (DWI) to distinguish benign and malignant endometrial lesions, and to evaluate myometrial invasion of endometrial cancer. Sixty-seven endometrial lesions including 45 cancers and 22 benign lesions (hyperplasia and polyps) were evaluated by DWI with apparent diffusion coefficient (ADC) measurement. The staging accuracies of DWI and gadolinium-enhanced T1-weighted images in the assessment of myometrial invasion were evaluated in 33 patients with endometrial cancer. The ADC values (x10(-3) mm(2)/s) in cancer and benign lesions were 0.84+/-0.19 and 1.58+/-0.36, respectively (P<0.01). The staging accuracy (superficial or deep myometrial invasion) was 94% for DWI and 88% for gadolinium-enhanced T1-weighted images. Coexisting adenomyosis and infiltrative myometrial invasion caused staging errors on gadolinium-enhanced T1-weighted images, whereas DWI could demonstrate the tumor extent correctly. DWI provides helpful information in evaluating benign and malignant endometrial lesions.


Risk factors for radiation pneumonitis caused by whole breast irradiation following breast-conserving surgery.

We evaluated risk factors of radiation pneumonitis (RP) after whole breast irradiation following breast-conserving surgery. Four hundred and seventy-two cases underwent whole breast irradiation with tangential field following breast-conserving surgery in our hospital, between January 2005 and April 2007. Of these cases, we performed statistical analyses for 423 breasts of 413 patients, using a pulmonary dose-volume histogram. Patient characteristics, treatment regimens and irradiation methods were included as variables in the analyses on risk factors of RP. As a result, 89 breasts of 84 cases (21%) were diagnosed with RP. The version 3.0 of the NCI Common Terminology Criteria for Adverse Events was used to evaluate the grade of pneumonitis: 77 cases (18.2%) were diagnosed as Grade 1 RP, 10 cases (2.3%) as Grade 2, and 2 cases (0.5%) as Grade 3. Multivariate analysis indicated that the significant risk factors for RP were central lung distance (CLD) (>1.8 cm) and the short axis length of the radiation field. The incidence of radiation-induced bronchiolitis obliterans organizing pneumonia (BOOP) syndrome significantly correlated only with CLD. The lung volume within the radiation field was shown to be a significant risk factor for RP and radiation-induced BOOP syndrome.


Thallium-201 chloride scintigraphy in soft tissue tumors.

We report the findings of Thallium-201 chloride ((201)TlCl) scintigraphy and consider how to use this technique to evaluate the character of soft tissue lesions. We enrolled 91 consecutive patients (45 males and 46 females, age range 8-91-years-old). Nineteen patients were malignant and 72 were benign. Patients were scanned 15 minutes (early phase) and 3 hours (delayed phase) after (201)TlCl injection. More intense uptake in the lesion compared to the normal side was considered as 'high', the same degree of uptake was considered 'iso', and decreased uptake was 'low'. The retention index (RI) was calculated in 9 patients in the malignant group and in 16 patients in the benign group. In malignant tumors, 15 of 19 patients showed high uptake in both the early and delayed phases. One malignant fibrous histiocytoma patient was high only in the delayed phase and 1 liposarcoma patient was high only in the early phase. Two liposarcoma patients showed an iso uptake in both phases. One of these patients was pathologically diagnosed as a myxoid type. In benign lesions, no lipoma showed increased uptake. All neurogenic tumors except for 2 demonstrated high uptake. All 3 ganglions of the lower extremities showed iso uptake. Most inflammatory diseases showed increased uptake. Clinically-considered benign patients consisted of tumorous lesions or inflammatory disease. Only 2 patients were considered 'low', and these were diagnosed as intramuscular hematoma and cyst. RI was variable in both malignant and benign lesions and no statistically significant difference was seen between malignant and benign lesions by t-test (p=0.72). A high (201)TlCl uptake lesion is more frequently seen in malignant tumors, but regardless of whether the tumor is benign or malignant, according to the histopathological variety, the (201)TlCl uptake pattern can not be the only indicator to differentiate malignant from benign tumors. We ultimately need to evaluate the nature of tumors by a combination of several imaging techniques.


Comparison with Bone Scintigraphy and MDCT Findings in Patients with Round Focal Accumulation on Bone Scintigraphy

骨シンチグラフィにおける結節状の異常集積とMDCT所見との比較


Clear-cell sarcoma of the small intestine detected by FDG-PET/CT during comprehensive examination of an inflammatory reaction.

Clear-cell sarcoma (CCS) is a rare, malignant, soft-tissue tumor, which involves the extremities, particularly the foot and foot joint tendons and aponeuroses. It is morphologically similar to but histochemically distinct from malignant melanoma. CCS arising in the gastrointestinal tract has rarely been reported. The prognosis of CCS is reportedly poor because of the high incidence of metastases at the time of initial diagnosis and the high frequency of recurrence. We report a case of early-stage CCS of the small intestine detected by (18)F-fluoro-2-deoxy D-glucose Positron Emission Tomography/Computed Tomography (FDG-PET/CT) during the comprehensive examination of an inflammatory reaction. In this case, FDG-PET/CT clearly visualized the lesion, which was difficult to detect by contrast CT.


A case of von Recklinghausen's disease with coincident malignant peripheral nerve sheath tumor and gastrointestinal stromal tumor.

(18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET/CT) was performed to evaluate a left femoral subcutaneous mass in a patient with von Recklinghausen's disease (vRd) that gradually enlarged, causing pain and numbness. The left femoral mass showed intense FDG uptake with the maximum standardized uptake value (SUVmax) of 9.0. Other subcutaneous masses considered benign and neurogenic in nature also showed FDG uptake (SUVmax around 3 or less), but the degree of FDG uptake differed considerably from the left femoral mass. This observation suggested that the degree of FDG uptake may be a useful indicator of malignant transformation. Incidentally, PET/CT also showed an asymptomatic large abdominal mass with intense FDG uptake (SUVmax 8.8). The abdominal mass was resected and confirmed as gastrointestinal stromal tumor (GIST) of the small intestine. Three months later, the left femoral mass was operated on and pathologically diagnosed as a malignant peripheral nerve sheath tumor (MPNST). Various malignant diseases are known to occur with high frequency in vRd. Therefore, vRd patients need to have periodical examinations including PET/CT. We present a rare case of a patient with vRd with a MPNST of the left femur and coincidental GIST of the small intestine. February, 2009.

The Journal of Medical Investigation : JMI


Evaluation of Initial Diffusion-weighted Image Findings in Acute Stroke Patients using a Semiquantitative Score.

We evaluated the usefulness of rating diffusion-weighted images (DWI) using a semiquantitative score modified from the Alberta Stroke Programme Early CT Score (ASPECTS) to predict deterioration of neurological symptoms in patients with hyperacute ischemic stroke who had undergone thrombolytic therapy with recombinant tissue plasminogen activator (rt-PA). We examined 22 patients with acute stroke (14 men, 8 women, mean age 72.5 years) treated with intravenous rt-PA. All were assessed using the National Institutes of Health Stroke Scale (NIHSS) and underwent emergent magnetic resonance (MR) imaging within 3 hours and 24 hours of stroke onset. Patients were divided into a deteriorated group (16 patients), in which NIHSS scores were increased after thrombolysis, and a non-deteriorated group (6 patients). We compared the DWI score, ASPECTS, and volume of hyperintense ischemic lesion on DWI (DWI volume) of the 2 groups and examined correlations between these scores and initial NIHSS score or DWI volume. The DWI score and ASPECTS tended to be lower in the deteriorated group than the non-deteriorated group. In addition, with a cutoff value<or=7, the DWI score could discriminate the deteriorated group from the non-deteriorated group with a sensitivity of 50% and specificity of 87.5%, whereas for ASPECTS, sensitivity was 50% and specificity, 81.2%. The DWI score, ASPECTS, and DWI volume had no correlation with NIHSS score but weak negative correlations with the DWI volume (P<0.01; Spearman's test). Comparing initial NIHSS score with each DWI score and DWI volume, the non-deteriorated group tended to have higher DWI scores and smaller DWI volumes than the deteriorated group, but there was no statistical difference between initial NIHSS and DWI scores. Though the DWI score was not statistically different, the threshold would be set to 6 points or above. Comparing initial DWI score with volume, patients with low DWI scores tended to show large variation in DWI volume and patients with small DWI volume showed large variation in DWI scores. There was no relation between hemorrhagic change and symptoms in either group. The semiquantitative DWI score easily evaluated extent of acute ischemic lesion on DWI and might be used to predict patient outcome after thrombolytic therapy more accurately than ASPECTS or DWI volume.


Hyperintense uterine myometrial masses on T2-weighted magnetic resonance imaging: differentiation with diffusion-weighted magnetic resonance imaging.

The objective was to determine whether diffusion-weighted imaging (DWI) might be useful in differentiating uterine leiomyomas exhibiting hyperintensity on T2-weighted images from malignant lesions. Thirty-four uterine myometrial lesions including 7 malignant tumors and 27 leiomyomas (6 cellular leiomyomas [CLM] and 21 degenerated leiomyomas [DLM]) were evaluated. The apparent diffusion coefficients (ADC) in cellular portions of the lesions were measured (10(-3) mm2/s). All malignant tumors showed high signal intensity on DWI with low ADC (mean [SD], 0.79 [0.26]), which was significantly lower (P < 0.01) than that in benign leiomyomas (1.51 [0.33]). The ADC in CLM (1.18 [0.16]) was significantly lower (P < 0.01) than that in DLM (1.60 [0.30]) and higher (P < 0.05) than that in malignant tumors. It was difficult to differentiate malignant tumors from leiomyomas on the basis of signal intensity on DWI; however, the ADC measurement may be helpful to distinguish malignant tumors, CLM, and DLM.


Adenosarcoma of the uterus: magnetic resonance imaging characteristics.

Adenosarcoma of the uterus is a rare tumor containing benign glandular epithelial and malignant mesenchymal elements. Typical adenosarcoma is a low-grade tumor, presents as a large polypoid mass occupying the endometrial cavity, and may protrude into the vaginal cavity. The presence of small hyperintense cysts scattered within the mass on T(2)-weighted imaging, reflecting glandular epithelial components, and relatively low signal intensity on high b-value diffusion-weighted imaging, reflecting its low-grade nature, may be characteristic findings.


Clear cell adenocarcinoma of the female urethra: magnetic resonance imaging

Clear cell adenocarcinoma of the female urethra is a rare malignant tumor arising from urethral diverticulum or paraurethral ducts and glands, and extends to the submucosa surrounding the urethra. In the advanced stage, the tumor may involve adjacent organs such as the vagina, and may mimic gynecologic malignancy. We report 2 cases in which magnetic resonance imaging could reveal their urethral origin by detecting the normal urethra within the mass as targetlike appearance on axial T2-weighted image.


[Comparison of 3 Tesla whole heart coronary MRA (WHCA) with 1.5 Tesla]

1.5Tと比較した3TにおけるWhole Heart Coronary MRA(WHCA)の検討

Whole heart coronary MRA (WHCA) is a noninvasive method used to image all coronary arteries with cardiac and real-time respiratory gating. We compared the coronary depiction ability of 3T WHCA with that of 1.5T using healthy volunteers. In addition, we compared the study performance rate, which might differ at 3T and 1.5T due to the difference in specific absorption rate (SAR) limits. The coronary artery was classified into nine segments, based on the classification of the American Heart Association (AHA). Each observer was asked to evaluate WHCA with the three-point scale rating for each segment, and to measure the visible length of each coronary artery utilizing reconstructed CPR and VR images. Depiction at 3T was superior to that at 1.5T. The completion rate of study was 100% at 1.5T, but just 63% at 3T owing to SAR limits. Thus it was suggested that 3T WHCA might be feasible with the advantage of high depiction ability, if adequate SAR reduction techniques were developed.

Japanese Journal of Radiological Technology


医療用自己遮蔽型PETサイクロトロン及び電子リニアックにおける中性子束の箔放射化法による測定

Japanese Journal of Radiation Safety Management

日本放射線安全管理学会誌


Diffusion-weighted magnetic resonance imaging of urinary epithelial cancer with upper urinary tract obstruction: preliminary results

BACKGROUND: Various malignant tumors of the body show high signal intensity on diffusion-weighted magnetic resonance imaging (DWI). In the genitourinary region, DWI is expected to have a role in detecting urinary epithelial cancer noninvasively. PURPOSE: To demonstrate the feasibility of DWI for the diagnosis of urinary epithelial cancer with upper urinary tract obstruction. MATERIAL AND METHODS: Twenty upper urinary tract cancers in 16 patients were evaluated by high-b-value DWI (b=800 s/mm(2)). The signal intensity was visually evaluated, and the apparent diffusion coefficients (ADCs) were measured. RESULTS: All urinary epithelial cancers showed high signal intensity on DWI. The ADC in cancerous lesions was 1.31+/-0.27 x 10(-3) mm(2)/s, which was significantly lower than that of the lumens of the ureter or renal pelvis (3.32+/-0.44 x 10(-3) mm(2)/s; P<0.001). Maximum intensity projection images of DWI in combination with static-fluid MR urography provided three-dimensional entire urinary tract imaging with the extension of tumors. CONCLUSION: DWI is useful in the tumor detection and in evaluating the tumor extension of urinary epithelial cancer in patients with upper urinary tract obstruction.


Susceptibility-weighted MRI of endometrioma: preliminary results

OBJECTIVE: Susceptibility-weighted MRI combines magnitude and phase information from fully velocity-compensated gradient-echo sequences and depicts as signal voids the susceptibility effects caused by local inhomogeneity of the magnetic field. Our objective, based on MRI of 60 pathologically proven ovarian cystic lesions, including 42 endometriomas and 18 nonendometrial cysts, was to evaluate hemosiderin deposition within the walls of endometriomas on susceptibility-weighted MR images. Two radiologists blinded to the final diagnosis retrospectively reviewed the images in consensus. CONCLUSION: On susceptibility-weighted MR images, punctate or curved linear signal voids along the cyst wall were observed in 39 endometriomas (92.9%) and in no nonendometrial cysts. The signal voids were more prominent on 3-T than on 1.5-T images, reflecting the higher sensitivity of 3-T MRI to magnetic susceptibility effects. Thirty-two endometriomas (76.2%) met definitive MRI criteria, that is, hyperintensity on T1-weighted images and hypointensity on T2-weighted images, and 41 endometriomas (97.6%) were correctly diagnosed with susceptibility-weighted MRI.


Ovarian fibromatosis: magnetic resonance imaging findings with pathologic correlation

Ovarian fibromatosis is a rare benign nonneoplastic condition with ovarian enlargement in young women and characterized by a proliferation of collagen-producing spindle cells surrounding normal ovarian structures. We reported magnetic resonance findings of a case that the affected ovarian parenchyma with follicles was surrounded by very low intense thick fibrous tissue on T2-weighted images such as "black garland" around the ovary. The magnetic resonance findings well reflected the pathological feature of the disease and may be diagnostic.


Ischemic Findings of T2*-Weighted 3-Tesla MRI in Acute Stroke Patients.

We compared ischemic findings on gradient echo-type T(2)*-weighted images at 3-tesla MRI (T(2)*WI) in patients with acute ischemia and major vessel occlusion, and stroke patients with lacunar infarction or branch atheromatous disease. Our study population consisted of 45 patients with acute stroke. They underwent 3-tesla MRI within 12 h of stroke onset. Included were 24 patients (13 men and 11 women, mean age 68 years) with major vessel occlusion and 21 patients (11 men and 10 women, mean age 69 years) with minor infarction such as lacunar infarcts or branch atheromatous disease. We classified vascular ischemic findings of T(2)*WI into 3 sign categories, i.e. artery susceptibility sign, cortical vessel sign (hypointensity and enlargement of the cortical vessels) and brush sign (hypointensity of vessels in the deep white matter). Decreased intensity in the ischemic parenchyma was designated ischemic tissue sign. We compared regions of interest in the hypoperfused area on flow-sensitive alternating inversion recovery (FAIR) images with our vascular ischemic findings. None of the vascular ischemic signs nor the ischemic tissue sign were found in patients with minor vessel disease. All 24 patients with major vessel occlusion manifested the cortical vessel sign, 23 the brush sign. The area with ischemic vessel signs on T(2)*WI was almost as large or somewhat smaller than the hypoperfused area on FAIR images. Compared to the contralateral side, 14 of 24 patients (58.3%) with major vessel occlusion showed decreased intensity in the ischemic parenchyma (ischemic tissue sign). Region of interest measurements on FAIR images demonstrated greater hypoperfusion in the area classified as ischemic tissue sign on T(2)*WI. Ischemic vessel signs and the ischemic tissue sign on T(2)*WI at 3 T would be useful to evaluate the extensive ischemia due to major vessel occlusion and may be correlated with the blood-oxygen-level-dependent effect due to increased deoxyhemoglobin. The ischemic tissue sign may be reflective of severe ischemia.


DICOM画像の個人情報保護のための匿名化システム

DICOM画像の個人情報保護のための匿名化システム

医用画像を二次利用する場合には,医療施設の倫理審査委員会に申請して認可を得た後に個人情報の保護を行う必要がある.これには患者へのインフォームドコンセントや許諾を得た患者の個人情報の識別を防止する匿名化が求められている.匿名化の対象となる情報は医療施設の倫理審査委員会の指針に沿って実施する必要があり,これは医療施設で異なるのが現状である.そこで,多数の医療施設に適用でき,かつ大規模なDICOM画像を効率的に匿名化できるシステムの開発が求められている.本論文では,医療施設の匿名化ポリシを柔軟に設定でき,大規模なDICOM画像をオンライン処理で匿名化できるシステムを研究開発する.このシステムを八つの医療施設で臨床運用してその有効性を示す.

The Transactions of the Institute of Electronics, Information and Communication Engineers D

電子情報通信学会論文誌(D)


High-b-value diffusion-weighted magnetic resonance imaging of pancreatic cancer and mass-forming chronic pancreatitis: preliminary results

BACKGROUND: Mass-forming chronic pancreatitis may mimic a pancreatic cancer on dynamic computed tomography (CT) and magnetic resonance (MR) imaging, and preoperative differential diagnosis is often difficult. Recently, the usefulness of diffusion-weighted MR imaging (DWI) in the diagnosis of pancreatic cancer has been reported in several studies. PURPOSE: To determine whether high-b-value DWI can distinguish pancreatic cancer from benign mass-forming chronic pancreatitis. MATERIAL AND METHODS: Twenty pancreatic cancers and four cases of mass-forming chronic pancreatitis were evaluated by high-b-value DWI (b=800 s/mm(2)). The signal intensity on DWI was visually evaluated, and the isotropic apparent diffusion coefficients (ADCs) were measured. RESULTS: All twenty pancreatic cancers showed high signal intensity (18 showed very high, two showed slightly high) on DWI. None of the mass-forming chronic pancreatitis cases showed very high intensity (three showed iso to low, one showed slightly high) on DWI. The ADCs in the pancreatic cancer and mass-forming chronic pancreatitis were 1.38 +/- 0.32 x 10(-3) mm(2)/s and 1.00 +/- 0.18 x 10(-3) mm(2)/s, respectively (P < 0.05). CONCLUSION: On high-b-value DWI, most pancreatic cancers showed very high signal intensity, and may hence be distinguished from benign mass-forming chronic pancreatitis based on our preliminary results.


Magnetic resonance manifestations of endometrial cysts at 3 T compared with 1.5 T

OBJECTIVE: To evaluate the feasibility of magnetic resonance (MR) imaging at 3 T compared with 1.5 T while focusing on the shading sign of endometrial cysts on T2-weighted images. METHODS: Fifteen ovarian endometrial cysts in 10 patients underwent pelvic MR scans on 3-T and 1.5-T scanners. Fast spin-echo T2-weighted images were obtained. The images were evaluated qualitatively for the presence of the shading sign. Quantitative evaluation was performed by comparing the cyst-to-muscle signal intensity ratio at 3 T and that at 1.5 T. RESULTS: The signal intensity of the cysts was lower at 3 T than that at 1.5 T by visual evaluation. In 2 lesions, the shading sign was demonstrated at 3 T but was not at 1.5 T. The cyst-to-muscle signal intensity ratio at 3 T was significantly lower than that at 1.5 T. CONCLUSION: Magnetic resonance imaging at 3 T is useful for the diagnosis of endometrial cysts with better demonstration of the shading sign on T2-weighted images.


BACKGROUND: The objective of this article is to define the imaging characteristics of ancient schwannoma, which is a rare variant of benign schwannoma with degenerative changes, arising in the female pelvis simulating ovarian tumors. METHODS: Eleven surgically proven ancient schwannomas of the female pelvis were evaluated retrospectively on the basis of CT and MR findings. RESULTS: Typical intra-pelvic schwannoma was a neurologically asymptomatic large mass, which may situate at presacral or lateral pelvic region with the continuity to the nerve or neural foramen. Ancient schwannomas manifested as encapsulated solid masses with random or eccentric cystic areas, or as cystic masses with marginal crescent-shaped or nodular solid components. Hemorrhagic changes and calcifications were often observed on MRI and CT respectively. To detect ipsilateral normal ovary and to demonstrate centripetal displacement of the adjacent rectum or iliac vessels were helpful to diagnose the tumor as an extra-ovarian mass situated at the extraperitoneal region. CONCLUSIONS: Diagnosis of ancient schwannoma before surgical treatment is important and should be made by its characteristic clinical and imaging findings.


Effective bladder preservation strategy with low-dose radiation therapy and concurrent intraarterial chemotherapy for muscle-invasive bladder cancer.

PURPOSE: The aim of this study was to evaluate retrospectively the toxicity and response, bladder preservation, and survival of patients with muscle-invasive bladder cancer treated with multimodality therapy consisting of low-dose radiation therapy (RT) and concurrent intraarterial chemotherapy (IACT). METHODS AND MATERIALS:. Between November 1999 and July 2005, a total of 27 consecutive, previously untreated patients with muscle-invasive bladder cancer underwent transurethral bladder tumor resection followed by concurrent low-dose RT and IACT. Patients who achieved a complete response (CR) were followed up closely without further therapy, and patients who did not achieve a CR underwent further treatment. RESULTS: Complete response was achieved in 22 of 27 patients (81%). Of these 22 patients, 7 developed recurrences, and 3 died of their disease. In five patients who did not achieve CR, one died from bone metastases. The 3-year overall survival rate was 81%, with a median follow-up time of 27 months; and 22 of 27 patients (81%) with a preserved bladder were tumor-free at the last follow-up. Three patients (11%) developed grade 3 acute hematological toxicity. CONCLUSION: Multimodality therapy consisting of low-dose RT and concurrent IACT for muscle-invasive bladder cancer can achieve survival rates similar to those in patients treated with radical cystectomy, with successful bladder preservation and minimal adverse effects.


A case of polypoid endometriosis: MR pathological correlation

We report a case of polypoid endometriosis and correlate the MRI findings with the pathological findings. The polypoid endometriosis appeared as multiple polypoid masses protruding into the adjacent pelvic organs, including the uterus and rectum. The masses were found to show hyperintensity on T(2) weighted images, which was similar to the signal intensity of the uterine endometrium, reflecting the presence of abundant endometrial-type glands. The masses were also surrounded by hypointense rim-like structures on T(2) weighted images. These structures were confirmed by pathology to correspond with fibrous tissues arising from endometriosis. These features, together with an intense enhancement similar to the adjacent uterus, may be a diagnostic clue to this rare entity.


Prognostic significance of HIF-2alpha expression on tumor infiltrating macrophages in patients with uterine cervical cancer undergoing radiotherapy.

Hypoxia-inducible factor (HIF)-2alpha, a basic helix-loop-helix (bHLH)-PAS protein, is the principal regulator of the hypoxic transcriptional response. An immunohistochemical study reported strong HIF-2alpha expression in the cytoplasm of tumor infiltrative macrophages (TIMs). Thus we assessed the expression of HIF-2alpha in human cervical cancer tissue before radiation therapy and its relationship to the clinical outcome. Seventy three patients with histologically proven primary advanced squamous cell carcinoma of the uterine cervix underwent radiotherapy in Tokushima University Hospital after biopsy specimens were taken. Among 73 specimens stained for HIF-2alpha, 53 (72.6%) exhibited HIF-2alpha immunoreactivity in the TIMs. In only 5 of 73 cases, HIF-2alpha immunoreactivity was observed in the nuclei of tumor cells. The HIF-2alpha positive cell count ratio in TIMs was associated with disease-free survival (DFS) with the worst DFS (p=0.024) being in cases in the group with a high positive cell count ratio. A high HIF-2alpha positive cell count ratio in TIMs increased the risk of local recurrence (p=0.0142). These findings might suggest that the ratio of the HIF-2alpha positive cell in TIMs may be a new predictive indicator for prognosis before radiation therapy for uterine cervical cancer.

The Journal of Medical Investigation : JMI


Comparison of 3.0-and 1.5-tesla diffusion-weighted imaging in the visibility of breast cancer.

PURPOSE: The aim of this study was to compare diffusion-weighted imaging (DWI) at 3.0 T and 1.5 T by evaluating the apparent diffusion coefficient (ADC) value and visibility of breast cancer in the same patients. MATERIALS AND METHODS: A total of 13 patients (16 lesions) with breast cancer underwent DWI at 3.0 T and 1.5 T. Tumors were classified into two groups based on the lesion size. The ADC values were measured, and visibility of the tumors was scored blindly. RESULTS: No significant difference was found for ADC values between 3.0 T and 1.5 T in either group (P > 0.05). All of the large lesions were visible clearly at both magnetic field strengths, and image scores were not different (P > 0.05). In contrast, small lesions were more clearly visible and had better image scores at 3.0 T than at 1.5 T (P < 0.001). CONCLUSION: Small cancers were more clearly visible on DWI at 3.0 T than 1.5 T.


Does partial volume corrected maximum SUV based on count recovery coefficient in 3D-PET/CT correlate with clinical aggressiveness of non-Hodgkins lymphoma?

There is much controversy about the correlation between the degree of 2-[(18)F]fluoro-2-deoxy-D: -glucose (FDG) uptake and clinical aggressiveness of non-Hodgkin's lymphoma (NHL). In this study, we investigated whether partial volume corrected FDG uptake based on count recovery coefficient in 3D-positron emission tomography (PET)/computed tomography (CT) correlates with the clinical aggressiveness of NHL and improves diagnostic accuracy. Forty-two patients with NHL underwent FDG-PET/CT scans (26 aggressive NHLs and 16 indolent ones). Count recovery curve was obtained using NEMA 2001 body phantom. Scan protocol and reconstructive parameters in the phantom study were the same as those in a clinical scan except for emission time. Relative recovery coefficient (RC) was calculated as RC = A/B (A, maximum pixel count of each hot sphere; B, maximum pixel count of greatest sphere). Partial volume corrected maximum count of standardized uptake value (PVC-SUV) was calculated as PVC-SUV = NC-SUV/RC (NC-SUV: non-corrected maximum count of SUV). Three parameters (NC-SUV, PVC-SUV, and size) between aggressive and indolent NHLs were compared. Significant differences were shown in all parameters between aggressive and indolent NHLs. Means +/- SD of NC-SUV, PVC-SUV, and size was as following: NC-SUV (15.3 +/- 6.9, 8.7 +/- 7.0; P < 0.01), PVC-SUV (18.2 +/- 8.1, 12.7 +/- 7.8; P < 0.05), and size (mm, 32.4 +/- 18.3, 21.9 +/- 10.3; P < 0.05). When an NC-SUV of 9.5 was the cutoff for aggressive NHL, the receiver-operating-characteristic (ROC) analysis correctly identified 21 of 26 aggressive ones. Sensitivity and specificity were 81% each, and the positive and negative predictive values were 88% and 72%, respectively. When a PVCSUV of 11.2 was the cutoff, the ROC analysis revealed 81% sensitivity, 63% specificity, and positive and negative predictive values of 78% and 67%, respectively. At a cutoff for aggressive NHL of a size of 27 mm, the ROC analysis revealed 50% sensitivity, 81% specificity, and positive and negative predictive values of 81% and 50%, respectively. The comparison of area under the curve in ROC analyses indicated that NC-SUV showed the greatest diagnostic accuracy (NC-SUV 0.84, PVC-SUV 0.72, and size 0.69). Diagnostic accuracy of PVC-SUV was inferior to that of NC-SUV. These results suggest that NC-SUV, which contains information on both size and FDG density, provides better differentiation between aggressive and indolent NHLs than PVC-SUV.


Malignant Brenner tumor with transition from benign to malignant components: computed tomographic and magnetic resonance imaging findings with pathological correlation

We report computed tomographic and magnetic resonance findings of an ovarian malignant Brenner tumor with transition from benign to malignant components. The tumor was demonstrated as a cystic mass with solid mural components. The benign component contained dense calcifications on computed tomography and showed very low intensity on T2-weighted images, whereas the malignant component showed high intensity. The admixture of 2 components may well reflect the pathological feature and may be a diagnostic clue to malignant Brenner tumor.


Magnetic Resonance Manifestations of Decidualized Endometriomas During Pregnancy

OBJECTIVE: Decidual changes of endometrial tissue in endometriomas during pregnancy may manifest as mural nodules and mimic malignant transformation. We evaluated magnetic resonance findings of decidualized ovarian endometriomas for the differentiation from malignant transformation. METHODS: Magnetic resonance manifestations of 5 decidualized ovarian endometriomas were evaluated. High b-value diffusion-weighted images were performed in 3 cases. RESULTS: The mural nodules were demonstrated as linear, small nodular, broad-based nodular, or polypoid structures, which showed prominent hyperintensity on T2-weighted images and on diffusion-weighted images similar to normal endometrium or placenta. The apparent diffusion coefficient of decidualized mural nodules was significantly higher than that of malignant mural nodules of 7 ovarian cancers. CONCLUSIONS: Endometrioma with prominent hyperintense mural nodules on T2-weighted images in a pregnant woman is highly suggestive for decidualized endometriomas. Diffusion-weighted images with the apparent diffusion coefficient measurement may help the diagnosis of this rare entity.


FDG-PET/CT findings of autoimmune pancreatitis associated with idiopathic retroperitoneal fibrosis

We report the fluorodeoxyglucose positron emission tomography (FDG-PET)/computed tomography (CT) findings of autoimmune pancreatitis (AIP) associated with idiopathic retroperitoneal fibrosis. A 69-year-old male patient was admitted to our hospital with obstructive jaundice. Six months prior to this admission, he was treated with steroid therapy for retroperitoneal fibrosis. Laboratory data showed that elevated T-bil, C-reactive protein, amylase and immunoglobulin 4, and antinuclear antibodies were positive. Clinical history, laboratory data, CT image, and magnetic resonance imaging led to a diagnosis of autoimmune pancreatitis. To investigate the inflammatory activity, FDG-PET/CT was undertaken. FDG-PET/CT demonstrated diffuse intense FDG uptake in the enlarged pancreas and diffuse mild uptake in the region of the abdominal aorta-bilateral iliac arteries. A dilated right renal pelvis and upper ureter, corresponding to hydronephrosis probably caused by retroperitoneal fibrosis, were shown. An FDG-PET/CT was useful to evaluate inflammatory activity and morphological imaging, and supported our diagnosis of AIP and retroperitoneal fibrosis.


Postprocessing technique with MDCT data improves the accuracy of the detection of lung nodules

The aim of this study was to determine whether postprocessing techniques could improve the accuracy of detecting lung nodules. A total of 154 segmented lung volumes of multidetector-row computed tomography (MDCT) data were the subject of the study. Lung nodules were present in 88 volumes and absent in 66 volumes. We prepared four groups: (1) 7- or 10-mm thick-section axial images; (2) 1-mm thin-section axial images; (3) sliding slab maximum intensity projection (MIP) images with a slab thickness of 15 mm; and (4) sliding slab volume rendering (VR) images with a slab thickness of 15 mm. Sixteen physicians reviewed each group in interactive cine mode. The observers' performance in the detection of lung nodule was evaluated by receiver operating characteristic (ROC) analysis. The observers' performance of the MIP and VR groups was significantly better than in other two groups. There was no significant difference statistically between the thin and thick groups. The detectability of lung nodules is improved with the use of sliding slab MIP and VR using thin-section image data. Thin-section volume data are essential for improving diagnostic accuracy, but observation of thin-section images without utilization of image-processing techniques dose not improve diagnostic accuracy.


Diagnosis of acute stroke patients: using MRI as the first selected modality

MRIを第一選択とした急性期脳血管障害の画像診断法


FDG-PET/CT findings in maxillary lesion.


Utility of FDG-PET/CT examination for patients with cancer of unknown origin.

We reported the utility of18F-FDG-PET/CT examination for patients with cancer of unknownprimary origin. Twenty six patients(13 men, 13 women, aged 27-91 years, mean 71)were examined.The indication for PET/CT examination was tumor maker elevation(14 patients), suspectedmetastatic tumor(14)and metastasis diagnosed histopathologically(3). Patients weretold not to eat for at least four hours and a PET/CT image was obtained one hour after theadministration of 3.7MBq/kg FDG. From April to August 2006, 33 patients diagnosed with a cancerof unknown primary origin were referred to our hospital for PET/CT examination from anoutside institution. Twenty six patients could be investigated for outcomes. Seventeen patientsshowed an abnormal accumulation, with 14 of the 17 having their primary regions detected histopathologicallyor clinically. For one patient, the abnormal accumulation could not be determined toshow the origin. For 2 patients, it was difficult to diagnose if these abnormal accumulationsshowed the primary region or not, but CT examinations were helpful for a diagnosis. Seven of the9 patients who showed no abnormal accumulation were treated conservatively and the primaryregion for their cancer could not be detected during the follow up study. In 21 of 26 patients, theseresults were useful to select an appropriate therapy to be applied or a relevant examination. Weconsidered PET/CT examination, where it is possible to scan the whole body at one time, was veryuseful to get both morphologic and metabolic information. PET/CT examination showed a highersensitivity for detecting abnormal lesions than other imaging modalities.


Radiation therapy for cervical cancer in the elderly

To evaluate the long-term results of radical radiation therapy (RT) for cervical cancer in elderly patients. We reviewed the clinical records of 727 patients with cervical cancer who underwent radical RT at the Tokushima University Hospital and compared the treatment results of three age groups: </=64 years (younger group [YG], 337 patients), 65-74 years (young-old group [YOG], 258 patients), and >/=75 years (older group [OG], 132 patients). At the last follow-up, 155 YG (46%), 77 YOG (30%), and 48 OG patients (36%) had died of cervical cancer; the median follow-up periods were 82, 87, and 68 months, respectively. The 5-/10-year disease-specific survival rates were 60%/52% in YG, 76%/68% in YOG, and 66%/57% in OG. Differences between OG and the other groups were not significant. The 5-/10-year disease-specific survival rate of YOG was significantly superior to that of YG (p<0.001). Clinical stage was the only significant prognostic variable (p<0.001). Late radiation morbidity of grades 2-4 in the bladder and/or rectum occurred in 22% of YG, 31% of YOG, and 8% of OG patients. RT was well tolerated in elderly patients, and age was not a significant prognostic factor. In the management of cervical cancer, advanced age is not a contraindication to radical RT.


FDG-PET/CT for diagnosis and follow-up o f vasculitis.

We report three cases of vasculitis evaluated by FDG-PET/CT. Vasculitis is defined as inflammatory changes and necrosis in the aterial wall. The patients presented with non-specific symptoms such as fever up or elevated inflammatory markers. FDG-PET/CT clearly demonstrated intense FDG uptake in vessel walls. A 72-year-old female patient with a one month history of pyrexia had abnormal laboratory data suggesting an inflammatory process. FDG-PET/CT was very useful for the diagnosis of vasculitis. Steroid therapy was introduced. Normalization of laboratory data and symptomatic improvement correlated with normalization of FDG uptake in the vessels.

The Journal of Medical Investigation : JMI


FDG-PET/CT is increasingly being used for staging, restaging, and treatment monitoring for cancer patients. The introduction of a PET/CT system enables both morphological and metabolic imaging to be performed in a single session. Knowledge of the normal physiologic distribution of FDG and an understanding of the clinical indications and limitations of PET/CT enable accurate diagnosis and thus a better level of care for patients.


Hanging protocol and viewers for a dental full picture [corrected] archiving and communication system (PACS) [corrected].

The new system using a dental DICOM viewer and a dental Web viewer is the most advanced for examining oral and maxillofacial regions compared with medical viewers. Our local but clinically operational hanging protocol should be a good model for DICOM Working Group 22.


SAKURA-viewer: Intelligent order history viewer based on two-viewpoint architecture

We propose a new intelligent order history viewer applied to consolidating and visualizing data. SAKURA-viewer is a highly effective tool, as: 1) it visualizes both the semantic viewpoint and the temporal viewpoint of patient records simultaneously; 2) it promotes awareness of contextual information among the daily data; and 3) it implements patient-centric data entry methods. This viewer contributes to decrease the user's workload in an order entry system. This viewer is now incorporated into an order entry system being run on an experimental basis. We describe the evaluation of this system using results of a user satisfaction survey, analysis of information consolidation within the database, and analysis of the frequency of use of data entry methods.

IEEE Transactions on Information Technology in Biomedicine


The usefulness and problem for MR I examination by using clinical 3T-MRI


Pelvic bone complications following radiation therapy of gynecologic malignancies: clinical evaluation of radiation-induced pelvic insufficiency fractures

To investigate the incidence, clinical and imaging finding of insufficiency fractures (IF) of the female pelvis following radiation therapy. We reviewed the radiation oncology records of 158 patients with gynecologic malignancies who underwent external beam radiation therapy of the whole pelvis between April 1993 and March 2004. All patients underwent computed tomography (CT) scan every 6 months in follow-up after radiation therapy and magnetic resonance imaging (MRI) and radionuclide bone scan were added when the patients complained of a pelvic pain. Eighteen of 158 patients (11.4%) developed IF in the irradiated field with a median interval of 6 months (range 3-51) from the completion of external beam radiation therapy. The cumulative incidence of symptomatic IF at 5 years calculated with Kaplan-Meyer methods was 13%. Median age of the patients who developed IF was 70 years (range 48-88), and all of them were postmenopausal. IF occurred in the sacloiliac joints, upper limb of pubic bone, acetabulum, sacral body and 5th lumbar vertebra. Twelve of 18 patients had multiple lesions and 8 had symmetric longitudinal fracture lines parallel to the sacroiliac joints. Avoidance of weight bearing by bed rest and analgesics provided good pain relief in all patients, although symptoms lasted from 3 to 20 months. Radiation-induced pelvic IF following radiation therapy for gynecologic malignancies were frequently observed in the postmenopausal patients within 1 year after external beam radiation therapy. Symmetric fractures of the both sacroiliac joints were the characteristic pattern of pelvic IF. Knowledge of characteristic imaging pattern of IF is essential in order to rule out the bone metastasis. Therapy recommendations are conservative with analgesics.


Risk factors associated with soft coronary artery plaques in Japanese as determined by 16 slice multidetector-row computed tomography.

The acute coronary syndrome is often caused by the rupture of plaques and thrombus formation even without significant stenosis, and patients with soft plaques, but without significant stenosis evidenced by coronary angiography (CAG), often develop an acute coronary syndrome. To address this discrepancy, a qualitative diagnosis of coronary plaques using a 16 slice multidetector-row CT was conducted. Volume rendering and cross-sectional MPR images were obtained. Based on the CT values, plaques on the coronary artery wall were classified as lipid-rich soft plaques (CT value<50 HU) and non-soft plaques (>50 HU).A significant correlation was observed between the percent stenosis determined in cross-sectional MPR images and those determined by CAG (r=+0.92, p<0.01). Diffuse plaques with CT values of less than 50 HU often caused stenosis at level of 75% or less, which were not indicated by percutaneous transluminal coronary angioplasty. Although diffuse soft plaques with CT values less than 50 HU are not an indication of intervention, a risk of an acute coronary syndrome exists, due to rupture. These soft plaques must be stabilized by treatment even when they do not cause significant stenosis, and MDCT is considered to be useful for their evaluation.


Quality Assurance of I-125 Seed for Prostate Brachytherapy Using an Imaging Plate

OncoSeed is delivered in a sterile environment in the form of a cartridge, so it is impractical to resterilize and reload seeds after calibration. We investigated a new method using an imaging plate dosimetry system to characterize all seeds in the OncoSeed cartridge in a sterile environment. Seeds within the cartridge were placed on an imaging plate, and the imaging plate irradiated. To remove scatter radiation, and improve spatial resolution of seed images, we used X-ray parallel cross grids. The irradiated imaging plate was scanned using a Bio-imaging Analyzer System, and radioactivity intensities of seed images were given in counts. Counts could be translated to profiles, and each seed within the cartridge was analyzed. Results showed a good correlation between counts and total radioactivity of the seeds within the cartridge. Thus, using a least-squares line, it was possible to characterize a cartridge with unknown apparent activity. By analyzing the profiles, it was possible not only to detect a miscalibrated seed in the cartridge from its relative difference in counts, but also to identify its position in the cartridge. No significant changes in counts were seen between sterile and nonsterile environments. Using an imaging plate dosimetry system, all seeds in a cartridge could be characterized in a sterile environment.

International Journal of Radiation Oncology*Biology*Physics


Change of Diffusion Anisotropy in Patients with Acute Cerebral Infarction Using Statistical Parametric Analysis

We conducted statistical parametric comparison of fractional anisotropy (FA) images and quantified FA values to determine whether significant change occurs in the ischemic region. The subjects were 20 patients seen within 24 h after onset of ischemia. For statistical comparison of FA images, a sample FA image was coordinated by the Talairach template, and each FA map was normalized. Statistical comparison was conducted using SPM99. Regions of interest were set in the same region on apparent diffusion coefficient (ADC) and FA maps, the region being consistent with the hyperintense region on diffusion-weighted images (DWIs). The contralateral region was also measured to obtain asymmetry ratios of ADC and FA. Regions with areas of statistical significance on FA images were found only in the white matter of three patients, although the regions were smaller than hyperintense regions on DWIs. The mean ADC and FA ratios were 0.64 +/- 0.16 and 0.93 +/- 0.09, respectively, and the degree of FA change was less than that of the ADC change. Significant change in diffusion anisotropy was limited to the severely infarcted core of the white matter. We believe statistical comparison of FA maps to be useful for detecting different regions of diffusion anisotropy.


Malignant transformation of pelvic endometriosis: MR imaging findings and pathologic correlation

Malignant transformation is a rare complication of endometriosis. Endometriosis-associated ovarian cancers are seen more often in younger women than are ovarian cancers without endometriosis, and early detection is important to improve the prognosis and preserve fertility. However, normal decidual change of the ectopic endometrium in an endometrioma during pregnancy must be differentiated from malignant transformation. The finding that is most important for a diagnosis of malignant change is the presence of one or more contrast material-enhanced mural nodules within a cystic mass at magnetic resonance (MR) imaging. Dynamic subtraction MR imaging is useful in depicting small contrast-enhanced nodules within the hyperintense endometrioma on T1-weighted images. Intracystic coagulate may mimic a mural nodule; the absence of contrast enhancement is the diagnostic clue to its benignity. Enlargement of the endometrioma and the disappearance of shading within the mass on T2-weighted images are suggestive of malignant transformation.


Chemoradiation Therapy for Cervical Cancer:Toxicity of Concurrent Weekly Cisplatio

To retrospectively evaluate the toxicity of concurrent weekly cisplatin and radiation therapy (RT) for locally advanced cervical cancer. Between April 2001 and December 2004, 21 consecutive previously untreated patients with locally advanced cervical cancer were treated with concurrent chemoradiation therapy (CCRT) at the Tokushima University Hospital. Clinical stages were II: 5, III: 15, IVA: 1. External beam radiation therapy (EBRT) was delivered with 10 MV X-rays, 2 Gy fraction per day; total dose to the whole pelvis was 50 Gy. Iridium-192 high-dose-rate (HDR) intracavitary radiation therapy was performed with 10-30 Gy (median, 24 Gy) targeted at point A. Concurrent chemotherapy consisted of cisplatin, administered weekly at a dose of 40 mg/m2 for patients who were younger than 65 years and 30 mg/m2 for those 65 years or over. A maximum single dose of cisplatin, up to 70 mg/body, was administered in 5 cycles during EBRT. A total of 86 cycles of cisplatin were administered to the 21 patients, with a median of 4 cycles (range, 2-5). Severe hematological toxicity occurred in 18 patients (86%), including grade 3 in 17 patients (81%) and grade 4 in one patient (4.8%). Moderate or severe gastrointestinal toxicity occurred in 11 patients (52%), including grade 2 in 10 patients (48%) and grade 3 in one patient (4.8%). The grades of hematological toxicity were significantly greater in the 40 mg/m2 group than in the 30 mg/m2 group. All of the patients who were administered 40 mg/m2 of cisplatin developed grade 3 or greater hematological toxicity, including one patient with grade 4 toxicity. In the 30 mg/m2 group, 3 of 10 patients developed less than grade 3 toxicity, and all patients completed radiation therapy without interruption. The incidence of severe acute hematological toxicity was significantly higher in this study than in previously reported randomized controlled trials (RCTs), especially in the group of 40 mg/m2 cisplatin. A dose of 30 mg/m2 of cisplatin was considered to be feasible in weekly cisplatin and radiation therapy.


Quality Assurance of I-125 Seed Permanent Implant Therapy Using a Self-color Developing Reflection-type Dosimetry Sheet Film

We evaluated a self-color developing sheet-type film for the detection of dead seeds in I-125 permanent implant therapy for prostate cancer. As a preliminary study, we irradiated X-rays to a self-developing reflection-type sheet film and created a relational curve between absorbed dose and film density. I-125 seeds were placed on a film and the approximate absorbed dose of I-125 was calculated from the relational curve of X-rays. A cartridge in which a dead seed was loaded among 10 I-125 seeds was placed on the film and the detectability of the dead seed was evaluated. Using the relational curve of X-rays, it was possible to measure the approximate absorbed dose of I-125 seeds and to easily detect a dead seed at a glance. Using sterilized film, it was possible to detect a dead seed. The self-developing film method is feasible for the detection of a dead seed in a cartridge without re-sterilization of seeds.


The impact of FDG-PET in the management of patients with salivary gland malignancy

The aim of this study was to evaluate the impact of FDG-PET in the management of patients with salivary gland malignancy. We performed 45 FDG PET studies in 31 patients with salivary malignant tumors, using PET (33 studies) and PET/CT (12 studies). Patients comprised 21 males and 10 females with a mean age of 69 y (range 38-89). Nineteen patients had a single study, ten patients had 2 and two patients had 3 studies. Twelve studies were performed for initial staging and 33 studies for restaging. Four patients of the initial staging group were restaged with PET after therapy. Histology consisted of 8 adenocarcinomas, 8 squamous cell carcinomas, 4 adenoid cystic carcinomas, 4 carcinoma ex pleomorphic adenomas, 2 mucoepidermoid carcinomas, 2 poorly differentiated carcinomas, 1 salivary duct carcinoma, 1 lymphoepithelial carcinoma and 1 melanoma. PET findings were reviewed with the clinical and radiologic findings and the impact of PET on staging and patient management was determined. In the initial staging group, all 12 primary lesions (100%) showed positive FDG uptake (5 squamous cell carcinomas, 2 adenocarcinomas, 2 poorly differentiated carcinomas, 1 carcinoma ex pleomorphic adenoma, 1 salivary duct carcinoma, 1 lymphoepithelial carcinoma). Three patients (25%) had FDG positive distant disease (liver, bone, lymph nodes); surgery was canceled and therapy changed to chemoradiation. One patient (9%) with no FDG uptake in the neck nodes avoided a planned neck dissection. In the restaging group (33 studies in 23 patients), 5 patients (22%) had FDG positive distant disease, which changed the treatment from surgery to chemoradiation or other. A second primary lesion was detected in one patient (4%). One patient (4%) with clinically suspected recurrence was able to avoid other invasive procedures because of the negative PET. Overall, FDG PET resulted in a major change in management in 11 of 31 patients (35%). This study shows that FDG PET has a significant impact on the management of patients with salivary malignant tumors in both the initial staging and restaging.


Socio-economical effects of film-less PACS; comparison of pre- and post-film-less operation


Cerebral hyperperfusion in a patient with eclampsia with perfusion-weighted magnetic resonance imaging

The patient was a 25-year-old Japanese woman with postpartum eclampsia, in whom magnetic resonance imaging (MRI) was performed ten hours after convulsion. The patient improved within three days. Diffusion-weighted images showed a high apparent diffusion coefficient (ADC), and perfusion-weighted images obtained by the multi-slice flow-sensitive alternating inversion recovery (FAIR) method showed hyperperfusion, which was suggestive of vasogenic edema, on the parietal and occipital subcortical white matter, corresponding with transient hyperintensities on T2-weighted images. MR angiography (MRA) revealed no signs of vasospasm. These findings suggested hyperperfusion-induced vasogenic edema without cerebrovascular spastic change in the early stage of eclampsia. The FAIR method is considered a useful technique for perfusion-weighted MRI, especially useful to evaluate the cerebral perfusion of emergency patients such as those with eclampsia.


The effect of oral contrast on large bowel activity in FDG-PET/CT.

The purpose of this study was to determine the effect of oral contrast on FDG uptake in the colon and to determine the normal distribution of FDG in the colon. Sixty patients (30 patients in no contrast group and 30 patients in the received contrast group) underwent FDG-PET/ CT scans. The pattern of FDG uptake was classified into 5 patterns (diffuse, segmental, single-nodular, multi-nodular, and other) in 5 segments (ascending, transverse, descending, and rectosigmoid colon). SUVs of the no oral contrast group were examined. The ratios of FDG uptake patterns were compared in the received contrast group and no contrast group to evaluate the effect of oral contast. The effect of attenuation correction on the uptake pattern was evaluated by comparison of the attenuation-corrected and non-attenuation-corrected PET images. In the no contrast group, there was no significant uptake in 72 segments (59%) and a diffuse pattern was seen in 29 segments (24%), most frequently in the ascending colon and descending colon. A segmental pattern was seen in 15 segments (13%), most frequently in the rectosigmoid colon. A single-nodular pattern was seen in 3 segments (3%) and multi-nodular pattern in 1 segment (1%). A nodular pattern was seen only in the ascending colon. SUVmax of the ascending colon and that of the rectosigmoid colon were significantly higher than those of the transverse and descending colon. The frequencies of diffuse, multi-nodular and 'other' patterns were significantly higher in the received contrast group than in no contrast group. There was no significant difference between the frequency of the segmental pattern or the single nodular pattern in the two groups. There was no significant difference between the uptake patterns with attenuation correction and those without attenuation correction in either the received contrast group or no contrast group. Normal FDG uptake in the large bowel may show various degrees and patterns of uptake among the colonic segments. Oral contrast agent can cause focal or diffuse increased FDG uptake, which may be induced not only by the high CT density of oral contrast but also by an accelerated physiologic reaction of the large bowel.


Two cases of retroperitoneal hematoma caused by combination of anticoagulant therapy and 5-fluorouracil

We reported two cases of retroperitoneal hematoma in patients who received a combination of anticoagulant therapy and 5-fluorouracil (5-FU). We should be aware of the possible interaction of this combination therapy and monitor prothrombin time (PT) prolongation. CT is useful for evaluation of the disease.

The Journal of Medical Investigation : JMI


FDG-PET/CT findings of sarcomatous transformation in neurofibromatosis: a case report

We herein report FDG-PET/CT findings of sarcomatous transformation in a patient with neurofibromatosis type 1 (NF-1). About 5% of patients with NF-1 develop sarcomatous transformation of a malignant peripheral nerve sheath tumor which arises from plexiform neurofibromas and is often associated with a poor prognosis. Morphologic imaging techniques such as Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) are the standard methods to define the anatomic extent of the tumor, although tumor heterogeneity prevents reliable differentiation between benign and malignant lesions. The degree of fluoro-deoxyglucose (FDG) uptake correlates with histologic grade in neurogenic tumors in NF-1 patients. Our patient had a huge mass in the left gluteus area with a large nearly circular focus of increased FDG uptake in the tumor. The mass had a photopenic center. The maximum Standard Uptake Value (SUVmax) of this mass was 6.6. There was CT evidence of invasion of the left iliac wing, left acetabulum, and left superior pubic ramus; however there was no increased FDG uptake in these areas on the PET study. We surmised that the high FDG uptake indicated a high grade sarcoma, which was confirmed histologically. There was also a focal region of increased uptake in the L5 vertebral body, correlating with the CT hypodense lesion, with 2.9 SUVmax. FDG-PET/CT can identify sarcomatous change from benign neurogenic tumor with minimal misregistration, and can also detect metastatic disease. This case illustrates the importance of evaluating both metabolic and morphologic abnormalities to be able to formulate a proper treatment plan. This information can be obtained in a single session, using PET/CT.


A case of adenomyomatous polyp of the uterus associated with tamoxifen therapy

A case of adenomyomatous polyp of the uterine endometrium is reported. The patient was 64-year-old woman treated with tamoxifen. Ultrasonography demonstrated a heterogeneous hyperechoic mass with small cystic spaces in the uterus. On magnetic resonance imaging (MRI), a thick stalk with many thin restiform branches within a large solid and cystic endometrial mass showed dendriform low intensity on T2-weighted images and intense enhancement on contrast-enhanced T1-weighted images. The prominent dendriform central fibrous core on MRI reflected a thick stalk originating from the myometrium with numerous branches containing abundant smooth muscle fibers, and may represent the pathologic feature of adenomyomatous polyp.


Pathologies of the uterine endometrial cavity and unusual manifestations and pitfalls on

The endometrial cavity may demonstrate various imaging manifestations such as normal, reactive, inflammatory, and benign and malignant neoplasms. We evaluated usual and unusual magnetic resonance imaging (MRI) findings of the uterine endometrial cavity, and described the diagnostic clues to differential diagnoses. Surgically proven pathologies of the uterine endometrial cavity were evaluated retrospectively with pathologic correlation. The pathologies included benign endometrial neoplasms such as endometrial hyperplasia and polyp, malignant endometrial neoplasms such as endometrial carcinoma and carcinosarcoma, endometrial-myometrial neoplasm such as endometrial stromal sarcoma, pregnancy-related lesions in the endometrial cavity such as gestational trophoblastic diseases (hydatidiform mole, invasive mole and choriocarcinoma) and placental polyp, myometrial lesions simulating endometrial lesions such as submucosal leiomyoma and some adenomyosis, endometrial neoplasms simulating myometrial lesions such as adenomyomatous polyp and endometrial lesions arising in the hemicavity of a septate/bicornate uterus, and fluid collections in the uterine cavity (hydro/hemato/pyometra). It is important to recognize various imaging findings in these diseases, in order to make a correct preoperative diagnosis.


Regional changes of fractional anisotropy with normal aging using statistical parametric mapping (SPM).

There has been reports on the usefulness of diffusion tensor imaging (DTI) about age-or disease-related degradation. DTI is generally evaluated by the region of interest (ROI) methodology. In this study, we applied a statistical way using Statistical Parametric Mapping (SPM) to assess normal aging by DTI and compared results of these two methods. Ten young and ten senior normal volunteers were examined. On SPM, tensor images were changed into normalized tensor images. They were compared between the two groups by t-test. In the senior group, fractional anisotropy (FA) values were higher on the basal ganglia, cingulated gyrus and other cortical gray matter, lower in the corona radiata, internal capsule, centrum semiovale and corpus callosum by using SPM. In the ROI method, the results were almost compatible except in the brain periphery. Aging changes on water diffusion anisotropy was clearly shown by SPM method which would be useful to evaluate change of water diffusion anisotropy without operator bias even in clinical setting instead of ROI measurement.


教育訓練の受講回数とRI使用の有無の教育効果へ与える影響

教育訓練の受講回数とRI使用の有無の教育効果へ与える影響

Japanese Journal of Radiation Safety Management

日本放射線安全管理学会誌


The relationship between standard uptake value (SUV) and Hounsfield Unit (HU) of oral contrast agent for FDG-PET/CT study.

The aim of this study was to examine the relationship between CT density (Hounsfield Unit, HU) and the degree of fluoro-deoxyglucose (FDG) uptake, demonstrated as standard uptake value (SUV). Twenty contiguous patients (9 males, 11 females, age range of 29-79) were performed FDG-PET/CT scan with 750ml of 5% iodine-based oral contrast agent. A region of interest (ROI) was placed manually on oral contrast in the lumen of stomach, small bowel and ascending colon, avoiding contamination of other structures, and the average SUV and average HU were determined. R square and p value were applied to evaluate the correlation. The correlation between SUV and HU in each separate location is not significant. When all regions are combined, p value is significant (<0.05), but R square is not significant. Oral contrast can be one factor that influences measured FDG, and it is possible it acts as an irritant that increases metabolism in the bowel wall, resulting in increased FDG uptake.


Basic study of new diagnostic modality according to non-invasive measurement of the electrical conductivity of tissues

The purposes of this study were to estimate the electrical conductivity of tissues by non-invasively measuring the electrical bio-impedance, to develop a new method for tissue diagnosis, i.e., electrical impedance tomography (EIT). Tissue models were first designed taking into consideration the distribution of the fat tissue, muscle and bone in the human forearm, and then the intra-tissue distributions of electrical potential and field, and the electrical impedance in the models was theoretically analyzed by the three-dimensional finite element method. The electrical impedance of both forearms was measured in healthy human subjects, and estimated the electrical conductivity of individual local tissues. The results of the analysis showed that the distributions of electrical potential and field were affected by the presence of fat tissue but not by the presence or absence of bone. In addition, as a result of calculation of the electrical resistance of the extracellular fluid (Re) in each model, it was found that the value of bio-impedance was influenced by the presence of fat tissue, and the value of bio-impedance was increased by the intervention of a fat layer. The electrical conductivity estimated by fitting the observed values to the values obtained by finite element analysis was 0.40 S/m and 0.15 S/m for male muscle and fat tissue, and 0.35 S/m and 0.11 S/m for female muscle and fat tissue, respectively. The sex difference in the slope of linear approximation in the estimation of electrical conductivity of the males and females was thought to be due to sex differences in the properties and structure of fat tissue. These results suggest that local tissues can be diagnosed differentially and electrically by percutaneous measurement of local bio-impedance and subsequent estimation of the electrical conductivity of each tissue.


Imaging findings of urachal mucinous cystadenocarcinoma associated with pseudomyxoma peritonei.

Pseudomyxoma peritonei is an uncommon neoplastic condition in which gelatinous fluid-like materials are observed in the peritoneal cavity caused by the dissemination of mucinous adenocarcinoma. Although ruptured appendiceal mucocele is the most common cause, tumors arising from other organs may also cause pseudomyxoma peritonei. We report the imaging findings of an extremely rare case of urachal mucinous adenocarcinoma associated with pseudomyxoma peritonei on computed tomography and magnetic resonance imaging with histopathologic correlation.


Difference of signal change by a language task on autistic patients using functional MRI

OBJECTIVE: Cerebral function with a language task was evaluated by functional magnetic resonance imaging (MRI), and the differences of activated pattern and signal changes were compared between autistic patients and normal controls. METHODS: Ten autistic and ten normal subjects were tested by fMRI with a language task requiring the attribution of complex mental states. Activation maps analyzed between two groups were generated and the asymmetry indexes calculated by the quotient of activated pixels of the right frontal lobe divided by those of the left frontal lobe were statistically compared by unpaired t-test. RESULTS: Both the autistic and the normal subjects showed activation at the bilateral prefrontal cortical areas and the ventral occipito-temporal regions. However, the autistic patients demonstrated more activation at the right frontal lobe than the normal controls. Thus it was considered that in the autistic patients the right-hemisphere was more dominant for the language task than that of the normal controls. The result is consist to the theory that autism is related to early left-hemisphere dysfunction. CONCLUSIONS: We considered that fMRI may be a useful non-invasive method to evaluate the cerebral functional abnormality in autistic patients.

The Journal of Medical Investigation : JMI


A case of urachal xanthogranuloma containing a calculus: CT and MRI findings

We report a rare case of an urachal xanthogranuloma containing a urinary calculus, which was considered to have originated from vesicourachal diverticulum. The patient was a 66-year old woman with hematuria and pyuria. Computed tomography (CT) revealed a midline-situated supravesical cavitary mass containing a calculus. Sagittal images of magnetic resonance imaging (MRI) revealed continuity of the mass with the umbilicus. Fatty components of the xanthogranuloma showed low attenuation on CT and hyperintensity on T1-weighted images of MRI. The presence of a large calculus in the vesicourachal diverticulum may have caused continuous irritation resulting in the xanthogranulomatous formation.


Webを用いた放射線業務従事者管理のためのデータ処理ソフトウエアシステムの開発

Webを用いた放射線業務従事者管理のためのデータ処理ソフトウエアシステムの開発

日本放射線安全管理学会誌


Comparison of FAIR technique with different inversion times and post contrast dynamic perfusion MRI in chronic occlusive cerebrovascular disease

The purpose of this study was to examine the signal change occurring with different inversion times (TIs) of the flow-sensitive alternating inversion recovery (FAIR) technique and to compare with the perfusion image obtained with Gd-DTPA injection. The subjects were 11 patients with unilateral occlusive cerebrovascular disease. Two FAIR images with different TIs (800 ms and 1600 ms) were measured for each patient and dynamic perfusion MRI was performed to produce four kinds of parameter maps: mean transit time (MTT), time to peak (TTP), relative cerebral blood flow (rCBF) and relative cerebral blood volume (rCBV) maps. Asymmetry ratios (ARs) between the affected and contra-lateral vascular sides were measured in both FAIR images and the four dynamic parameter maps. The AR of the MTT map of the four parameters showed the highest correlation with that of the FAIR images, especially with that of TI = 1600 ms (r = 0.829), and the AR of the rCBV map revealed the worst correlation with the FAIR images. The AR of the FAIR image with TI = 800 ms was less correlated with that of MTT than that with TI = 1600 ms. These results suggested that the signal intensity of the FAIR image was influenced by flow transition time and the change in TI could be used to select the flow with a different transition time. Our study suggested that a longer TI in the FAIR technique might be more useful than a shorter TI for evaluating chronic occlusive cerebrovascular disease in the clinical setting.


Comparison of washout rate between planar image and polar map image: 123I-BMIPP study.

Myocardial cells obtain 60-90% of their energy from free fatty acids under aerobic conditions. 123I-BMIPP can demonstrate fatty acid metabolism in the myocardium and is used to evaluate cardiac diseases. Forty-three patients underwent BMIPP imaging in the early (15 min) and delayed (4 hr) phase, and the washout rate was calculated. We evaluate the washout rate by two methods, the polar map method and the planar image method. The two methods showed close correlation (r=0.473).


指示データの集約化·視覚化による診療支援システムの開発

指示データの集約化·視覚化による診療支援システムの開発

コンピュータや高速ネットワークの技術進歩を応用した保健医療情報システムの実用化が進んでいる．その中で，院内業務を効率化するシステムや診療に直接貢献するシステムの開発が進められている．診察室においては，生活習慣病などの長期間の診療内容を正確に把握させて効率良い診察を支援するシステムが求められている．本論文では，中小医療機関を対象とした診療支援システムについて述べる．これは，内容的特性と時間的特性の視点から指示データを集約化·視覚かすることで，長期間の指示データの把握や理解を支援し，診療の効率化を図るものである．この集約化は，指示種別ごとの指示項目の組み合わせを基本単位とすることで，指示データの多様性を効率良く表現している．集約化された指示データの視覚化は，指示データの継続性·定期制などの表出を可能にしている．また，指示種別ごとの過去の指示歴や当日の指示などを同一画面で把握できるようにしている．本診療支援システムを中核としてオーダリングシステムを構築して臨床現場で使用し，有効性を医師からのアンケート調査，集約化効果の分析，入力方式の使用頻度調査，データベースアクセス時間の測定により検証した．

The Transactions of the Institute of Electronics, Information and Communication Engineers D-II

電子情報通信学会論文誌(D-II)


Magnetic resonance imaging and proton MR spectroscopy of the brain in a patient with carbohydrate-deficient glycoprotein syndrome type I.

This is a report on a case of carbohydrate-deficient glycoprotein syndrome (CDGS) with neurological deficits. Magnetic resonance (MR) images showed remarkable atrophy of the cerebellum and brainstem, and hypointensity was seen in the pallidum on diffusion-weighted images (DWI), suggesting deposits of metal substances. In the cerebellum, proton MR spectroscopy (MRS) showed decreased concentrations of N-acetylaspartate and a complex of glutamine and glutamate (Glx) while the concentration of myo-inositol was increased, indicating neuronal impairment and gliosis. In the parietal lobe, there was an increased concentration of Glx, possibly reflecting dysfunction caused by liver injury.

Journal of Magnetic Resonance Imaging : JMRI


Patient Skin Dose in Interventional Radiology Using Radiochromic Dosimetry Film

反射型線量測定用フィルムを用いたIVR手技時の患者皮膚線量

照射部位が多彩で，X線管-皮膚間距離が不定なIVR手技に対してX線照射により直ちに発色する感材で作られた低感度の反射型フィルムを用いた被曝線量測定について検討した結果，良好な結果が得られたので報告した．

Japanese Journal of Radiological Technology


Magnetic resonance imaging and spectroscopy in a patient with treated methylmalonic acidemia.

Magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy (proton MRS) findings before and after carnitine therapy in a patient with methylmalonic acidemia (MMA) are evaluated. The hyperintensity on T2-weighted image and diffusion-weighted image and the decreased apparent diffusion coefficient of bilateral basal ganglia were normalized in parallel with normalization of the elevated lactate levels and the decreased N-acetyl-aspartate levels, corresponding to improvement of clinical symptoms. MRI and proton MRS may serve as a suitable, noninvasive modality for monitoring treated MMA.


Localized pseudomyxoma peritonei in the female pelvis simulating ovarian carcinomatous peritonitis.

Two cases of localized pseudomyxoma peritonei in the female pelvic cavity associated with a ruptured appendiceal mucocele and ovarian involvement that mimicked ovarian carcinomatous peritonitis were evaluated. Subtle omental irregularity adjacent to the cecum may suggest the hidden appendiceal origin reflecting localized carcinomatous peritonitis caused by the occult rupture of the mucocele. Mucinous fluid-like materials were localized in the pelvic cavity with scalloping of the uterus, which may be the diagnostic finding of pseudomyxoma peritonei.


Ovarian cystadenofibromas: characteristic magnetic resonance findings with pathologic correlation

Ovarian cystadenofibroma is a benign tumor and may appear as a multilocular cystic mass with solid nodular components mimicking malignant ovarian tumor. Preoperative diagnosis is required to avoid excess surgical procedure. We report characteristic magnetic resonance imaging (MRI) findings of 2 cases with pathologic correlation. On T2-weighted images, the solid components of the tumors showed very low intensity, in which very high intense tiny cysts were present reflecting dense fibrous stromal proliferation with scattered small cystic glandular structures. This "black sponge"-like appearance was considered to be diagnostic.