F-FDG PET/CT after COVID-19 Vaccination: A Direct Comparison Study with Influenza Vaccination.

F-FDG PET/CT examination is recommended by a longer interval from vaccination than in the influenza vaccine.

Molecular Imaging and Radionuclide Therapy


F-FDG PET/CT in the Evaluation of Adult Alveolar Rhabdomyosarcoma.

C-methionine PET/CT for accurately assessing the extent of alveolar rhabdomyosarcoma, especially in cases with intracranial infiltration or those approximating the brain.


低Na血症を合併した抗LGI1抗体陽性辺縁系脳炎の一例

低Na血症を合併した抗LGI1抗体陽性辺縁系脳炎の一例


Imaging features of a myoepithelial carcinoma of the nasal cavity: A case report and literature review

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.


F-FDG PET/CT Showing Rare Mediastinal Growing Teratoma Syndrome Following Chemotherapy.


Increased 18F-FDG Uptake in the Axillary Lymph Nodes of Vaccinated Side Associated with COVID-19 Vaccination

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.


Multicystic Biliary Hamartoma With Xanthogranulomatous Inflammation on 18F-FDG PET/CT.

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.


Malignant Small Bowel Neoplasms: a review of post-contrast multiphasic multidetector computed tomography

Small bowel neoplasms are rare and account for 3-6% of all gastrointestinal neoplasms. For the diagnosis of small bowel neoplasms, differentiating normal bowel tissue from tumor is critical and depends on imaging modality and scanning techniques. The detection and characterization of small bowel neoplasms have recently improved with the advance of computed tomography (CT) technology. Post-contrast multiphasic CT is an aid to detection and recognition of the vascular nature of small bowel neoplasms. Understanding the typical post-contrast multiphasic CT features of small bowel neoplasms is important because of overlapping features and the necessity of evaluating associated complications and metastases to lymph node and other organs. However, accurate classification of pathologies is still challenging in clinical practice. Texture analysis can quantify complex mathematical patterns within the gray-level distribution of the pixels and voxels of digital images, and texture analysis of the post-contrast multidetector CT data of various tumors has been attracting attention in recent years. The aim of this article is to provide a comprehensive guide to the relevant imaging features for different types of malignant small bowel neoplasms. J. Med. Invest. 69 : 19-24, February, 2022.

The Journal of Medical Investigation : JMI


Increased physiological [18F] FDG uptake in the liver and blood pool among patients with impaired renal function

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.

Nuclear Medicine Review. Central & Eastern Europe


MRI and CT features of a malignant myoepithelioma of the scrotum: A case report and literature review

Malignant myoepithelioma of the scrotum is extremely rare. We report the case of a 51-year-old man with malignant myoepithelioma of the scrotum, wherein computed tomography and magnetic resonance imaging revealed a lobulated soft tissue mass with calcification, cystic component, and solid component with gradual contrast enhancement on dynamic contrast-enhanced scans. The patient presented with scrotal induration, and there was no elevation of tumor markers and no evidence of a metastatic lesion on computed tomography and magnetic resonance imaging. Histopathological examination of the resected scrotal specimen confirmed a well-circumscribed solid tumor with septa, a small area of hemorrhage, and necrosis. The subsequent diagnosis was malignant myoepithelioma of the scrotum. This case shows that scrotal malignant myoepithelioma might appear as a well-defined lobulated mass with cystic regions. We conjecture that the enhancement pattern and apparent diffusion coefficient values can be potential markers for scrotal myoepithelial tumors.


Usefulness of right ventriculography compared with computed tomography for ruling out the possibility of lead perforation before lead extraction


A reduced physiological 18 F-fluorodeoxyglucose uptake in the brain and liver caused by malignant lymphoma being deprived of the tracer

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.


Magnetic resonance imaging findings of a myxoid leiomyosarcoma of the uterus: A case report and literature review


Clinical application of dynamic 18F-fluorodeoxyglucose positron-emission tomography / computed tomography in the differential diagnoses of musculoskeletal lesions

We aimed to assess the differential diagnostic efficacy of dynamic F-18 fluorodeoxyglucose (FDG) positron emission tomography / computed tomography (PET / CT) and to evaluate the appropriate scan timings for diagnosis of musculoskeletal lesions (MSLs). Dynamic scans (5-15 [phase 1], 15-25 [phase 2], and 25-35 [phase 3] min after F-18 FDG injection) and dual-time-point scans (1 and 2 h after injection) were acquired for 23 MSLs [4 benign MSLs (BMSLs). 10 primary malignant musculoskeletal tumors (PMMSTs), and 9 metastatic musculoskeletal tumors (MMSTs)]. We compared the maximum standardized uptake values (SUVmax) and corresponding retention indices for dynamic (RI-SUVdyn) and dual-time-point (RI-SUVdual) scans and evaluated diagnostic efficacy using receiver operating characteristic (ROC) curve analyses. The SUVmax gradually decreased or was almost identical with minimal fluctuation in 3 BMSLs and 1 PMMST. SUVmax increased over time after phase 2 in 18 malignant MSLs (MMSLs). There were significant differences in SUVmax (for all time phases) and RI-SUV dual between BMSLs and MMSLs and between PMMSTs and MMSTs. In the ROC analyses, the areas under the curve for SUV in phases 2 and 3 were highest for differentiating BMSLs from MMSLs and PMMSTs from MMSTs, respectively. Dynamic F-18 FDG PET / CT is valuable for diagnosis of musculoskeletal lesions. J. Med. Invest. 68 : 96-104, February, 2021


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.

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.


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.

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.


Increased (18)F-fluorodeoxyglucose accumulation in bilateral adrenal glands of the patients suffering from vasovagal reaction due to blood vessel puncture.

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.


Predicting pleural invasion using HRCT and 18F-FDG PET/CT in lung adenocarcinoma with pleural contact.

To evaluate the relevance of high-resolution computed tomography (HRCT) findings and fluorine-18-fluorodeoxyglucose ((18)F-FDG) uptake for risk stratification of visceral pleural invasion by lung adenocarcinoma. The HRCT findings and (18)F-FDG uptake for lung adenocarcinomas with pleural contact on CT were retrospectively analyzed in 208 consecutive patients (94 females and 114 males; median age, 69.0 years) between January 2009 and December 2013, with institutional review board approval. The HRCT findings and maximum standardized uptake value (SUV max) were recorded for each patient. Multivariate logistic regression was used for statistical analysis, and subgroup analysis stratified for whole tumor size ≤ 3 cm was also performed. Multivariate analysis showed that SUV max [odds ratio (OR) 1.09, 95 % confidence interval (CI) 1.02-1.16, P = 0.014] and obtuse angle (OR 4.14, 95 % CI 1.97-8.74, P < 0.001) were significant independent predictors for visceral pleural invasion. Receiver operating characteristic (ROC) analysis showed that, compared with the multivariate models [area under the curve (Az) 0.819-0.829], SUV max alone (Az 0.815) was useful in predicting visceral pleural invasion. In the subgroup analysis, multivariate analysis showed that SUV max (OR 1.29, 95 % CI 1.12-1.50, P = 0.001) and contact length with the pleura (OR 1.13, 95 % CI 1.05-1.22, P = 0.001) were significant independent predictors for visceral pleural invasion. ROC analysis showed that SUV max alone (Az 0.844) showed similar diagnostic performance to the multivariate models (Az 0.845-0.857). SUV max alone and multivariate models including SUV max are useful for the prediction of visceral pleural invasion by lung adenocarcinoma.


FDG-PET/CTによる口腔悪性腫瘍頸部リンパ節転移診断の検討

FDG-PET/CTによる口腔悪性腫瘍頸部リンパ節転移診断の検討


Diagnostic value of Thallium-201 scintigraphy in differentiating malignant bone tumors from benign bone lesions.

This retrospective study aims to evaluate the diagnostic capacity of thallium-201 (201Tl) scintigraphy for differentiating malignant bone tumors from benign bone lesions. Between January 2006 and December 2012, 279 patients with bone lesions (51 malignant and 228 benign) underwent 201Tl scintigraphy before treatment. To evaluate 201Tl uptake, we investigated tumor-to-background contrast (TBC) as well as TBC washout rate (WR). The differences of TBC on early and delayed images and WR were estimated by the Mann-Whitney U test. Receiver operating characteristic (ROC) analyses were used to determine the cut-off TBC values for differentiating malignant bone tumors from benign bone lesions. There were statistically significant differences in median TBC between malignant tumors and benign lesions. These differences occurred for early imaging (1.57 vs. 0.09, p < 0.001) as well as for delayed imaging (0.83 vs. 0.07, p < 0.001). However, there was no statistical difference in WR between malignant tumors and benign lesions (44 vs. 43 %, NS). The chosen TBC cut-off value was 0.68 for early imaging and 0.38 for delayed imaging. Using these cut-off values, the prediction of malignancy had a 77 % sensitivity, 74 % specificity, and 75 % accuracy for early imaging and an 80 % sensitivity, 76 % specificity, and 77 % accuracy for delayed imaging. 201Tl scintigraphy may have the ability to distinguish malignant bone tumors from benign bone lesions.


Both a visual and a semiquantitative analysis for differentiating benign from malignant chondrogenic bone tumors using Tc-99m (V) DMSA scintigraphy: a prospective study.

The aims of this prospective study were to assess the relationship between tumor aggressiveness and Tc-99m (V) dimercaptosuccinic acid (DMSA) uptake in chondrogenic bone tumors and the value of Tc-99m (V) DMSA scintigraphy for differentiating benign from malignant tumors. Twenty-four patients with chondrogenic tumors (19 benign and five malignant) underwent Tc-99m DMSA (V) scintigraphy. Radiopharmaceutical uptake was classified using a three-point scale to allow a visual-only analysis, and a tumor-to-background contrast (TBC) was computed using regions of interest to provide a semiquantitative analysis. Spearman's correlation coefficient was used to assess the correlation between tumor aggressiveness and TBC. The difference in TBC between benign and malignant tumors was analyzed with the Mann-Whitney U-test. An appropriate cutoff value of TBC was chosen for the diagnosis of malignancy of a tumor using receiver operating characteristic analysis. Six benign tumors showed negative uptake (uptake score 0), whereas 13 benign tumors showed positive uptake (n=10 uptake score 1; n=3 uptake score 2). All chondrosarcomas showed positive uptake (n=2 uptake score 1; n=3 uptake score 2). A significant correlation was found between tumor aggressiveness and TBC. A significant difference was seen in TBC between benign and malignant tumors. With the chosen cutoff value of TBC equal to 0.611, the sensitivity was 80.0%, specificity was 78.9%, the positive predictive value was 50.0%, and the negative predictive value was 93.8%. Tc-99m (V) DMSA scintigraphy may have the potential to improve diagnostic methods for detecting chondrosarcomas using visual and/or semiquantitative analyses.


Editorial Comment: Newly Developed Cross-Platform Method for Calibration of Iodine Quantification on Dual-Energy CT Across Manufacturers