Search

Abstract: Abdominal-wall metastasis following laparoscopic surgery for colorectal cancer is rare. We describe FDG PET/MRI findings in a case of isolated abdominal incisional site metastasis after laparoscopic surgery for colon cancer. The abdominal-wall metastasis showed slight hyperintensity on T2-weighted fat-suppressed image and intense focal FDG uptake on PET. This case demonstrates the usefulness of FDG PET/MRI in detecting the atypical metastasis from colon cancer., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Reactive astrocytes play an important role in the development of Alzheimer's disease (AD). Here, we aimed to investigate the temporospatial relationships among monoamine oxidase-B, tau and amyloid-β (Aβ), translocator protein, and glucose metabolism by using multitracer imaging in AD transgenic mouse models. Positron emission tomography (PET) imaging with [ 18 F]SMBT-1 (monoamine oxidase-B), [ 18 F]florbetapir (Aβ), [ 18 F]PM-PBB3 (tau), [ 18 F]fluorodeoxyglucose (FDG), and [ 18 F]DPA-714 (translocator protein) was carried out in 5- and 10-month-old APP/PS1, 11-month-old 3×Tg mice, and aged-matched wild-type mice. The brain regional referenced standard uptake value (SUVR) was computed with the cerebellum as the reference region. Immunofluorescence staining was performed on mouse brain tissue slices. [ 18 F]SMBT-1 and [ 18 F]florbetapir SUVRs were greater in the cortex and hippocampus of 10-month-old APP/PS1 mice than in those of 5-month-old APP/PS1 mice and wild-type mice. No significant difference in the regional [ 18 F]FDG or [ 18 F]DPA-714 SUVRs was observed in the brains of 5- or 10-month-old APP/PS1 mice or wild-type mice. No significant difference in the SUVRs of any tracer was observed between 11-month-old 3×Tg mice and age-matched wild-type mice. A positive correlation between the SUVRs of [ 18 F]florbetapir and [ 18 F]DPA-714 in the cortex and hippocampus was observed among the transgenic mice. Immunostaining validated the distribution of MAO-B and limited Aβ and tau pathology in 11-month-old 3×Tg mice; and Aβ deposits in brain tissue from 10-month-old APP/PS1 mice. In summary, these findings provide in vivo evidence that an increase in astrocyte [ 18 F]SMBT-1 accompanies Aβ accumulation in APP/PS1 models of AD amyloidosis., (© 2024. The Author(s).)

Purpose: This study aimed to investigate the value of 68 Ga-fibroblast activation protein inhibitor (FAPI) PET/MR semiquantitative parameters in the prediction of tumor response and resectability after neoadjuvant therapy in patients with pancreatic cancer., Patients and Methods: This study was performed retrospectively in patients with borderline resectable or locally advanced pancreatic cancer who underwent 68 Ga-FAPI PET/MRI from June 2020 to June 2022. The SUV max , SUV mean , SUV peak , uptake tumor volume (UTV), and total lesion FAP expression (TLF) of the primary tumor were recorded. The target-to-background ratios (TBRs) of the primary tumor to normal tissue muscle (TBR muscle ) and blood (TBR blood ) were also calculated. In addition, the minimum apparent diffusion coefficient value of the tumor was measured. After 3-4 cycles of gemcitabine + nab-paclitaxel chemotherapy, patients were divided into responders and nonresponders groups according to RECIST criteria (v.1.1). They were also divided into resectable and unresectable groups according to the surgical outcome. The variables were compared separately between groups., Results: A total of 18 patients who met the criteria were included in this study. The UTV and TLF were significantly higher in nonresponders than in responders ( P < 0.05). The SUV max , SUV mean , and TBR muscle were significantly higher in unresectable patients than in resectable ones ( P < 0.05). Receiver operating characteristic curve analysis identified UTV (area under the curve [AUC] = 0.840, P = 0.015) and TLF (AUC = 0.877, P = 0.007) as significant predictors for the response to gemcitabine + nab-paclitaxel chemotherapy, with cutoff values of 25.05 and 167.38, respectively. In addition, SUV max (AUC = 0.838, P = 0.016), SUV mean (AUC = 0.812, P = 0.026), and TBR muscle (AUC = 0.787, P = 0.041) were significant predictors of the resectability post-NCT, with cutoff values of 14.0, 6.0, and 13.9, respectively. According to logistic regression analysis, TLF was found to be significantly associated with tumor response ( P = 0.032) and was an independent predictor of tumor response ( P = 0.032). In addition, apparent diffusion coefficient value was an independent predictor of tumor resectability ( P = 0.043)., Conclusions: This pilot study demonstrates the value of 68 Ga-FAPI PET/MR for the prediction of tumor response and resectability after neoadjuvant therapy. It may aid in individualized patient management by guiding the treatment regimens., Competing Interests: Conflicts of interest and sources of funding: The authors declare that they have no conflict of interest. We gratefully acknowledge the financial supports by the National Natural Science Foundation of China (grant no. 82172712), the “234 Discipline Climbing Plan” of the First Affiliated Hospital of Naval Medical University (grant no. 2019YXK033, 2019YPT002, and 2020YPT002), and Guhai Plan in the 14th Five-Year Plan Period of Changhai Hospital (grant no. GH145-22)., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Reactive astrocytes play an important role in the development of Alzheimer's disease and primary tauopathies. Here, we aimed to investigate the relationships between reactive astrocytes. Microgliosis and glucose metabolism with Tau and amyloid beta pathology by using multi-tracer imaging in widely used tauopathy and familial Alzheimer's disease mouse models., Results: Positron emission tomography imaging using [ 18 F]PM-PBB3 (tau), [ 18 F]florbetapir (amyloid-beta), [ 18 F]SMBT-1 (monoamine oxidase-B), [ 18 F]DPA-714 (translocator protein) and [ 18 F]fluorodeoxyglucose was carried out in 3- and 7-month-old rTg4510 tau mice, 5 × FAD familial Alzheimer's disease mice and wild-type mice. Immunofluorescence staining was performed to validate the pathological distribution in the mouse brain after in vivo imaging. We found increased regional levels of [ 18 F]PM-PBB3, [ 18 F]SMBT-1, and [ 18 F]DPA-714 and hypoglucose metabolism in the brains of 7-month-old rTg4510 mice compared to age-matched wild-type mice. Increased [ 18 F]SMBT-1 uptake was observed in the brains of 3, 7-month-old 5 × FAD mice, with elevated regional [ 18 F]florbetapir and [ 18 F]DPA-714 uptakes in the brains of 7-month-old 5 × FAD mice, compared to age-matched wild-type mice. Positive correlations were shown between [ 18 F]SMBT-1 and [ 18 F]PM-PBB3, [ 18 F]DPA-714 and [ 18 F]PM-PBB3 in rTg4510 mice, and between [ 18 F]florbetapir and [ 18 F]DPA-714 SUVRs in 5 × FAD mice., Conclusion: In summary, these findings provide in vivo evidence that reactive astrocytes, microglial activation, and cerebral hypoglucose metabolism are associated with tau and amyloid pathology development in animal models of tauopathy and familial Alzheimer's disease., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2024. Published by Elsevier B.V.)

Objectives: To compare prostate-specific membrane antigen (PSMA) PET with multiparametric MRI (mpMRI) in the diagnosis of pretreatment prostate cancer (PCa)., Methods: Pubmed, Embase, Medline, Web of Science, and Cochrane Library were searched for eligible studies published before June 22, 2022. We assessed risk of bias and applicability by using QUADAS-2 tool. Data synthesis was performed with Stata 17.0 software, using the "midas" and "meqrlogit" packages., Results: We included 29 articles focusing on primary cancer detection, 18 articles about primary staging, and two articles containing them both. For PSMA PET versus mpMRI in primary PCa detection, sensitivities and specificities in the per-patient analysis were 0.90 and 0.84 (p<0.0001), and 0.66 and 0.60 (p <0.0001), and in the per-lesion analysis they were 0.79 and 0.78 (p <0.0001), and 0.84 and 0.82 (p <0.0001). For the per-patient analysis of PSMA PET versus mpMRI in primary staging, sensitivities and specificities in extracapsular extension detection were 0.59 and 0.66 (p =0.005), and 0.79 and 0.76 (p =0.0074), and in seminal vesicle infiltration (SVI) detection they were 0.51 and 0.60 (p =0.0008), and 0.93 and 0.96 (p =0.0092). For PSMA PET versus mpMRI in lymph node metastasis (LNM) detection, sensitivities and specificities in the per-patient analysis were 0.68 and 0.46 (p <0.0001), and 0.91 and 0.90 (p =0.81), and in the per-lesion analysis they were 0.67 and 0.36 (p <0.0001), and 0.99 and 0.99 (p =0.18)., Conclusion: PSMA PET has higher diagnostic value than mpMRI in the detection of primary PCa. Regarding the primary staging, mpMRI has potential advantages in SVI detection, while PSMA PET has relative advantages in LNM detection., Clinical Relevance Statement: The integration of prostate-specific membrane antigen (PSMA) PET into the diagnostic pathway may be helpful for improving the accuracy of prostate cancer detection. However, further studies are needed to address the cost implications and evaluate its utility in specific patient populations or clinical scenarios. Moreover, we recommend the combination of PSMA PET and mpMRI for cancer staging., Key Points: • Prostate-specific membrane antigen PET has higher sensitivity and specificity for primary tumor detection in prostate cancer compared to multiparametric MRI. • Prostate-specific membrane antigen PET also has significantly better sensitivity and specificity for lymph node metastases of prostate cancer compared to multiparametric MRI. • Multiparametric MRI has better accuracy for extracapsular extension and seminal vesicle infiltration compared to ate-specific membrane antigen PET., (© 2023. The Author(s), under exclusive licence to European Society of Radiology.)

Tau pathology and its spatial propagation in Alzheimer's disease (AD) play crucial roles in the neurodegenerative cascade leading to dementia. However, the underlying mechanisms linking tau spreading to glucose metabolism remain elusive. To address this, we aimed to examine the association between pathologic tau aggregation, functional connectivity, and cascading glucose metabolism and further explore the underlying interplay mechanisms. In this prospective cohort study, we enrolled 79 participants with 18 F-Florzolotau positron emission tomography (PET), 18 F-fluorodeoxyglucose PET, resting-state functional, and anatomical magnetic resonance imaging (MRI) images in the hospital-based Shanghai Memory Study. We employed generalized linear regression and correlation analyses to assess the associations between Florzolotau accumulation, functional connectivity, and glucose metabolism in whole-brain and network-specific manners. Causal mediation analysis was used to evaluate whether functional connectivity mediates the association between pathologic tau and cascading glucose metabolism. We examined 22 normal controls and 57 patients with AD. In the AD group, functional connectivity was associated with Florzolotau covariance (β = .837, r = 0.472, p < .001) and glucose covariance (β = 1.01, r = 0.499, p < .001). Brain regions with higher tau accumulation tend to be connected to other regions with high tau accumulation through functional connectivity or metabolic connectivity. Mediation analyses further suggest that functional connectivity partially modulates the influence of tau accumulation on downstream glucose metabolism (mediation proportion: 49.9%). Pathologic tau may affect functionally connected neurons directly, triggering downstream glucose metabolism changes. This study sheds light on the intricate relationship between tau pathology, functional connectivity, and downstream glucose metabolism, providing critical insights into AD pathophysiology and potential therapeutic targets., (© 2024 The Authors. Human Brain Mapping published by Wiley Periodicals LLC.)

Background: Recent development in tau-sensitive tracers has sparkled significant interest in tracking tauopathies using positron emission tomography (PET) biomarkers. However, the ability of 18 F-florzolotau PET imaging to topographically characterize tau pathology in corticobasal syndrome (CBS) remains unclear. Further, the question as to whether disease-level differences exist with other neurodegenerative tauopathies is still unanswered., Objective: To analyze the topographical patterns of tau pathology in the living brains of patients with CBS using 18 F-florzolotau PET imaging and to examine whether differences with other tauopathies exist., Methods: 18 F-florzolotau PET imaging was performed in 20 consecutive patients with CBS, 20 cognitively healthy controls (HCs), 20 patients with Alzheimer's disease (AD), and 16 patients with progressive supranuclear palsy-Richardson's syndrome (PSP-RS). Cerebrospinal fluid (CSF) levels of β-amyloid biomarkers were quantified in all patients with CBS. 18 F-florzolotau uptake was quantitatively assessed using standardized uptake value ratios., Results: Of the 20 patients with CBS, 19 (95%) were negative for CSF biomarkers of amyloid pathology; of them, three had negative 18 F-florzolotau PET findings. Compared with HCs, patients with CBS showed increased 18 F-florzolotau signals in both cortical and subcortical regions. In addition, patients with CBS were characterized by higher tracer retentions in subcortical regions compared with those with AD and showed a trend toward higher signals in cortical areas compared with PSP-RS. An asymmetric pattern of 18 F-florzolotau uptake was associated with an asymmetry of motor severity in patients with CBS., Conclusions: In vivo 18 F-florzolotau PET imaging holds promise for distinguishing CBS in the spectrum of neurodegenerative tauopathies. © 2023 International Parkinson and Movement Disorder Society., (© 2023 International Parkinson and Movement Disorder Society.)

Background: Non-invasive diagnosis of IDH1 mutation for gliomas has great clinical significance, and PET has natural advantage to detect metabolism, as IDH mutated gliomas share lower glucose consumption., Methods: Clinical data of patients with gliomas and 18 F-FDG PET were retrospectively reviewed. Receiver operating characteristic curve (ROC) analysis was conducted, and standard uptake value (SUV) was estimated in combination with grades or IDH1 mutation. The glucose consumption was investigated with U251 cells expressing wild-type or mutated IDH1 by glucose assay. Quantification of glucose was determined by HPLC in clinical tissues. Meanwhile, bioinformatics and western blot were applied to analyze the expression level of metabolic enzymes (e.g. HK1, PKM2, PC) in gliomas., Results: Seventy-one glioma cases were enrolled, including 30 carrying IDH1 mutation. The sensitivity and specificity dependent on SUV max (3.85) predicting IDH1 mutation reached 73.2 and 86.7%, respectively. The sensitivity and specificity of differentiating grades by SUVmax (3.1) were 92.3 and 64.4%, respectively. Glucose consumption of U251 IDH1 mutant cells (0.209 ± 0.0472 mg/ml) was obviously lower than IDH1wild-type cells (0.978 ± 0.0773 mg/ml, P = 0.0001) and astrocyte controls (0.335 ± 0.0592 mg/ml, P = 0.0451). Meanwhile, the glucose quantity in IDH1mutant glioma samples were significantly lower than those in IDH1 wild-type tissues (1.033 ± 1.19608 vs 6.361 ± 4.3909 mg/g, P = 0.0051). Silico analysis and western blot confirmed that HK1 and PKM2 in IDH1 wild-type gliomas were significantly higher than in IDH1 mutant group, while PC was significantly higher in IDH1 mutant gliomas., Conclusion: SUV max on PET can predict IDH1 mutation with adequate sensitivity and specificity, as is supported by reduced glucose consumption in IDH1 mutant gliomas.

Cerebral β-amyloid deposits and regional glucose metabolism assessed by PET are used to distinguish between Alzheimer disease (AD) and other dementia syndromes. In the present multicenter study, we estimated the prevalence of β-amyloid deposits on PET imaging in a wide variety of dementia syndromes and mild cognitive impairment (MCI) within a memory clinic population. Methods: Of the 1,193 consecutive patients with cognitive impairment (CI) who received 1 11 C-PIB PET or 18 F-AV45 PET or both 11 C-PIB PET and 18 F-AV45 PET, 960 were diagnosed with AD, 36 with frontotemporal dementia (FTD), 5 with dementia with Lewy bodies, 144 with MCI, 29 with vascular dementia, 4 with corticobasal syndrome, and 15 with unclassifiable dementia. Baseline clinical diagnoses were independently established without access to PET imaging results. Apolipoprotein E (ApoE) genotype analysis was performed on CI patients and 231 sex- and age-matched controls. Results: Of the 1,193 CI patients, 860 (72.1%) were amyloid-positive. The prevalence of amyloid positivity in AD and MCI patients was 86.8% (833/960) and 9.7% (14/144), respectively. In FTD patients, the prevalence of β-amyloid deposits was 5.6% (2/36). In the 4 corticobasal syndrome patients, 2 were amyloid-positive. Three of the 5 patients with dementia with Lewy bodies showed amyloid positivity, as did 6 of the 29 vascular dementia (20.7%) patients. The ApoEε4 allele frequency was significantly increased in amyloid-positive CI patients (30.5%) as compared with other amyloid-negative CI patients (14%) or controls (7.3%). Conclusion: Amyloid imaging may potentially be the most helpful parameter for differential diagnosis in dementia, particularly to distinguish between AD and FTD. Amyloid PET can be used in conjunction with the ApoEε4 allele genetic risk test for amyloid deposits., (© 2020 by the Society of Nuclear Medicine and Molecular Imaging.)

Striatal dopamine transporter (DAT) deficiency and abnormal expression of Parkinson's disease (PD)-related pattern (PDRP) have been observed in patients with idiopathic REM sleep behavior disorder (IRBD). This study aimed to investigate the correlations between these two measures with comparison to PD using a dual tracer imaging design. Age-matched 37 IRBD patients, 86 PD patients, and 15 control subjects underwent concurrent PET scans with 11 C-CFT to quantify dopaminergic dysfunction and 18 F-FDG to quantify PDRP expression. IRBD patients were divided into two subgroups: those with relatively normal (IRBD-RN) or abnormal (IRBD-AB) striatal DAT binding. Significantly decreased DAT binding and increased PDRP scores were present in all patient groups, except for IRBD-RN, relative to the controls. There was a significant effect of hemisphere and hemisphere × group interaction for DAT binding but not for PDRP expression. Significant correlations were observed between DAT binding and PDRP expression in the IRBD-AB and PD groups but not in the IRBD-RN group. IRBD patients present with an intermediate state in striatal DAT distribution and PDRP activity between PD and normal controls. The modest correlations between the two measures in both IRBD and PD suggest that differences in network activity cannot be fully explained by nigrostriatal dopaminergic denervation.

Background: Flortaucipir (AV-1451) and pyridinyl-butadienyl-benzothiazole 3 (PBB3) are newly developed and commonly used positron emission tomography (PET) tracers to detect tau deposition in tauopathies, including frontotemporal dementia (FTD). [18F]PM-PBB3, as a second-generation compound, has not been described in FTD so far., Objective: We aim to explore the in vivo performance of [18F]PM-PBB3 tau PET in an FTD case caused by microtubule-associated protein tau (MAPT) mutation and compare the binding to different tau strains between AV-1451 and PBB3., Methods: We reported the clinical and FDG, [18F]AV45 amyloid and [18F]PM-PBB3 tau PET findings in a patient with FTD of P301L MAPT mutation. Based on our results and published data, we summarized and compared the different utilities of tau PET tracers of AV-1451 and PBB3 in FTD with MAPT mutation., Results: The patient demonstrated slightly diffuse [18F]PM-PBB3 tau deposition in cerebral lobes especially in the left frontal lobe overlapping with the hypometabolic region detected by FDG PET. From our analysis of 35 FTD patients with MAPT mutation who underwent tau PET, AV-1451 was positive in all (n = 11) patients with mutations known to cause three and four repeat (3R/4R) tau deposition and in 14.3% (n = 2/14) of 4R tauopathies, while positive PBB3 retention was found in all patients with both 3R/4R (n = 2) and 4R (n = 8) tau., Conclusions: [18F]PM-PBB3 tau PET assisted the diagnosis of FTD with P301L MAPT mutation, and might be useful in the in vivo detection of both 3R/4R and 4R tau domains in the brain of FTD with MAPT mutation.

Objective: Accurate diagnosis of early Alzheimer disease (AD) plays a critical role in preventing the progression of memory impairment. We aimed to develop a new deep belief network (DBN) framework using 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) metabolic imaging to identify patients at the mild cognitive impairment (MCI) stage with presymptomatic AD and to discriminate them from other patients with MCI., Methods: 18F-fluorodeoxyglucose-PET images of 109 patients recruited in the ongoing longitudinal Alzheimer's Disease Neuroimaging Initiative study were included in this analysis. Patients were grouped into 2 classes: (1) stable mild cognitive impairment (n = 62) or (2) progressive mild cognitive impairment (n = 47). Our framework is composed of 4 steps: (1) image preprocessing: normalization and smoothing; (2) identification of regions of interest (ROIs); (3) feature learning using deep neural networks; and (4) classification by support vector machine with 3 kernels. All classification experiments were performed with a 5-fold cross-validation. Accuracy, sensitivity, and specificity were used to validate the results., Result: A total of 1103 ROIs were obtained. One hundred features were learned from ROIs using the DBN. The classification accuracy using linear, polynomial, and RBF kernels was 83.9%, 79.2%, and 86.6%, respectively. This method may be a powerful tool for personalized precision medicine in the population with prediction of early AD progression.

Objectives: To investigate the differences in the pattern of striatal (caudate and putamen) dopamine transporter (DAT) loss in a multiple system atrophy (MSA) cohort, based on the clinical variants parkinsonian subtype (MSA-P) and cerebellar subtype (MSA-C) via (11)C-N-2-carbomethoxy-3-(4-fluorophenyl)-tropane ( 11 C-CFT) positron emission tomography (PET) imaging., Materials and Methods: One hundred and six subjects (forty-one patients with probable MSA-P; forty patients with probable MSA-C; twenty-five healthy controls) underwent 11 C-CFT PET. Subregional 11 C-CFT uptake of bilateral caudate, anterior putamen, and posterior putamen was calculated respectively to measure the striatal dopaminergic function., Results: Significant decrease in DAT binding in striatum was revealed in patients with MSA-C and MSA-P compared to normal controls (all regions, MSA-C vs controls, P < .0001; MSA-P vs controls, P < .0001). DAT reduction was more pronounced in MSA-P patients than that in MSA-C patients (all regions, P < .0001). Eleven of forty MSA-C patients displayed no DAT loss, whereas striatal DAT loss was evident in all MSA-P patients. MSA-P subtype showed a more obvious anteroposterior gradient of DAT loss and more asymmetric dopaminergic dysfunction compared to MSA-C patients., Conclusion: The subtypes of MSA studied here show significantly different spatial/anatomic patterns of striatonigral degeneration which may provide insights into their disease pathophysiology. Specifically, MSA-P patients exhibit an uneven and much greater pronounced loss of dopamine innervation, while a relatively uniform pattern is revealed in patients with the MSA-C. Furthermore, the typical reduction in DAT 11 C-CFT binding in striatum is not present in all MSA-C patients, with a minority of cases showing normal DAT binding., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Progressive supranuclear palsy (PSP) is a rare movement disorder and often difficult to distinguish clinically from Parkinson's disease (PD) and multiple system atrophy (MSA) in early phases. In this study, we report reproducible disease-related topographies of brain network and regional glucose metabolism associated with PSP in clinically-confirmed independent cohorts of PSP, MSA, and PD patients and healthy controls in the USA and China. Using 18 F-FDG PET images from PSP and healthy subjects, we applied spatial covariance analysis with bootstrapping to identify a PSP-related pattern (PSPRP) and estimate its reliability, and evaluated the ability of network scores for differential diagnosis. We also detected regional metabolic differences using statistical parametric mapping analysis. We produced a highly reliable PSPRP characterized by relative metabolic decreases in the middle prefrontal cortex/cingulate, ventrolateral prefrontal cortex, striatum, thalamus and midbrain, covarying with relative metabolic increases in the hippocampus, insula and parieto-temporal regions. PSPRP network scores correlated positively with PSP duration and accurately discriminated between healthy, PSP, MSA and PD groups in two separate cohorts of parkinsonian patients at both early and advanced stages. Moreover, PSP patients shared many overlapping areas with abnormal metabolism in the same cortical and subcortical regions as in the PSPRP. With rigorous cross-validation, this study demonstrated highly comparable and reproducible PSP-related metabolic topographies at network and regional levels across different patient populations and PET scanners. Metabolic brain network activity may serve as a reliable and objective marker of PSP, although cross-validation applying recent diagnostic criteria and classification is warranted., (© 2018 Wiley Periodicals, Inc.)

Dementia with Lewy bodies (DLB) is the second most common degenerative dementia of the central nervous system. The technique 18 F-fluorodeoxyglucose positron emission tomography ( 18 F FDG PET) was used to investigate brain metabolism patterns in DLB patients. Conventional statistical methods did not consider intern metabolism transforming connections between various brain regions; therefore, most physicians do not understand the underlying neuropathology of DLB patients. In this study, 18 F FDG-PET images and graph-theoretical methods were used to investigate alterations in whole-brain intrinsic functional connectivity in a Chinese DLB group and healthy control (HC) group. This experimental study was performed on 22 DLB patients and 22 HC subjects in Huashan Hospital, Shanghai, China. Experimental results indicate that compared with the HC group, the DLB group has severely impaired small-world network. Compared to those of the HC group, the clustering coefficients of the DLB group were higher and characteristic path lengths were longer, and in terms of global efficiencies, those of the DLB group was also lower. Moreover, four significantly altered regions were observed in the DLB group: Inferior frontal gyrus, opercular part (IFG.R), olfactory cortex (OLF.R), hippocampus (HIP.R), and fusiform gyrus (FFG.L). Amongst them, in the DLB group, betweenness centrality became strong in OLF.R, HIP.R, and FFG.L, whereas betweenness centrality became weaker in IFG.R. Finally, IFGoperc.R was selected as a seed and a voxel-wise correlation analysis was performed. Compared to the HC group, the DLB group showed several regions of strengthened connection with IFGoperc.R; these regions were located in the prefrontal cortex and regions of weakened connection were located in the occipital cortex. The results of this paper may help physicians to better understand and characterize DLB patients.

Objectives: 18 F-FDG PET scan is one of the most frequently used neural imaging scans. However, the influence of age has proven to be the greatest interfering factor for many clinical dementia diagnoses when analyzing 18 F-FDG PET images, since radiologists encounter difficulties when deciding whether the abnormalities in specific regions correlate with normal aging, disease, or both. In the present paper, the authors aimed to define specific brain regions and determine an age-correction mathematical model., Methods: A data-driven approach was used based on 255 healthy subjects., Results: The inferior frontal gyrus, the left medial part and the left medial orbital part of superior frontal gyrus, the right insula, the left anterior cingulate, the left median cingulate, and paracingulate gyri, and bilateral superior temporal gyri were found to have a strong negative correlation with age. For evaluation, an age-correction model was applied to 262 healthy subjects and 50 AD subjects selected from the ADNI database, and partial correlations between SUVR mean and three clinical results were carried out before and after age correction., Conclusion: All correlation coefficients were significantly improved after the age correction. The proposed model was effective in the age correction of both healthy and AD subjects.

Objectives: In brain 18 F-FDG PET data intensity normalization is usually applied to control for unwanted factors confounding brain metabolism. However, it can be difficult to determine a proper intensity normalization region as a reference for the identification of abnormal metabolism in diseased brains. In neurodegenerative disorders, differentiating disease-related changes in brain metabolism from age-associated natural changes remains challenging. This study proposes a new data-driven method to identify proper intensity normalization regions in order to improve separation of age-associated natural changes from disease related changes in brain metabolism., Methods: 127 female and 128 male healthy subjects (age: 20 to 79) with brain 18 F-FDG PET/CT in the course of a whole body cancer screening were included. Brain PET images were processed using SPM8 and were parcellated into 116 anatomical regions according to the AAL template. It is assumed that normal brain 18 F-FDG metabolism has longitudinal coherency and this coherency leads to better model fitting. The coefficient of determination R 2 was proposed as the coherence coefficient, and the total coherence coefficient (overall fitting quality) was employed as an index to assess proper intensity normalization strategies on single subjects and age-cohort averaged data. Age-associated longitudinal changes of normal subjects were derived using the identified intensity normalization method correspondingly. In addition, 15 subjects with clinically diagnosed Parkinson's disease were assessed to evaluate the clinical potential of the proposed new method., Results: Intensity normalizations by paracentral lobule and cerebellar tonsil, both regions derived from the new data-driven coherency method, showed significantly better coherence coefficients than other intensity normalization regions, and especially better than the most widely used global mean normalization. Intensity normalization by paracentral lobule was the most consistent method within both analysis strategies (subject-based and age-cohort averaging). In addition, the proposed new intensity normalization method using the paracentral lobule generates significantly higher differentiation from the age-associated changes than other intensity normalization methods., Conclusion: Proper intensity normalization can enhance the longitudinal coherency of normal brain glucose metabolism. The paracentral lobule followed by the cerebellar tonsil are shown to be the two most stable intensity normalization regions concerning age-dependent brain metabolism. This may provide the potential to better differentiate disease-related changes from age-related changes in brain metabolism, which is of relevance in the diagnosis of neurodegenerative disorders., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Histiocytic sarcoma is an extremely rare and aggressive malignant neoplasm of presumed hematopoietic origin. Lymph nodes are the most common sites of involvement. A variety of extranodal sites can be involved, particularly the gastrointestinal tract, soft tissue, skin, and spleen. Radiologic findings of histiocytic sarcoma have been rarely reported. We present a case with histiocytic sarcoma in pericardium, which is an unusual site. Enhanced chest CT showed remarkable enhancement of the tumor. On FDG PET/CT, the tumor showed intense FDG uptake.

Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome is a rare disease, which may be underdiagnosed or misdiagnosed because of nonspecific clinical and imaging findings. We present 2 cases of SAPHO syndrome with MRI, bone scintigraphy, and FDG PET/CT findings. In case 1 with early-stage disease, the active osteitis showed osteolytic bone destruction with increased FDG uptake. In case 2 with late-stage disease, the inactive bone lesions presented as osteosclerosis with normal FDG uptake. Familiarity with the FDG PET/CT findings of SAPHO syndrome in different stages may be helpful for correct diagnosis.

Imaging findings of hepatic lymphoma of mucosa-associated lymphoid tissue (MALT) have been rarely reported before. We present the computed tomography (CT), magnetic resonance imaging (MRI), and fluorine-18-fluorodeoxyglucose (F-FDG) positron emission tomography (PET)/CT findings in a patient with untreated pulmonary and hepatic MALT lymphoma over a 5-year period.On the 1st abdominal MRI scan, the hepatic MALT lymphoma showed multiple hepatic subcapsular masses. On FDG PET/CT, these hepatic tumors showed hypodenisty with FDG uptake similar to the liver on early PET images, and higher than liver on delayed PET images. The patient declined to undergo treatment. Fiver year later, the follow-up MRI and FDG PET/CT showed enlargement and confluence of the hepatic tumors with higher FDG uptake than before. The enlarged hepatic tumors had minimal mass effect. In the hepatic lesions, the blood vessels and bile ducts had no distortion or displacement.The hepatic MALT lymphoma should be taken into consideration when the hepatic tumors have minimal mass effect with the intrahepatic blood vessels and bile ducts normally passing through the tumors. Delayed-time-point FDG PET/CT imaging may be helpful for improving detectability of the hepatic MALT lymphoma., Competing Interests: The authors have no funding and conflicts of interest to disclose.

A 66-year-old man complained of foreign body sensation of the throat and progressive dysphagia without any trigger. Videolaryngoscopy showed a whitish lesion in the epiglottic vallecula. Neck enhanced MRI showed a lesion in epiglottic vallecula with remarkable enhancement. FDG PET/CT showed intense FDG uptake of the lesion with SUVmax of 28. Malignant tumor was suspected. The patient underwent microlaryngoscopic surgery. Histopathologic findings of the specimen were consistent with foreign body granuloma.

Kaposiform hemangioendothelioma (KH) is a rare vascular tumor of intermediate malignancy that occurs mainly in the childhood. Adult patients with KH are rare. Imaging findings of KH have rarely been reported before. We present magnetic resonance imaging (MRI), computed tomography (CT), and fluorine-18-fluorodeoxyglucose (F-FDG) positron emission tomography (PET)/CT findings in an adult patient with KH associated with lymphangiomatosis involving mesentery and ileum.A 22-year-old female complained of a 9-month history of intermittent melena, weakness, and palpitation. Laboratory tests revealed anemia and hypoproteinemia. Fecal occult blood test was positive. Abdominal enhanced MRI and CT showed a large abdominal mass involving mesentery and ileum. On enhanced MRI, there were many hypervascular nodules in the mass. On FDG PET/CT, the mass and the nodules showed slight FDG uptake. Small bowel capsule endoscopy showed numerous grape-shaped red nodules in the luminal wall of the involved ileum. The patient underwent resection of the abdominal mass and a segment of the ileum invaded by the abdominal mass. KH arising within lymphangiomatosis involving mesentery and ileum was confirmed by pathology. After surgery, the patient's symptoms improved.This is the first case of KH associated with lymphangiomatosis involving mesentery and ileum. In this case, the lymphangiomatosis overshadowed the small tumor nodules resulting in unusual imaging findings. Familiarity with these imaging findings is helpful for diagnosis and differential diagnosis of KH.

Purpose: This study aimed to evaluate the fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) findings and pattern of FDG uptake in pancreatic metastases., Materials and Methods: A total of 19 consecutive patients (26 lesions) with histologically or clinically confirmed pancreatic metastases who had undergone (18)F-FDG-PET/CT were enrolled in this retrospective study. Among the 19 patients, 14 patients underwent abdominal contrast-enhanced CT (ceCT). The location, size and FDG uptake patterns of the pancreatic lesions were recorded. Metabolic activity by means of maximum standardised uptake value (SUVmax) was measured by drawing regions of interest at the site of pancreatic lesions. Twenty pancreatic cancer patients were included in this study as comparative data analysis. The difference of SUVmax between pancreatic metastases and primary pancreatic cancer were compared using the Mann-Whitney U test. P < 0.05 was considered significant., Results: Three different patterns of FDG uptake could be distinguished in the pancreatic metastatic lesions, including focal nodule or mass, multiple foci and segmental lesion with high FDG uptake. The average SUVmax in pancreatic metastases was 7.8 ± 6.9 versus 7.4 ± 3.9 in primary pancreatic cancer (P = 0.987 > 0.05). Four intrapancreatic isodense nodules in three patients were undetected on ceCT., Conclusion: The described patterns of FDG uptake findings may be helpful for a better characterisation of pancreatic metastases although semiquantitative analysis using SUVmax could not be used as a criterion for differentiating pancreatic metastases from primary pancreatic cancer. FDG-PET/CT has also an advantage in detecting unsuspected pancreatic metastases which cannot be detected by ceCT imaging. Thus, it is a useful adjunct to the described features on CT.

A 22-year-old man underwent an FDG PET/CT scan to evaluate possible malignancy due to melena and fever for 1 month. The images demonstrated intense FDG activity with an SUVmax of 24.6 in a large mass in the fundus of the stomach. Gastric malignant fibrous histiocytoma was histopathologically confirmed. Malignant fibrous histiocytoma is a high-grade and aggressive sarcoma, which usually occurs in the limbs or retroperitoneum. Malignant fibrous histiocytoma in the stomach is rare.

Primary pulmonary lymphoepithelioma-like carcinomas are extremely rare tumors with better prognosis than other types of non-small cell lung cancer. An 83-year-old man presented with cough and hemoptysis for 2 weeks. Chest CT images showed a cylinder-shaped lesion in the right upper lung. F-FDG PET/CT showed strong FDG uptake (SUVmax, 34.5) of the tumor with ipsilateral hilar lymph node metastases. Video-assisted thoracoscopic lobectomy was performed. Histopathologically, the tumor was composed of epithelial tumor cells with high proliferation index (80%) and abundant lymphoplasmacytic cells, consistent with lymphoepithelioma-like carcinoma.

Primary retroperitoneal mucinous cystadenocarcinoma (PRMC) is an extremely rare neoplasm. We present a case of PRMC with MRI, enhanced CT, and FDG PET/CT findings. Abdominal MRI showed a cystic lesion in the retroperitoneum with a mural nodule. The mural nodule showed progressive enhancement on enhanced CT and intense FDG uptake on early PET/CT with increased SUVmax on delayed PET/CT. Laparoscopy was performed. Retroperitoneal mucinous cystadenocarcinoma was confirmed histopathologically. Metastasis from gastrointestinal tract or ovary was excluded. This case indicates, although rare, PRMC should be considered when a hypermetabolic retroperitoneal cystic lesion with bilateral normal ovaries is found on FDG PET/CT.

Purpose: The aim of this study was to evaluate F-FDG PET/CT findings of malignant nonepithelial prostate tumors and their correlation with MRI and CT images., Patients and Methods: FDG PET/CT findings were reviewed in 12 patients with malignant nonepithelial prostate tumor confirmed by pathology. The location, size, SUVmax, pathologic findings, and available MRI and CT images of the tumors were reviewed., Results: Of the 12 patients (mean age, 41 years; age range, 19-66 years), 9 had normal prostate-specific antigen levels. The mean size of the tumors was 7.1 cm in diameter ranging from 4.6 to 10.5 cm. All the tumors showed increased metabolic activity with mean SUVmax of 17.5 ranging from 3.6 to 46.8. The high-grade malignant tumors tended to show higher FDG uptake, whereas the intermediate-grade and low-grade malignant ones tended to show lower FDG uptake. Seven tumors had local invasion or distant metastases. Lung was the most common metastatic site. On MRI, the tumors showed well-circumscribed or ill-circumscribed margins with inhomogeneous enhancement. On CT, the tumors showed hypodensity with slight to moderate enhancement., Conclusions: The malignant nonepithelial prostate tumors tended to have large sizes at presentation, have high FDG uptake, and affect a younger population with normal prostate-specific antigen levels. FDG PET/CT may be useful for the assessment of tumor grade and for detecting the distant metastases, whereas the MRI or enhanced CT may be more helpful for describing the relationship between the tumor and adjacent structures.

Aims: In this retrospective study, we evaluated the role of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) in differentiating malignant from benign portal vein thrombosis (PVT) in patients with known malignant tumors., Methods: Seventy-two patients with histologically or clinically confirmed PVT and who had undergone (18)F-FDG PET/CT were included. Visual and semiquantitative analyses of PET/CT scans were performed. Metabolic activity was measured using the maximum standardized uptake value (SUVmax) by drawing the region of interest at the site of thrombosis. Receiver operating characteristic analysis was conducted to identify the optimal cutoff of SUVmax for detecting neoplastic thrombosis. Malignancy was defined using the following criteria: (1) visual analysis and (2) SUVmax >3.35. PET/CT results were confirmed with histopathological results and clinical and imaging follow-up., Results: The SUVmax of tumor thrombus (6.37 ± 2.67) was significantly higher than that of bland thrombus (2.87 ± 1.47; P < 0.01). The sensitivities, specificities, and accuracies for the two criteria were 91.5 % and 93.6; 64.0 and 80.0 %; and 81.9 % and 88.9 %, respectively., Conclusion: (18)F-FDG PET/CT is a promising new method for distinguishing between portal venous neoplastic thrombosis and bland thrombosis using semiquantitative analysis, with the optimal cutoff value of SUVmax >3.35 as a criterion.

Splenic hamartomas are very rare benign vascular tumors. A 67-year-old man was referred after an incidental detection of a splenic lesion. Abdominal-enhanced CT showed a splenic lesion with progressive enhancement. This lesion showed intense FDG uptake with an SUVmax of 9.2. The patient underwent splenectomy. Splenic hamartoma was confirmed by pathologic evaluation. In this tumor, the disorganized splenic sinus contained a large amount of lymphocytes and plasma cells, which may contribute to the intense FDG uptake. This case indicates that splenic hamartoma should be included in the differential diagnosis of focal FDG accumulation along with tumor and nontumor conditions.

Spinal arachnoiditis is a disease characterized by inflammation and scarring of the arachnoid membrane of the spinal cord. FDG PET/CT findings of spinal arachnoiditis have been rarely reported. We present 3 cases of spinal infectious arachnoiditis (1 pyogenic and 2 tuberculous). MRI was performed in these 3 cases showing thickened spinal meninges with marked enhancement. FDG PET/CT was performed in 2 cases showing intense linear FDG uptake along the spinal canal. The combination of MRI and FDG PET/CT may be helpful in identifying the infectious sites and evaluating the activity of the infection.

Malignant fibrous histiocytoma primarily arising from the prostate is extremely rare. A 43-year-old man presented with dysuria for 12 months. Serum prostate-specific antigen level was normal. T2-weighted MR images showed a well-circumscribed tumor with inhomogeneous intensity in the prostate. The patient underwent transurethral resection of the prostate. Prostate malignant fibrous histiocytoma was histopathologically confirmed. FDG PET/CT was performed showing extremely high FDG uptake of the tumor with SUVmax of 46.8.

Tumor heterogeneity is used to define the appearance of different histological differentiation within a single neoplasm. We present a case of single hepatocellular carcinoma showing both low and high FDG uptake areas. The low FDG uptake area was corresponding to low-grade HCC, and the high FDG uptake area was corresponding to high-grade HCC. This case indicates that the tumor grades affect intratumoral heterogeneity in FDG distribution. FDG PET/CT can be useful for guiding tissue sampling of the HCC with heterogeneous histological differentiations, and obviating overestimation or underestimation of the proportion of the higher-risk cell population.

Peripheral primitive neuroectodermal tumor (pPNET) is a very aggressive neoplasm that predominantly affects children and adolescents with a poor prognosis. A 35-year-old woman presented with right upper abdominal pain for 2 weeks. Abdominal enhanced CT showed a large cystic-solid tumor in the left retroperitoneum, with progressive enhanced papillary projections of the wall. FDG PET/CT showed strong FDG uptake of the cystic wall with SUVmax of 17.2. The patient underwent completed resection of the tumor. pPNET was confirmed by pathology. The high FDG uptake of the tumor may be related to its high proliferative index revealed by Ki-67.

Primary basal cell carcinoma of the prostate is a very rare neoplasm with a good prognosis. A 55-year-old man presented with urinary frequency for 2 months. Serum prostate-specific antigen level was normal. T2-weighted MR images showed an inhomogeneously hyperintense tumor in the prostate. Enhanced CT showed heterogeneous enhancement of the tumor. FDG PET/CT showed strong FDG uptake of the tumor with SUVmax of 14.1. Prostate biopsy findings revealed basal cell carcinoma with high proliferation index.

Objective: Increased FDG uptake in the prostate can be caused by both benign and malignant conditions. The purpose of this pictorial review is to demonstrate a spectrum of prostate lesions which can show increased FDG uptake on PET/CT imaging., Conclusion: Various prostate lesions can show increased FDG uptake. Knowledge of the uptake characteristics of these lesions may be helpful for increasing diagnostic accuracy.

Objective: The purpose of this review is to describe FDG uptake characteristics of adrenal lesions, which can show increased FDG uptake on PET/CT., Conclusion: Both benign and malignant adrenal lesions can show increased FDG uptake. Knowledge of the uptake characteristics of these lesions is helpful for increasing diagnostic accuracy and expanding the differential diagnosis for adrenal lesions.

A 50-year-old woman presented with upper abdominal pain for 2 months. Abdominal enhanced CT showed multiple hypodense cystic tumors in the liver with heterogeneous enhanced septations. FDG PET/CT showed hypermetabolic peripheral regions and internal septations of the tumors with SUVmax of 6.3. Multiple hepatic cystadenocarcinomas were suspected. The patient underwent resection of the tumors. Epithelial mesothelioma was confirmed by pathology. This case indicates primary hepatic mesothelioma should be added to the differential diagnosis of FDG-avid malignant hepatic tumors.

Primary squamous cell carcinoma (SCC) of the prostate is a rare aggressive neoplasm with a poor prognosis. A 60-year-old man presented with urinary frequency and interrupted urination for 4 months. Serum prostate-specific antigen and SCC antigen were elevated. T2-weighted MR images showed a hyperintense lesion in the central area of the prostate. FDG PET/CT showed strong FDG uptake of the lesion with SUVmax of 15.5. Prostate biopsy revealed moderate differentiated SCC. This case indicates SCC of the prostate should be considered in the differential diagnosis of abnormal prostate FDG accumulation (especially with elevated SCC antigen level).

Follicular dendritic cell sarcoma (FDCS) is a rare neoplasm that originates from follicular dendritic cells. A 33-year-old woman was referred because of a 2-month history of lower abdominal fullness. Enhanced T1-weighted MR images showed enhancement of the thickened pelvic peritoneum. FDG PET/CT was performed showing multiple FDG-avid lymph nodes in the parapharyngeal, bilateral supraclavicular, left axillary, mediastinal, and abdominal regions, and intense FDG uptake in the thickened mesentery and peritoneum. Pathologic findings of both the left supraclavicular lymph node and peritoneal biopsy specimens were consistent with high-grade FDCS. In this case, extensive peritoneal involvement by FDCS was unusual.

A 37-year-old man presented with left upper abdominal pain for 13 months. Laboratory examinations showed elevated peripheral eosinophils. Chest CT showed thickened wall of the entire esophagus. FDG PET/CT was performed showing diffuse FDG uptake in the thickened esophageal wall. Esophageal endoscopy showed pale and edematous mucosa. Histologic examination of the esophageal biopsy specimens revealed marked eosinophil infiltration of the mucosa. The clinical and pathologic findings were consistent with eosinophilic esophagitis (EoE). This case indicates EoE should be included in the differential diagnosis of abnormal FDG accumulation in the esophageal wall along with malignant and nonmalignant conditions.

Metastasis to the bronchus from extrathoracic malignancy is a rare event. We present 2 cases of endobronchial metastases from extrathoracic tumors with FDG PET/CT findings. One patient had a hypermetabolic endobronchial metastasis from breast cancer. The other patient had a hypermetabolic endobronchial metastasis from hepatocellular carcinoma. Both the endobronchial metastases were confirmed by bronchoscopic biopsy. These 2 cases indicate that FDG PET/CT is useful for detecting endobronchial metastases, and endobronchial metastasis should be included in the differential diagnosis of abnormal endotracheal or endobronchial FDG accumulation in patients with histories of malignant tumors.

Serous psammocarcinoma of the ovary is a rare variant of ovarian serous carcinoma with a favorable prognosis. We present a case of bilateral ovarian serous psammocarcinoma showing extensive calcification in the primary and disseminated lesions with intense FDG uptake on FDG PET/CT. It may be difficult to differentiate the extensively calcified omental and peritoneal metastases from benign calcified lesions on CT images. This case indicates FDG PET/CT may have an advantage over conventional CT in differentiating malignant calcification from benign calcification based on glucose metabolic activity, and may be helpful for diagnosis and staging of this rare ovarian tumor.

Although some histological features of solitary fibrous tumor are related to its aggressive behavior, tumors with benign features may also follow an aggressive behavior. An 18-year-old male patient was referred after the detection of multiple bilateral pulmonary lesions on a chest x-ray in a health examination 2 months ago. These lesions showed inhomogeneous enhancement on enhanced CT and intense FDG uptake (SUVmax, 21.8) on PET/CT. CT-guided biopsy revealed histologically benign solitary fibrous tumor.

Pulmonary involvement of peripheral T-cell lymphoma is rare. It is difficult to make a clinical and radiologic diagnosis of pulmonary lymphomatous involvement, yet the diagnosis is often critical in determining treatment. We present 3 cases of pulmonary peripheral T-cell lymphoma with FDG PET/CT findings. In these 3 cases, FDG PET/CT images revealed multiple bilateral FDG-avid nodules, masses, or mass-like consolidations with or without air bronchogram. Familiarity with these imaging features may be helpful for the diagnosis and differential diagnosis.

Solitary necrotic nodule (SNN) of the liver is a rare benign lesion that can mimic malignancy. We present 3 cases of SNN with 18F-FDG PET/CT findings. In case 1, the SNN with complete necrosis and thin fibrous capsule appeared hypometabolic. In case 2, the SNN with a large amount of necrosis and irregular thickened wall appeared hypermetabolic in the periphery. In case 3, the SNN with a small amount of necrosis appeared hypermetabolic in the whole nodule. FDG PET/CT findings reflect the histopathological composition of SNN and its evolution stage.

Alveolar soft part sarcoma (ASPS) is a rare malignant soft tissue tumor. We present a case, who had a history of a left pulmonary ASPS resection 5 years ago, with a tumor in the left lower extremity showing high vascularity mimicking hemangioma on enhanced CT and MRI. This tumor showed intense FDG uptake on FDG PET/CT with SUVmax of 6.8, indicating a malignant soft tissue tumor. Complete resection of the tumor was performed. A diagnosis of ASPS was confirmed by pathology. This case highlights FDG PET/CT is helpful for differentiating ASPS from hemangioma according the degree of FDG uptake.

Intense FDG uptake of the mesenteric brown adipose tissue (BAT) is rare. We present a case of benign retroperitoneal pheochromocytoma showing multiple hypermetabolic regions corresponding with common locations of BAT. Furthermore, the mesenteric region showed intense FDG uptake, with SUVmax of 10.6. FDG PET/CT findings of this case supports the previous theories that the incidence of BAT may be higher in patients with pheochromocytoma than in patients without, and the intra-abdominal fat of human adults, including the omental fat, which is brown adipose tissue in infancy, becomes reactivated in the presence of high circulating noradrenaline concentrations.

Purpose: The aim of this study was to evaluate retrospectively F-FDG PET/CT findings of inflammatory myofibroblastic tumor (IMT) and their correlation with the pathologic findings., Patients and Methods: FDG PET/CT findings were reviewed in 5 patients with IMT and 1 patient with spindle cell sarcoma transformed from IMT. PET/CT scans were performed in all 6 patients before surgery. Follow-up FDG PET/CT scan was performed in 1 patient. The location, size, maximal standardized uptake value (SUVmax), and pathologic findings of the tumors were reviewed. The correlation between the FDG uptake and pathologic findings were analyzed., Results: A total of 10 lesions were detected in all 6 patients. The tumor locations were liver (n = 3), retroperitoneum (n = 2), spleen (n = 1), lung (n = 1), and bone (n = 3). Seven IMTs and 1 spindle cell sarcoma transformed from IMT were confirmed by pathology. The mean SUVmax of the pathologically proven tumors was 10.9 ± 5.5, with a high variability of SUVmax among tumors ranging from 3.3 to 20.8. The tumors (n = 7) with high cellularity had stronger FDG uptake, while the tumors (n = 1) with low cellularity had relatively low FDG uptake. The tumors with nuclear atypia and relatively high proliferative index had very strong FDG uptake, while those with low proliferative index or negative Ki-67 staining had relatively lower FDG uptake. One small tumor with abundant plasma cells showed high FDG uptake, while 1 large tumor with focal inflammatory cell infiltrate showed lower FDG uptake. One patient developed local recurrences and distant metastases revealed by the second FDG PET/CT scan 7 months after resection., Conclusions: FDG uptake in IMTs varied from low to high FDG uptake, which may be due to tumor cellularity, biological behaviors of the tumor cells, the composition and the proportion of inflammatory cells, and the extent of activation of the inflammatory cells. FDG PET/CT may be useful for detection of the primary tumors, local recurrences, and distant metastases.

Composite hemangioendothelioma (HE) is a recently described rare vascular neoplasm of low-grade malignancy. A 56-year-old man presented with sternum pain for 2 years. Bone scan showed a hot spot in the manubrium sterni. This lesion showed high signal intensity on T2-weighted MR images and high vascularity on enhanced T1-weighted MR images. F-FDG PET/CT showed increased FDG uptake of this osteolytic lesion with SUVmax of 5.9. Malignant tumor was suspected. The patient underwent resection of the lesion. Composite HE was confirmed by pathology.

Urachal inflammation is rarely seen in adults. Two patients with suspected abdominal tumor underwent FDG PET/CT. One patient showed an irregular hypermetabolic mass anterosuperior to the bladder. The other patient showed a thick-walled cystic mass with strong FDG uptake extending from the bladder dome to the anterior abdominal wall. Urachal carcinomas were suspected based on imaging findings. Both patients underwent complete resection of the masses. However, both masses were organized urachal abscesses confirmed by pathological examination. These two cases highlight that differentiation between organized urachal abscess and carcinoma is difficult on the basis of imaging.