Yuka Hiroshima, Youichi Otomi, Takayoshi Shinya, Hideki Otsuka and Masafumi Harada : F-FDG PET/CT in the Evaluation of Adult Alveolar Rhabdomyosarcoma., Molecular Imaging and Radionuclide Therapy, Vol.32, No.1, 62-64, 2023.
(Summary)
C-methionine PET/CT for accurately assessing the extent of alveolar rhabdomyosarcoma, especially in cases with intracranial infiltration or those approximating the brain.
Takayoshi Shinya, Tomoki MATSUSHITA, Yuka HIROSHIMA, Youichi Otomi, Yasuhisa Kanematsu, Yoshimi Bando, Hisanori Uehara, Yoshiaki Kitamura and Masafumi Harada : Imaging features of a myoepithelial carcinoma of the nasal cavity: A case report and literature review, Radiology Case Reports, Vol.18, No.1, 386-391, 2022.
(Summary)
Myoepithelial carcinoma of the nasal cavity is extremely rare. We report the case of a 66-year-old man with myoepithelial carcinoma of the nasal cavity. Computed tomography (CT) and magnetic resonance imaging revealed a lobulated soft tissue mass with central necrosis and hemorrhage, as well as an invasion of the skull base and left orbit. The patient presented with continuous nasal congestion and heavy head and had no elevated level of squamous cell carcinoma-related antigen. CT, magnetic resonance imaging, or F-fluorodeoxyglucose (FDG) positron emission tomography/CT revealed no evidence of a metastatic lesion. F-FDG accumulation in the tumor was inhomogeneous and moderate. Histopathological examination of the resected specimen confirmed a well-circumscribed solid tumor with septa, a small area of hemorrhage, and necrosis. The subsequent diagnosis was a myoepithelial carcinoma of the left nasal cavity. This case shows that nasal myoepithelial carcinoma might appear as a well-defined lobulated mass with hemorrhagic necrosis and intense contrast enhancement in the solid component. We conjecture that hemorrhagic necrosis and intense enhancement values may be potential markers of nasal myoepithelial carcinoma.
M Chuluunbat, D Matsuda, Koji Fujita, M Otomo, Youichi Otomi, K Kudo, Masafumi Harada and Yuishin Izumi : Identification and validation of a gray matter volume network in Alzheimer's disease, Journal of the Neurological Sciences, Vol.440, 120344, 2022.
(Summary)
This study aims to identify and validate a gray matter volume network in patients with Alzheimer's disease (AD). To identify a disease-related network, a principal component analysis-based algorithm, Scaled Subprofile Model, was applied to gray matter volume data derived from structural T1-weighted magnetic resonance imaging of the training sample that consisted of nine patients with AD (women, four; dementia, seven; mild cognitive impairment, two; age, 66.7 ± 8.8 [mean ± SD] years) with positive F-flutemetamol amyloid positron emission tomography and eight age-matched healthy controls obtained on-site. The network expression scores were calculated by topographic profile rating in the validation sample obtained via the Open Access Series of Imaging Studies and comprised 12 patients with AD dementia (women, four; age, 70.0 ± 3.7 years) and 12 age-matched healthy controls. A significant network from the training sample, for which subject expression differed between the groups (permutation test, P = 0.006; sensitivity and specificity, 100%; area under the curve, 1), was identified. This network was represented by the principal components 1, 2, and 3 and showed a relative decrease in the inferior parietal lobule including angular gyrus, inferior temporal gyrus, premotor cortex, amygdala, hippocampus, and precuneus. It significantly differed between the groups with a sensitivity, specificity, and area under the curve of 83%, 91%, and 0.85, respectively, in the validation sample (P = 0.003). An AD-related gray matter volume network that captured relevant regions was identified in amyloid positron emission tomography-positive patients and validated in an independent sample.
Youichi Otomi, Saho Irahara, Hiroaki Inoue, Takayoshi Shinya, Hideki Otsuka and Masafumi Harada : Increased 18F-FDG Uptake in the Axillary Lymph Nodes of Vaccinated Side Associated with COVID-19 Vaccination, Molecular Imaging and Radionuclide Therapy, Vol.31, No.2, 169-171, 2022.
(Summary)
A 50-year-old female patient underwent (fluorine-fluorodeoxyglucose (F-FDG) positron emission tomography/computed tomography (PET/CT) following modified radical mastectomy for cancer of the left breast. Ten days before the PET/CT, the coronavirus disease-2019 (COVID-19) vaccine was injected intramuscularly into the right deltoid muscle. Increased (F-FDG uptake of maximum standardized uptake value (11.0) was observed in the lymph nodes of the right axilla, which had not been observed in the previous PET/CT. The size of the oval-shaped lymph nodes was up to approximately 11×9 mm; however, it was larger than that observed on the previous PET/CT. We contemplate that the increased (F-FDG uptake was a reactive change in the lymph nodes associated with the COVID-19 vaccine.
Nahomi Shono, Youichi Otomi, Hideki Otsuka, Takayoshi Shinya and Masafumi Harada : Multicystic Biliary Hamartoma With Xanthogranulomatous Inflammation on 18F-FDG PET/CT., Clinical Nuclear Medicine, Vol.47, No.10, 882-884, 2022.
(Summary)
A 70-year-old man with a liver tumor was pathologically diagnosed with multicystic biliary hamartoma with xanthogranulomatous inflammation. Plain CT revealed an inhomogeneous low-density liver tumor, measuring 43 × 35 mm. Dynamic contrast-enhanced CT revealed a cyst, measuring approximately 15 mm, with a ring-shaped enhancement, within the tumor. There was delayed enhancement on the outer portion of the tumor. Mild peripheral bile duct dilation was also observed. 18F-FDG PET/CT showed focal high uptake with an SUVmax of 5.2 near the cyst. The findings of this case mimicked that of intrahepatic cholangiocellular carcinoma.
Youichi Otomi, Yuta Arai, Maki Ohtomo, Saho Irahara, Kaori Terazawa, Michiko Kubo, Takashi Abe, Takayoshi Shinya, Hideki Otsuka and Masafumi Harada : Increased physiological [18F] FDG uptake in the liver and blood pool among patients with impaired renal function, Nuclear Medicine Review. Central & Eastern Europe, Vol.25, No.2, 95-100, 2022.
(Summary)
In the daily clinical course, the liver uptake may seem to be increased in patients with renal failure. The purpose of this study was to investigate whether or not the FDG uptake of the liver, and the FDG uptake of blood pool which is generally used as a reference site as well as liver, is increased in patients with renal failure. We retrospectively analyzed 233 patients who underwent FDG positron emission tomography/computed tomography (PET/CT). Renal failure is defined as an estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2. We compared the FDG uptake in the liver and mediastinal blood pool of 67 patients with impaired renal function to that in 166 patients with a normal renal function (eGFR ≥ 60 mL/min/1.73 m2). Correlations between the liver or mediastinal blood pool FDG uptake and the eGFR were also analyzed by Spearman's correlation test. Maximum and mean standardized uptake values (SUVmax and SUVmean, respectively) of the liver and the SUVmean of the mediastinal blood pool were 3.48 ± 0.57, 2.56 ± 0.37, and 1.90 ± 0.28 in the impaired renal function group, respectively, and 3.13 ± 0.45, 2.29 ± 0.33, and 1.66 ± 0.23, in the normal group, respectively. The SUVmax and SUVmean of the liver and SUVmean of the mediastinal blood pool in the impaired renal function group were significantly higher than those in the normal group (p < 0.001, < 0.001, and < 0.001, respectively). The SUVmax and SUVmean of the liver and SUVmean of the mediastinal blood pool of patients showed a significant negative correlation with the eGFR (Spearman's p = -0.25, -0.30, and -0.40, respectively, each p < 0.001). FDG uptake in both the liver and mediastinal blood pool was higher in patients with impaired renal function.
Moriaki Yamanaka, Shoichiro Takao, Hideki Otsuka, Youichi Otomi, Saho Irahara, Yamato Kunikane, Satoru Takashi, Airi Yamamoto, Masataka Sata and Masafumi Harada : The Utility of a Combination of <sup>99m</sup>Tc-MIBI Washout Imaging and Cardiac Magnetic Resonance Imaging in the Evaluation of Cardiomyopathy, Annals of Nuclear Cardiology, Vol.7, No.1, 8-16, 2021.
(Summary)
Background: In cardiomyopathy, 99mTc-MIBI washout can reflect mitochondrial dysfunction and late gadolinium enhancement (LGE) on cardiac magnetic imaging (MRI) is associated with tissue fibrosis. We sought to determine the relationship between 99mTc-MIBI uptake, 99mTc-MIBI washout, and LGE on MRI in patients with cardiomyopathy. Methods: Twenty-one patients underwent rest myocardial perfusion scintigraphy at 45 minutes (early) and 4 hours (delayed) after intravenous 99mTc-MIBI administration and cardiac MRI. We assessed myocardial perfusion, 99mTc-MIBI washout, and LGE. We divided the left ventricle (LV) wall into 16 segments using a polar map. Then, we classified each segment into 5 groups according to 99mTc-MIBI uptake in early-rest images and washout. Additionally, we created a contingency table based on LGE presence/absence in the groups. Results: We evaluated 336 segments in 21 patients. 99mTc-MIBI uptake was decreased in 168 segments in the early-rest 99mTc-MIBI images. 99mTc-MIBI washout was observed in 108 segments with either normal perfusion or reduced perfusion in the early-rest 99mTc-MIBI images. LGE was positive in 104 segments. A contingency table analysis with Fisher窶冱 exact test showed that LGE was observed significantly more frequently in the segments with decreased 99mTc-MIBI uptake (p < 0.001). In segments without a decreased 99mTc-MIBI uptake, there was a significant correlation between increased 99mTc-MIBI washout and the presence of LGE (p = 0.033). Conclusions: In cardiomyopathy, the mitochondrial dysfunction in the early stage is shown as 99mTc-MIBI washout, and fibrotic changes in the myocardium in advanced stages are shown as LGE on cardiac MRI. The severity of myocardial damage and the clinical stage of cardiomyopathy can be evaluated using multimodal imaging.
(Keyword)
<sup>99m</sup>Tc-MIBI / Cardiomyopathy / Late gadolinium enhancement (LGE) / Washout
Youichi Otomi, Nahomi Shono, Hajime Onishi, Ryota Mitsuhashi, Saya Matsuzaki, Yukiko Takaoka, Hideaki Enomoto, Yuko Sakamoto, Mihoko Sasahara, Takashi Abe, Takayoshi Shinya, Hideki Otsuka and Masafumi Harada : A reduced physiological 18 F-fluorodeoxyglucose uptake in the brain and liver caused by malignant lymphoma being deprived of the tracer, The Journal of Medical Investigation : JMI, Vol.68, No.1. 2, 181-185, 2021.
(Summary)
Purpose : To investigate whether or not the physiological brain and liver FDG uptake are decreased in patients with highly accelerated glycolysis lesions. Methods : We retrospectively analyzed 51 patients with malignant lymphoma. We compared the FDG uptake in the brain and liver of the patients with that in a control group. In 24 patients with a complete response (CR) or partial response (PR) to treatment, we compared the brain and liver uptake before and after treatment. Results : The maximum standardized uptake value (SUVmax) and total glycolytic volume (TGV) of the brain as well as the SUVmax and mean standardized uptake value (SUVmean) of the liver in malignant lymphoma patients were 13.1 ± 2.3, 7386.3 ± 1918.4, 3.2 ± 0.5, and 2.3 ± 0.4, respectively ; in the control group, these values were 14.9 ± 2.4, 8566.2 ± 1659.5, 3.4 ± 0.4, and 2.5 ± 0.3, respectively. The SUVmax and TGV of the brain and the SUVmean of the liver in malignant lymphoma patients were significantly lower than the control group. The SUVmax and TGV of the brain after treatment were significantly higher than before treatment. Both the SUVmax and SUVmean of liver after treatment were higher than before treatment, but not significant. Conclusion : A decreased physiological brain and liver FDG uptake is caused by highly accelerated lesion glycolysis. J. Med. Invest. 68 : 181-185, February, 2021.
Takayoshi Shinya, Youichi Otomi, Toshihiko Nishisho, Bettina Beuthien-Baumann, Michiko Kubo, Hideki Otsuka, Yoshimi Bando, Hiroaki Yanagawa, Koichi Sairyo and Masafumi Harada : Preliminary clinical assessment of dynamic carbon-11 methionine positron-emission tomography/computed tomography for the diagnosis of the pathologies in patients with musculoskeletal lesions: a prospective study., European Journal of Hybrid Imaging, Vol.26, No.4, 15, 2020.
(Summary)
Dynamic C-11 MET PET scans have the potential to be good predictors of discriminating MSLs in patients with primary unknown MSLs in clinical practice.
Hozumi Yoshihara, Hidehiko Hosoki, Midori Yoshida, Yoshio Kume, Youichi Otomi, Masafumi Amano, Masao Yuasa, Kenji Yamada, Hideki Suito, Naoki Maeda, Naonobu Kawata, Masafumi Harada and Eiichi Honda : Changes in Image Examinations at the Department of Oral Radiology -The Number of Intraoral and Panoramic Radiographs-, Journal of Oral Health and Biosciences, Vol.32, No.1, 1-9, 2019.
(Summary)
After the computed radiography (CR) system was developed in 1986, it became possible to acquire, view and save digital images for medical diagnosis. Around that time, panoramic radiography was digitized by the CR system, but it was limited to large hospitals. From 1994, it has been digitized at large hospitals and dental clinics. We examined the changes in the number of intraoral and panoramic radiographs in dentistry, and based on the relationships among the numbers of radiographs, patients and dental operations, we discussed the clinical significance of digitization.<br>We extracted intraoral and panoramic radiography data, the number of dental operations and the number of patients from the database of Tokushima University Hospital from 2002 to 2017. Then, we extracted nationwide data from Statistics of Medical Care Activities in Public Health by the Ministry of Health, Labour and Welfare from 2002 to 2017.<br>As a result, although the numbers of patients and dental operations at Tokushima UniversityHospital have remained constant, the number of intraoral radiographs has decreased (72%), whereas the number of panoramic radiographs has increased annually since 2011 (131%). In addition, although the number of patients and nationwide insurance points increased in a different manner than that at Tokushima University Hospital, a decrease in the number of intraoral radiographs and an increase in the number of panoramic radiographs were noted across Japan. As panoramic imaging has been improved and adapted to different settings, panoramic radiography has been used instead of intraoral radiography, and it has been widely used in screening applications such as for perioperative patients. Although digitization is progressing, the analog images are still used (intraoral radiography analog rate, 29.7%, panoramic radiography analog rate, 12.4% in 2017).
Youichi Otomi, Hideki Otsuka, Kaori Terazawa, Moriaki Yamanaka, Yuki Obama, Maki Arase, Maki Otomo, Saho Irahara, Michiko Kubo, Naoto Uyama, Takashi Abe and Masafumi Harada : The diagnostic ability of SPECT/CT fusion imaging for gastrointestinal bleeding: a retrospective study., BMC Gastroenterology, Vol.18, No.1, 183, 2018.
(Summary)
Blood loss from the gastrointestinal tract can be an acute and life-threatening event. For the treatment of gastrointestinal bleeding, it is important to accurately detect gastrointestinal bleeding and to localize the sites of bleeding. The purpose of this study was to retrospectively assess the capabilities of SPECT/CT in the diagnosis of gastrointestinal bleeding by a comparison with planar imaging alone as well as planar and SPECT. We conducted a retrospective analysis of 20 patients (21 examinations) who underwent gastrointestinal bleeding scintigraphy in the past 7ears and in whom the bleeding site was identified by endoscopy or capsule endoscopy, or in whom no evidence of gastrointestinal bleeding was identified during the clinical course. Five patients (5 examinations) were diagnosed by planar imaging (planar group). Eight patients (9 examinations) were diagnosed by planar imaging and SPECT (planar + SPECT group). Seven patients (7 examinations) were diagnosed by planar imaging and SPECT/CT (planar + SPECT/CT group). We calculated the diagnostic ability of each method in detecting the presence of bleeding, as well as the ability of each method to identify the sites of bleeding. The sensitivity, specificity, and accuracy of the methods were compared. The diagnostic ability of the three imaging methods in detecting the presence of gastrointestinal bleeding was as follows. Planar imaging showed 100% sensitivity (3/3), 100% specificity (2/2), and 100% accuracy (5/5). Planar + SPECT imaging showed 85.7% sensitivity (6/7), 100% specificity (2/2), and 88.9% accuracy (8/9). Planar + SPECT/CT imaging showed 100% sensitivity (6/6), 100% specificity (1/1), and 100% accuracy (7/7). The diagnostic ability of the three modalities in detecting the site of bleeding was as follows: planar, 33.3% (1/3); planar + SPECT, 71.4% (5/7); and planar + SPECT/CT, 100% (6/6). All 3 imaging methods showed good accuracy in detecting the presence of gastrointestinal bleeding. The addition of SPECT or SPECT/CT made the anatomical position of the uptake clear and contributed to the localization of the site of gastrointestinal bleeding. Planar + SPECT/CT imaging therefore showed the highest diagnostic ability for detecting the site of gastrointestinal bleeding.
Naoto Uyama, Hideki Otsuka, Takayoshi Shinya, Youichi Otomi, Masafumi Harada, Wataru Sako, Yuishin Izumi, Ryuji Kaji, Yuya Watanabe, Satoru Takashi and Yamato Kunikane : The utility of the combination of a SPECT study with [123I]-FP-CIT of dopamine transporters and [123I]-MIBG myocardial scintigraphy in differentiating Parkinson disease from other degenerative parkinsonian syndromes., Nuclear Medicine Communications, Vol.38, No.6, 487-492, 2017.
(Summary)
Molecular imaging of nigrostriatal dopamine transporters (DAT) and sympathetic cardiac innervation with single-photon emission computed tomography (SPECT) are useful tools for differentiating idiopathic Parkinson disease (PD) from other degenerative parkinsonian syndromes (non-PD). Nevertheless, these modalities are often insufficient for achieving a definite diagnosis. The aims of this study were to evaluate the diagnostic accuracy of the combination of these tools. The SPECT radiotracers [I]-N-ω-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl)-nortropane (FP-CIT) and meta-[I]-iodobenzylguanidine (MIBG) were used to research presynaptic dopaminergic projections (DAT SPECT) and myocardial adrenergic innervation (MIBG scintigraphy), respectively. PD patients (n=15; age: 61.5±13.6 years) and non-PD patients (n=19; age: 62.6±14.2 years) who underwent both tests were enrolled in this study. Receiver-operating characteristic analyses were used to set the cutoff values of the specific binding ratio in DAT SPECT and the heart to mediastinum ratio in delayed scan in MIBG scintigraphy for differentiating PD from non-PD. We calculated the sensitivity, specificity, and test accuracy of the individual methods and also the combination of these two modalities. When DAT SPECT and MIBG scintigraphy were used individually, they showed mild accuracy in differentiating PD from non-PD (DAT, 67.6%; MIBG, 67.6%). The combination of the two approaches using cutoff values of less than 3.24 for the specific binding ratio and less than 2.745 for the delayed heart to mediastinum ratio enabled more accurate differentiation between PD and non-PD. The accuracy of these indices in distinguishing PD from non-PD was 79.4%. These results suggested that the combination of DAT SPECT and MIBG scintigraphy may improve the diagnostic accuracy in differentiating PD from non-PD.
Delgerdalai Khashbat, Takashi Abe, Mungunbagana Ganbold, Seiji Iwamoto, Naoto Uyama, Saho Irahara, Youichi Otomi, Masafumi Harada, Teruyoshi Kageji and Shinji Nagahiro : Correlation of 3D Arterial Spin Labeling and Multi-Parametric Dynamic Susceptibility Contrast Perfusion MRI in Brain Tumors., The Journal of Medical Investigation : JMI, Vol.63, No.3-4, 175-181, 2016.
(Summary)
Arterial spin labeling (ASL) is an alternative method to Dynamic susceptibility contrast (DSC) perfusion MRI for brain tumors. However, ASL cerebral blood flow (CBF) can be easily affected by transit time. DSC MRI derived time to maximum of the residue function (Tmax) is possible to assess the transit time on ASL. Thirty patients with brain tumors were studied using ASL and DSC MRI. The relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), Tmax, and mean transit time (MTT) were obtained from DSC MRI. The ratios of the parameters were analyzed. ASL CBF ratio correlated with the DSC rCBF ratio (r=0.78, p<0.001) and rCBV ratio (r=0.74, p<0.001). There was a moderate correlation between ASL CBF ratio and Tmax ratio (r=-0.43, p<0.05) in brain tumors. ASL CBF strongly correlated with DSC rCBF and rCBV. In addition, a negative correlation was found between ASL CBF and Tmax in brain tumors, indicating that these parameters would be affected by transit time. This may explain why ASL CBF is different from DSC rCBF and rCBV. The decreased DSC Tmax value may suggest high vascularity in a tumor. J. Med. Invest. 63: 175-181, August, 2016.
Youichi Otomi, Takayoshi Shinya, Hideki Otsuka, Terazawa Kaori, Irahara Saho, Nagase Saki, Takahashi Ayaka, Michiko Kubo and Masafumi Harada : Increased (18)F-fluorodeoxyglucose accumulation in bilateral adrenal glands of the patients suffering from vasovagal reaction due to blood vessel puncture., Annals of Nuclear Medicine, Vol.30, No.7, 501-505, 2016.
(Summary)
The purpose of the study was to evaluate the hypothesis that patients having a vasovagal reaction (VVR) after blood vessel puncture show increased FDG accumulation in bilateral adrenal glands. Over the past 8 years, 26 patients experienced a VVR after blood vessel puncture following intra-venous injection of FDG at our institution. Of the 26 patients, 16 underwent multiple-occasion FDG-PET/CT scans while suffering a VVR at only one examination. All 16 patients had no morphological abnormality in the adrenal glands on FDG-PET/CT and follow-up examination. For the 16, we retrospectively reviewed the FDG-PET/CT scan with respect to the adrenal glands and compared the result to that for the FDG-PET/CT scan of the same patient when there was no VVR event. We used both visual analysis and semi-quantitative analysis employing either maximum standardized uptake value (SUVmax) or adrenal-to-liver (A/L) SUVmax ratio. On visual analysis of the FDG-PET/CT with VVR, accumulations in both of the adrenal glands was judged positive, defined as higher than the hepatic accumulation, in 84 % of the cases. The SUVmax in the right adrenal gland was 2.79 ± 0.69 with VVR and 1.92 ± 0.33 without VVR; this value in the left adrenal gland was 3.07 ± 0.71 with VVR and 2.05 ± 0.39 without. Mean SUVmax of both adrenal glands was 2.93 ± 0.66 with VVR and 1.98 ± 0.35 without. The A/L SUVmax ratio in the right adrenal gland was 1.02 ± 0.26 with VVR and 0.69 ± 0.11 without; this value in the left was 1.11 ± 0.23 with VVR and 0.74 ± 0.15 without. The mean A/L SUVmax ratio of both adrenal glands was 1.06 ± 0.24 with VVR and 0.72 ± 0.13 without. Each parameter with VVR was significantly higher than that without. For the two adrenal glands, the mean SUVmax with VVR was 48 % higher than that without VVR. We confirmed the hypothesis that patients having a VVR after blood vessel puncture show increased FDG accumulation in their bilateral adrenal glands. This may reflect hyper-metabolism of the adrenal glands in synthesizing and secreting catecholamine.
Mungunkhuyag Majigsuren, Takashi Abe, Teruyoshi Kageji, Kazuhito Matsuzaki, Mayumi Takeuchi, Seiji Iwamoto, Youichi Otomi, Naoto Uyama, Shinji Nagahiro and Masafumi Harada : Comparison of brain tumor contrast-enhancement on T1-CUBE and 3D-SPGR images, Magnetic Resonance in Medical Sciences, Vol.15, No.1, 34-40, 2016.
(Summary)
T1-Cube (GE HealthCare) is a relatively new 3-dimensional (3D) fast spin-echo (FSE)-based magnetic resonance (MR) imaging sequence that uses a variable flip angle to acquire gap-free volume scans. We compared the gadolinium enhancement characteristics of a heterogeneous population of brain tumors imaged by T1-Cube and then 3D fast spoiled gradient recall acquisition in steady state (3D FSPGR) 3-tesla MR imaging to identify the superior modality for specific diagnostic purposes. We examined 61 lesions from 32 patients using the 2 sequences after administration of gadopentetic acid (Gd-DTPA; 0.1 mmol/kg). Two neuroradiologists independently measured each lesion twice using a region-of-interest (ROI) method. We measured the contrast-to-noise ratio (CNR), the difference in signal intensity (SI) between the tumor and normal white matter relative to the standard deviation (SD) of the SI within the lesion, for both post-contrast 3D FSPGR and post-contrast T1-Cube images of the same tumor and compared modality-specific CNRs for all tumors and in subgroups defined by tumor size, enhancement ratio, and histopathology. The mean CNR was significantly higher on T1-Cube images than 3D FSPGR images for the total tumor population (1.85 ± 0.97 versus 1.12 ± 1.05, P < 0.01) and the histologic types, i.e., metastasis (P < 0.01) and lymphoma (P < 0.05). The difference in CNR was even larger for smaller tumors in the metastatic group (4.95 to 23.5 mm(2)) (P < 0.01). In contrast, mean CNRs did not differ between modalities for high grade glioma and meningioma. Gadolinium enhancement of brain tumors was generally higher when imaged by T1-Cube than 3D FSPGR, and T1-Cube with Gd enhancement may be superior to 3D FSPGR for detecting smaller metastatic tumors.
(Keyword)
Adult / Aged / Aged, 80 and over / Astrocytoma / Brain Neoplasms / Contrast Media / Female / Gadolinium DTPA / Humans / Image Enhancement / Image Processing, Computer-Assisted / Imaging, Three-Dimensional / Lymphoma, Large B-Cell, Diffuse / magnetic resonance imaging / Male / Meningioma / Middle Aged / Oligodendroglioma / Signal-To-Noise Ratio / White Matter
Takashi Abe, Yoshifumi Mizobuchi, Kohhei Nakajima, Youichi Otomi, Saho Irahara, Yuki Obama, Mungunkhuyag Majigsuren, Delgerdalai Khashbat, Teruyoshi Kageji, Shinji Nagahiro and Masafumi Harada : Diagnosis of brain tumors using dynamic contrast-enhanced perfusion imaging with a short acquisition time, SpringerPlus, Vol.24, No.4, 88, 2015.
(Summary)
This study sought to determine the diagnostic utility of perfusion parameters derived from dynamic contrast-enhanced (DCE) perfusion MRI with a short acquisition time (approximately 3.5 min) in patients with glioma, brain metastasis, and primary CNS lymphoma (PCNSL). Twenty-six patients with 29 lesions (4 low-grade glioma, 13 high-grade glioma, 7 metastasis, and 5 PCNSL) underwent DCE-MRI in a 3 T scanner. A ROI was placed on the hotspot of each tumor in maps for volume transfer contrast K (trans) , extravascular extracellular volume V e , and fractional plasma volume V p . We analyzed differences in parameters between tumors using the Mann-Whitney U test. We calculated sensitivity and specificity using receiver operating characteristics analysis. Mean K (trans) values of LGG, HGG, metastasis and PCNSL were 0.034, 0.31, 0.38, 0.44, respectively. Mean Ve values of each tumors was 0.036, 0.57, 0.47, 0.96, and mean Vp value of each tumors was 0.070, 0.086, 0.26, 0.17, respectively. Compared with other tumor types, low-grade glioma showed lower K (trans) (P < 0.01, sensitivity = 88%, specificity = 100%) and lower V e (P < 0.01, sensitivity = 96%, specificity = 100%). PCNSL showed higher V e (P < 0.01, sensitivity = 100%, specificity = 88%), but the other perfusion parameters overlapped with those of different histology. Kinetic parameters derived from DCE-MRI with short acquisition time provide useful information for the differential diagnosis of brain tumors.
Youichi Otomi, Hideki Otsuka, Kaori Terazawa, Hayato Nose, Michiko Kubo, Kenji Matsuzaki, Hitoshi Ikushima, Yoshimi Bando and Masafumi Harada : Comparing the performance of visual estimation and standard uptake value of F-18 fluorodeoxyglucose positron emission tomography/computed tomography for detecting malignancy in pancreatic tumors other than invasive ductal carcinoma., The Journal of Medical Investigation : JMI, Vol.61, No.1-2, 171-179, 2014.
(Summary)
The utility of FDG PET/CT for the detection and evaluation of invasive ductal carcinoma has been widely reported, but a few studies have assessed the utility of FDG PET/CT to detect malignancy in a variety of pancreatic lesions other than invasive ductal carcinoma. To compare the diagnostic performance of visual estimation with the semi-quantitative scores of FDG PET/CT for detecting malignancy in a variety of pancreatic lesions other than invasive ductal carcinoma. Images of pathologically proven pancreatic lesions from 32 patients were retrospectively evaluated: 14 benign lesions, 7 borderline (low malignant) lesions, and 11 malignant lesions. The average scores from visual estimation by the two observers were compared to two semi-quantitative analyses of FDG uptake in the lesions, namely the maximum standardized uptake value (SUVmax) and mean standardized uptake value (SUVmean). Visual analysis value, SUVmax and SUVmean were 0.33 ± 0.21, 1.8 ± 0.7 and 1.5 ± 0.7 for the benign lesions, 0.70 ± 0.28, 5.0 ± 2.6 and 3.1±1.7 for the borderline lesions, and 0.73 ± 0.18, 4.7 ± 2.5 and 3.2 ± 1.6 for the malignant lesions, respectively. Receiver operating characteristic analysis revealed the areas under the curves for detecting non-benign (malignant or borderline) lesions through visual analysis, SUVmax, and SUVmean were 0.914, 0.954, and 0.875, respectively. For a variety of pancreatic lesions other than invasive ductal carcinoma, visual analysis and semi-quantitative analyses all showed strong diagnostic performance. However, semi-quantitative analysis with SUVmax proved to be the most effective method for detecting non-benign pancreatic lesions.
Hayato Nose, Hideki Otsuka, Youichi Otomi, K Terazawa, Shoichiro Takao, Seiji Iwamoto, Takashi Iwase, Hirotsugu Yamada, Masataka Sata and Masafumi Harada : The physiological uptake pattern of (18)F-FDG in the left ventricular myocardium of patients without heart disease., The Journal of Medical Investigation : JMI, Vol.61, No.1, 2, 53-58, 2014.
(Summary)
Purpose: The purpose of this study was to evaluate the physiological uptake pattern of 18F-FDG in the left ventricular myocardium of patients under preparation for tumor FDG-PET. Patients and Methods: We enrolled 188 patients without cardiac disease. The accumulation patterns were classified as either none, diffuse, focal or focal on diffuse. When a focal uptake was only observed on the basal wall, then the patterns were classified as having either a ring, over half or spot uptake. Results: The frequencies of the myocardial FDG uptake patterns were as follows: none, n=52 (27.7%); diffuse, n=63 (33.5%); focal on diffuse, n=40 (21.3%) and focal, n=33 (17.6%). The age, blood glucose level, weight and dose of FDG did not differ significantly for each pattern. The focal and focal on diffuse patterns were seen in 73 patients, and 65 patients had a focal uptake only on the basal wall; ring uptake in 29 patients, over half in 20 and spot uptake in 16 patients. Conclusions: The physiological myocardial uptake showed several patterns. Focal uptake was often seen in patients with cardiac disease, but it did not always indicate an abnormal finding when the accumulation was only on the basal wall.
(Keyword)
F-FDG PET / heart / physiological myocardial uptake / fasting state
Yoshihiro Tanaka, Hitoshi Ikushima, Kazuya Kondo, Koichiro Kenzaki, Yoshimi Bando, Youichi Otomi and Hiroshi Maezawa : The value of diagnostic imaging in neoadjuvant chemoradiation therapy for non-small cell lung cancer, Japanese Journal of Clinical Radiology, Vol.58, No.1, 222-228, 2013.
Hayato Nose, Hideki Otsuka, Youichi Otomi, Kaori Terazawa, Shoichiro Takao, Seiji Iwamoto and Masafumi Harada : Correlations between F-18 FDG PET/CT and pathological findings in soft tissue lesions., The Journal of Medical Investigation : JMI, Vol.60, No.3-4, 184-190, 2013.
(Summary)
Objective: To evaluate the correlations between F-18 FDG uptake imaged with PET/CT and pathological findings in soft tissue lesions. Methods: Fifty-four soft tissue lesions in 47 patients were evaluated. The correlations between the degree of FDG uptake, pathological type and grade, and MRI signal intensity and/or enhancement pattern were evaluated. Tumor FDG uptake was quantified by the maximum standardized uptake value (SUVmax). Results: Thirty-one lesions were malignant and twenty-three lesions were benign. The difference between SUVmax in the malignant and benign groups was statistically significant (p<0.001). Malignant myxoid lesions and well differentiated liposarcoma showed low FDG uptake. Benign neurogenic lesions showed low FDG uptake while malignant neurogenic tumors showed high FDG uptake, and the difference between SUVmax in the benign and malignant lesions was statistically significant (p<0.001). In a neurofibromatosis type-1 patient who had multiple neurogenic tumors, FDG-PET/CT could distinguish malignant peripheral nerve sheath tumors from other benign lesions with similar MRI findings. Conclusions: FDG-PET/CT is useful for differentiating malignant from benign soft tissue lesions, but malignant soft tissue lesions may show various patterns on FDG-PET, and MRI may be helpful for a differential diagnosis. J. Med. Invest. 60: 184-190, August, 2013.
Youichi Otomi, Hideki Otsuka, Naomi Morita, Kaori Terazawa, Kaori Furutani, Masafumi Harada and Hiromu Nishitani : Relationship between FDG uptake and the pathological risk category in gastrointestinal stromal tumors., The Journal of Medical Investigation : JMI, Vol.57, No.3-4, 270-274, 2010.
(Summary)
To evaluate (18)F-fluorodeoxyglucose (FDG) uptake and the pathological risk category of gastrointestinal stromal tumors (GISTs), and to investigate the possibility of determining the pathological risk category by positron emission tomography/computed tomography (PET/CT). Patients and We undertook 29 PET/CT studies in 20 patients with GISTs. Eleven of the 20 patients underwent PET/CT prior to therapy, with three of these also undergoing follow-up PET/CT after operation or imatinib therapy. All eleven lesions imaged before treatment were FDG-positive on PET/CT. Seven of these eleven primary lesions were categorized as high risk and the other four primary lesions were categorized as low or intermediate risk. There was a significant difference between the maximum standardized uptake value (SUVmax) of the primary lesions categorized as high risk (11.8±3.15) and that of the primary lesions categorized as low and intermediate risk (2.88±0.47) (p<0.001). Recurrent tumors were also shown as FDG-positive. Primary GISTs and recurrent tumors can be detected by PET/CT. Our study suggests that the degree of FDG uptake is a useful indicator of risk category. In addition, PET/CT is probably useful for follow-up examinations of GIST after operation or imatinib therapy. J. Med. Invest. 57: 270-274, August, 2010.
Kaori Terazawa, Hideki Otsuka, Youichi Otomi, Naomi Morita, Shoichiro Takao, Seiji Iwamoto, Kyosuke Osaki, Masafumi Harada and Hiromu Nishitani : How to manage RI venography in pre-orthopedic surgery patients, Annals of Nuclear Medicine, Vol.24, No.2, 107-113, 2010.
(Summary)
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.
(Keyword)
Adult / Aged / Aged, 80 and over / Female / Humans / Male / Middle Aged / Organotechnetium Compounds / Orthopedics / Phlebography / Radioisotopes / Serum Albumin / Venous Thromboembolism
Takayoshi Shinya, Matsushita Tomoki, Mitsuhashi Ryota, Saya Matsuzaki, Onishi Hajime, Yuka Hiroshima, Youichi Otomi, Michiko Kubo and Masafumi Harada : Usefulness of F-18 FDG PET/CT imaging in Hepatic Lesions, 13th Congress of the World Federation of Nuclear Medicine and Biology, Sep. 2022.
2.
Youichi Otomi, Hideki Otsuka, Kaori Terazawa and Masafumi Harada : An increased physiological fluorodeoxyglucose uptake in the liver and blood pool among patients with renal failure, ECR 2019, Wien, Feb. 2019.
3.
Moriaki Yamanaka, Youichi Otomi, Kaori Terazawa, Ryota Bando, Hideki Otsuka and Masafumi Harada : To compare diagnostic ability of thallium-201 SPECT for brain tumor between quantitative evaluation, semi- quantitative evaluation and ADC values upon MRI., JNM, Vol.59, No.1, 1434, Philadelphia, Jun. 2018.
4.
Youichi Otomi, Kaori Terazawa, Hideki Otsuka, Moriaki Yamanaka, Michiko Kubo and Masafumi Harada : The relationship between the tumor FDG uptake, metastatic potential, and the FIGO stage in patients with uterine cervical cancer, JNM, Vol.59, No.1, 393, Philadelphia, Jun. 2018.
5.
Youichi Otomi : The physiological accumulation of FDG in the muscles in relation to the side of intravenous administration, 29th Annual Congress of the European Association of Nuclear Medicine, Oct. 2016.
6.
Youichi Otomi : Increased 18F-fluorodeoxyglucose(FDG) accumulation in bilateral adrenal glands found in patients suffering from vasovagal reflex due to blood vessel puncture on administration of FDG., SNMMI annual meeting 2016, Jun. 2016.
7.
Youichi Otomi, 大塚 秀樹, 新家 崇義, 寺澤 かおり, 久保 典子 and 原田 雅史 : FDG PET/CT of bone lesions, Hamburg, Oct. 2015.
8.
Takashi Abe, 苛原 早保, Youichi Otomi, 小濵 祐樹, 山中 森晶 and 岩本 誠司 : Discrepancy Between Arterial Spin Labeling Images and Contrast-Enhanced Images of Brain Tumors, 国際磁気共鳴医学会, Jun. 2015.
9.
Hitoshi Ikushima, Kazuya Kondo and Youichi Otomi : Treatmet effect of eoadjuvat chemoradiatio therapy for osmall cell lug cacer evaluated by multi-modality imaging and histopathological analyses, ASTRO 54, Sep. 2012.
10.
Youichi Otomi, Hideki Otsuka, Hayato Nose, Kaori Terazawa, Hitoshi Ikushima and Masafumi Harada : FDG-PET/CT in esophageal lesions other than squamous cell carcinoma and adenocarcinoma, Miami, Jun. 2012.
11.
Youichi Otomi, Hideki Otsuka, Hayato Nose, Kaori Terazawa, Hitoshi Ikushima and Masafumi Harada : Does the H/M ratio of I-123 MIBG match the cardiac function in Parkinson's disease patients?, Miami, Jun. 2012.
Bollos Leah, Ryosuke Kasai, Youichi Otomi, Shoichiro Takao, Hitoshi Ikushima, Hideki Otsuka and Masafumi Harada : Prediction model of coronary artery calcification risk basis for radiomics features of pericoronary fat in coronary computed tomography, 第59回日本医学放射線学会秋季臨床大会, Sep. 2023.
3.
Yuka Hiroshima, Takayoshi Shinya, Hitoshi Ikushima, Youichi Otomi, Hideki Otsuka, Chisato Tonoiso, Akiko Kubo, Takashi Kawanaka, Yasushi Takagi and Masafumi Harada : Multi-modality Imaging for the Patients with Metastatic Brain Tumors After Stereotactic Irradiation, The 82nd Annual Meeting of the Japan Radiological Society, Apr. 2023.
Youichi Otomi, Takayoshi Shinya, Hideki Otsuka and Masafumi Harada : Frequency of FDG-avid supraclavicular lymph nodes and the number of FDG-avid lymph nodes on PET/CT after vaccination: COVID-19 vs. influenza, 第81回日本医学放射線学会総会, Apr. 2022.
11.
Takayoshi Shinya, Okada Naoko, MATSUSHITA Tomoki, Saya Matsuzaki, Yuki Matsumoto, Youichi Otomi, Michiko Kubo, Hideki Otsuka and Masafumi Harada : Review of Multimodality Imaging in Small Bowel Tumors: a review of old and new techniques, 第81回日本医学放射線学会総会, Apr. 2022.
Hozumi Yoshihara, Midori Yoshida, Hidehiko Hosoki, Youichi Otomi, Masafumi Amano, 湯浅 将生, Kenji Yamada, 川田 直伸, Masafumi Harada and Naoki Maeda : Current status of CT examination in national university hospitals with dental faculty, 日本歯科放射線学会, 48, Oct. 2018.
(Keyword)
dental care / radiation
20.
Hozumi Yoshihara, Hidehiko Hosoki, 久米 芳生, Youichi Otomi, Masafumi Amano, 湯浅 将生, Kenji Yamada, 川田 直伸, Masafumi Harada and Naoki Maeda : Changes in the number of intraoral and panoramic radiography at department of oral radiology, 日本歯科放射線学会, 47, Oct. 2018.
Takashi Abe, 苛原 早保, 小濵 祐樹, 山中 森晶, Youichi Otomi and 岩本 誠司 : Differentiation of recurrence from radiation necrosis after radiation therapy with ASL and DCE permeability MR imaging with histogram analysis, 日本医学放射線学会総会, Apr. 2015.
28.
Takashi Abe, 苛原 早保, 小濵 祐樹, 山中 森晶, Youichi Otomi and 岩本 誠司 : The measurement of 2-hyroxyglutarate by using short TE MRS in CNS neoplasms: preliminary result, 日本医学放射線学会総会, Apr. 2015.
29.
Takashi Abe, 苛原 早保, 小濱 祐樹, 山中 森晶, Youichi Otomi and Seiji Iwamoto : MRS findings of hereditary diffuse leukoencephalopathy with spheroids, Mar. 2015.