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Abstract: Inflammatory variant of well-differentiated liposarcoma is a rare subtype of liposarcoma, and its imaging features have been rarely reported. We describe FDG PET/CT findings in a case of well-differentiated inflammatory liposarcoma. The tumor showed no detectable fat and intense FDG uptake and caused diffuse FDG uptake of the bone marrow due to paraneoplastic leukemoid reaction. Microscopically, there were extensive inflammatory infiltrates in the tumor, which may contribute to the intense FDG uptake. This case indicates that although well-differentiated liposarcoma usually shows low-grade FDG uptake, inflammatory variant of well-differentiated liposarcoma can show intense FDG uptake mimicking high-grade liposarcoma., Competing Interests: Conflicts of interest and sources of funding: none declared. Conflicts of interest and sources of funding: none declared. This work was supported by The Most Important Research Center Construction Project of Shanghai (grant 2022ZZ01011)., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: A 23-year-old woman presenting with gross hematuria was found to have a left renal mass suspicious for renal cell carcinoma on abdominal contrast-enhanced CT. An 18 F-PSMA-1007 PET/CT scan was performed for evaluating the renal mass. 18 F-PSMA-1007 PET/CT showed focal activity of the renal mass, which was a transcription factor E3-rearranged renal cell carcinoma proved after nephrectomy. Surprisingly, diffuse heterogeneous intense activity of the bilateral breasts and moderate activity of the right accessory breast was observed. There was no morphological abnormality of the bilateral breasts and right accessory breast on CT images, indicating physiological PSMA uptake., Competing Interests: Conflicts of interest and sources of funding: This work was supported by the “Discipline Climbing 234 Plan For Disciplinary Platform Construction” of The First Affiliated Hospital of Naval Medical University (no. 2020YPT002) and The First Affiliated Hospital of Naval Medical University “Guhai Plan in the 14th Five-Year Plan Period” (grant no. GH145-22 and GH145XKQ-03)., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Solitary fibrous tumor arising from the seminal vesicle is very rare. We describe 18 F-PSMA-1007 PET/CT findings in a case of prostate adenocarcinoma with a solitary fibrous tumor of the left seminal vesicle. The solitary fibrous tumor showed intense 18 F-PSMA-1007 uptake mimicking metastatic prostate adenocarcinoma. This case indicates that solitary fibrous tumor may cause false-positive result when using PSMA PET in staging of prostate cancer., Competing Interests: Conflicts of interest and sources of funding: none declared. Conflicts of interest and sources of funding: The authors have no conflicts of interest to declare. This work was supported by “234 Discipline Climbing Plan” of the First Affiliated Hospital of Naval Medical University (grant no. 2019YPT002 and 2020YPT002) and The First Affiliated Hospital of Naval Medical University (Shanghai Changhai Hospital) “Guhai Plan in the 14th Five-Year Plan Period” (grant no. GH145XKQ-03)., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: A 64-year-old man was referred for 18 F-PSMA-1007 PET/CT scan for initial staging of biopsy-proved prostate adenocarcinoma. 18 F-PSMA-1007 PET/CT showed focal intense 18 F-PSMA-1007 of the prostate adenocarcinoma and a focal intense activity with SUV max of 10.5 in the left ilium. The 18 F-PSMA-1007-avid iliac bone lesion corresponded to a hemangioma, which was initially detected on pelvic MRI 13 months ago and remained stable in size. This case indicates that hemangioma should be included in the differential diagnosis of PSMA-avid iliac bone lesions., Competing Interests: Conflicts of interest and sources of funding: none declared. This work was supported by “234 Discipline Climbing Plan” of the First Affiliated Hospital of Naval Medical University (grant no. 2019YPT002 and 2020YPT002) and The First Affiliated Hospital of Naval Medical University (Shanghai Changhai Hospital) “Guhai Plan in the 14th Five-Year Plan period” (grant no. GH145XKQ-03)., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: A 46-year-old man underwent PET/CT for metastatic survey 6 years after radical resection of pancreatic cancer. In addition to the increased uptake observed in the operative area, increased FDG uptake was also observed in the left external abdominal oblique muscle and the left frontal scalp. Both intramuscular and subcutaneous lesions were surgically excised and diagnosed as metastases from pancreatic cancer., Competing Interests: Conflicts of interest and sources of funding: This work is supported by the “234 Discipline Climbing Plan” of the First Affiliated Hospital of Naval Medical University (grant no. 2019YPT002 and 2020YPT002). The authors have no conflicts to report., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Primary angiosarcoma of the kidney is a rare aggressive malignancy. We describe MRI and FDG PET/CT findings in a case of primary renal angiosarcoma with hepatic, pulmonary, and bony metastases. The large primary tumor showed extensive necrosis and increased FDG uptake in the nonnecrotic components. Multiple metastatic lesions in the liver, lung, and bones were detected by FDG PET/CT. Most of the hepatic metastases seen on MRI were missed on FDG PET/CT due to low FDG avidity., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: We aimed to evaluate whether [ 68  Ga]Ga-FAPI-04 PET/CT could characterize the early stages of cardiac fibrosis in pressure overload heart failure., Methods: Sprague-Dawley rats underwent abdominal aortic constriction (AAC) (n = 12) and sham surgery (n = 10). All rats were scanned with [ 68  Ga]Ga-FAPI-04 PET/CT at 2, 4, and 8 weeks after surgery. The expression of fibroblast activation protein (FAP) in the myocardium was detected by immunohistochemistry. [ 68  Ga]Ga-FAPI-04 PET signal and FAP expression were compared between two groups., Results: Compared with the sham group, the AAC group presented with decreased ejection fraction (EF) and fractional shortening (FS) and increased left ventricular internal dimensions in diastole (LVIDd) and systole (LVIDs) at 4 and 8 weeks (all p < 0.01). The AAC group showed higher [ 68  Ga]Ga-FAPI-04 accumulation in the heart than the sham group at 2, 4, and 8 weeks, and FAPI increased significantly from 2 to 8 weeks (all p < 0.001). Immunohistochemistry confirmed the higher density of the FAP + area in the AAC group. The intensity of the [ 68  Ga]Ga-FAPI-04 correlated with the density of the FAP + area (p < 0.001). The expression of the [ 68  Ga]Ga-FAPI-04 at 4 weeks correlated with the deterioration of cardiac function at 8 weeks (EF: R =  - 0.87; FS: R =  - 0.72; LVIDd: R = 0.77; LVIDs: R = 0.79; all p < 0.001). The AAC group also showed an increased [ 68  Ga]Ga-FAPI-04 signal in the liver, peaking at 4 weeks and then declining. Cardiac and liver PET signals correlated at 4 weeks in the AAC group (R = 0.69, p = 0.0010), suggesting an early fibrotic link between organs. A combination of the [ 68  Ga]Ga-FAPI-04 intensity in the heart and liver at 4 weeks better predicted the deterioration of cardiac function at 8 weeks., Conclusions: The activated fibroblasts in the heart and liver after pressure overload can be monitored by [ 68  Ga]Ga-FAPI-04 PET/CT, which reveals an early fibrotic link in cardio-liver interactions and could better predict nonischemic heart failure prognosis., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Abstract: A 65-year-old man presented with abdominal bloating for approximately 4 weeks. After CT imaging, it was diagnosed as gastric carcinoma with hepatic metastasis. 68Ga-FAPI-04 PET/CT revealed much higher tumor-to-background contrast and more metastatic lesions compared with 18F-FDG PET/CT in this case. Following gastroscopy and pathological examination, the final diagnosis was malignant gastrointestinal stromal tumor. This case demonstrated that 68Ga-FAPI-04 PET/CT was more sensitive than 18F-FDG PET/CT for detecting primary and metastatic lesions in malignant gastrointestinal stromal tumor., Competing Interests: Conflicts of interest and sources of funding: The authors declare that they have no conflicts of interest. This work was supported by the “234 Discipline Climbing Plan” of the First Affiliated Hospital of Naval Medical University (grant 2019YPT002, and 2020YPT002)., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

68Ga-prostate specific membrane antigen (PSMA)-11 PET/CT has been widely used in the diagnosis of prostate cancer (PCa); however, the urine lead shielding resulting from the urinary metabolism of tracers may obstruct the detection of surrounding metastasis. In this research, the additive value of super early scanning in diagnosing primary lesions and metastasis in the pelvic cavity was evaluated. Firstly, the differentiation efficiency of 68Ga-PSMA-11 PET scanned at 3 min post-injection (min P.I.) was measured in PSMA-positive (22rv1 cells) and PSMA-negative (PC3 cells) model mice. Secondly, 106 patients were scanned at 3 min P.I. for the pelvic cavity and then scanned as a standard protocol at 45 min P.I. In the results, the differential diagnosis of PSMA expression was completely reflected as early as 3 min P.I. for mice models. For patients, when correlated with the Gleason score, the quantitative results of the super early scan displayed a comparable correlation coefficient with the routine scan. The target to bladder ratios increased from 1.44 ± 2.40 at 45 min to 10.10 ± 19.10 at 3 min (p < 0.001) for the primary lesions, and it increased from 0.99 ± 1.88 to 9.27 ± 23.03 for metastasis. Meanwhile, the target to background ratios increased from 2.21 ± 2.44 at 3 min to 19.13 ± 23.93 at 45 min (p < 0.001) for the primary lesions, and it increased from 1.68 ± 2.71 to 12.04 ± 18.73 (p < 0.001) for metastasis. In conclusion, super early scanning of 68Ga-PSMA-11 PET/CT added referable information for metastasis detection in order to avoid disturbing tracer activity in the urinary system.

Purpose: We aimed to analyze the change of quantitative intra-tumoral metabolic heterogeneity consisting of texture features and conventional metabolic parameters of pancreatic cancer (PC) in dual-time 2-deoxy-2( 18 F) fluoro-D-glucose ( 18 F-FDG) positron emission tomography-computed tomography (PET/CT)., Methods: A retrospective analysis was conducted considering the texture features and conventional metabolic parameters in dual-time 18 F-FDG PET/CT scans of PC patients. Features were extracted based on spatial distribution of 18 F-FDG uptake in image. Firstly, the texture features and the conventional metabolic parameters of the delayed scan were both compared with that of the early scan. Statistically different data was defined among them. Secondly, the study evaluated the correlations between retention index (RI) of the texture features and the conventional metabolic parameters. Finally, the variation of texture features in dual-time PET/CT of resectable PC patients and unresectable PC patients was calculated separately., Results: In total, 183 PC patients were analyzed retrospectively in this research. The conventional metabolic parameters were all statistically different between the early and delayed scans except for metabolic tumor volume (MTV). In the radiomics, there were 59 textural features. Nineteen of 59 texture features were statistically different between the early and delayed scans. Features that were more than 10% different during two scans were observed in a substantial percentage of patients. Weak correlations were only found between MTV, TLG (Total lesion glycolysis), SUVpeak and the RI of some texture features in early or delayed scans. There were obviously fewer features with significant difference in resectable PC group than in unresectable PC group. Most features showing the difference in unresectable group while no significant difference in resectable group., Conclusions: This study investigated the change and inner correlations of quantitative tumoral metabolic heterogeneity in the dual-time 18 F-FDG-PET/CT scan of PC patients. Some features displayed the difference between dual-time scans. Conventional metabolic parameters were weakly related to the change of texture feature. The change of texture feature in resectable PC group was different from that in unresectable PC group. This result is potential to provide more information for the image evaluation of PC., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Abstract: Significant 68Ga-PSMA-11 activity is commonly observed in the lacrimal and salivary glands on PSMA PET/CT. An 80-year-old man after radical prostatectomy was evaluated with 68Ga-PSMA-11 PET/CT. There was no obvious PSMA uptake in the bilateral lacrimal, parotid, and submandibular glands. Subsequently, based on laboratory examination results and 99mTcO4 salivary gland scintigraphy, this patient was diagnosed with Sjögren syndrome, which accounted for the absence of uptake by the glands. This case showed the potential of 68Ga-PSMA-11 PET/CT in the evaluation of the lacrimal glands and major salivary glands., Competing Interests: Conflicts of interest and sources of funding: This work was supported by the “Discipline Construction Climbing 234 Plan” of Changhai Hospital of Naval Medical University (Second Military Medical University) (no. 2019YPT002) and Shanghai Advanced Appropriate Technology Promotion Projects (no. 2019SY029). None declared to all authors., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

OBJECTIVE. The purpose of this article is to investigate the value of 18 F-FDG PET/CT and enhanced CT in the diagnosis of renal cell carcinoma (RCC) with sarcomatoid differentiation and the differential diagnosis of clear cell renal cell carcinoma (ccRCC). MATERIALS AND METHODS. Among patients with renal tumors confirmed by pathologic examination from September 2010 to August 2019, 29 patients with RCC with sarcomatoid differentiation and 82 patients with ccRCC who underwent FDG PET/CT, renal contrast-enhanced CT examination, or both, before surgery were studied. Features of the two groups on CT and PET/CT were retrospectively reviewed. RESULTS. The tumor size of RCC with sarcomatoid differentiation was larger than that of ccRCC ( p = 0.0086). Cystic necrosis, peritumoral neovascularity, and metastasis were more common in RCC with sarcomatoid differentiation ( p = 0.0052, p = 0.0008, p < 0.0001, respectively). The ratio of necrotic area to tumor diameter of RCC with sarcomatoid differentiation was statistically significantly larger than that of ccRCC ( p = 0.0032). Three cases of RCC with sarcomatoid differentiation showed a large central necrotic area and dense intratu-moral neovascularity in the surrounding parenchyma, defined as the ring-of-fire sign, which was not found in ccRCC. The maximum standardized uptake value (SUV max ), mean standardized uptake value (SUV mean ), and peak standardized uptake value (SUV peak ) of RCC with sarcomatoid differentiation were statistically significantly higher than those for ccRCC (all p < 0.0001), and the SUV max , SUV mean , and SUV peak cutoff values of 5.4, 4.2, and 5.0, respectively, were helpful for discrimination. CONCLUSION. Imaging features including higher SUV max , SUV mean , and SUV peak ; a larger ratio of necrotic area to tumor diameter; the presence of peritumoral neovascularity; and metastasis are more commonly associated with RCC with sarcomatoid differentiation than with ccRCC. The ring-of-fire sign and SUV max , SUV mean , SUV peak cutoff values of 5.4, 4.2, 5.0, respectively, may be helpful to indicate RCC with sarcomatoid differentiation.

Objective: To explore standardized relative thresholds of volume-based parameters on FDG PET/CT, and define the optimal prognosticator among the relative thresholds for patients with locally advanced pancreatic head cancer (LAPHC) treated by stereotactic body radiation therapy (SBRT)., Methods: Thirty-five patients with LAPHC were enrolled, and all underwent SBRT and baseline FDG PET/CT scan. Maximum standardized uptake value (SUVmax) was measured, and metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were calculated under the relative (30%, 40%, and 50%) thresholds of SUVmax. Survival analysis was performed via univariate and multivariate analyses, and independent prognostic factors were determined by Cox proportional hazard models and corresponding survival curves and scatter diagram were drawn., Results: The median overall survival (OS) and progression-free survival (PFS) were 13.8 and 9.8 months, respectively. On univariate analysis, MTV(40%) < 5.6 cm 3 , accumulated dose (AD) ≥ 36 Gy and the absence of pancreatic duct (PD) stents were significantly correlated with both superior OS and PFS, TLG (40%) < 29.9 was related to better OS and biological effective dose (BED 10 ) ≥ 57.6 Gy was related to better PFS (all with p < 0.05). Further, multivariate analysis demonstrated both MTV (40%) and AD were independent prognosticators for OS and PFS, and BED 10 was an independent predictor for PFS (all with p < 0.05). Scatter diagram showed BED 10 to be a stronger clinical prognosis predictor for PFS than AD., Conclusions: MTV (40%) was the optimal prognosticator among the relative thresholds of SUVmax for tumor delineation on PET/CT for LAPHC patients receiving SBRT. AD was also favorable indicators for OS and PFS of patients, and BED 10 was more sensitive than AD in predicting the PFS of patients.

We present 2 cases of pancreatic neuroendocrine tumor with diffuse involvement of the entire pancreas. One case with G2 pancreatic neuroendocrine tumor showed nearly normal pancreatic shape and signal intensity on MRI, normal pancreatic FDG uptake, and diffuse pancreatic Ga-DOTATOC uptake. The other case with G3 pancreatic neuroendocrine tumor showed diffusely enlarged pancreas with abnormal MR signal intensity and increased FDG uptake. These 2 cases indicate that neuroendocrine tumor should be included in the differential diagnosis of diffuse pancreatic diseases. Somatostatin receptor imaging may be helpful for the diagnosis of diffuse pancreatic neuroendocrine tumor in equivocal cases.

Background: 18 F-FDG PET/CT metabolic parameters have been applied as prognostic factors in multi-malignancies. However, the role in locally advanced pancreatic cancer (LAPC) was not confirmed. In this study, we investigated the prognostic value of 18 F-FDG PET/CT metabolic parameters in LAPC patients treated with stereotactic body radiation therapy (SBRT)., Methods: Seventy three LAPC patients who received SBRT therapy and pre-treatment 18 F-FDG PET/CT imaging from January 2012 to January 2016 were included in this retrospective study. The study aim was to evaluate the relationship between metabolic parameters with clinical factors, and the value of metabolic parameters in the prognosis of LAPC. The median of parameters was set as the cut-off value for statistical analysis. Univariate survival analysis was performed by the Kaplan Meier method and log-rank test, and multivariate analysis was carried out by a Cox proportional hazards model., Results: Patients with lymph node metastasis or longer tumor diameters were associated with higher TLG (P < 0.05). Univariate analysis showed MTV, TLG, radiotherapy dose and chemotherapy were significantly associated with disease progression-free survival (PFS) and overall survival (OS) (P < 0.05). Lymph node metastasis and tumor longest diameter were associated with OS. Multivariate analysis demonstrated TLG, radiotherapy dose, and chemotherapy were independent factors of PFS and OS (HR: 2.307, 0.591, 0.572 and 2.145, 0.480, 0.471, P < 0.05)., Conclusions: TLG was found to be the independent prognostic factor of OS and PFS. Among clinical factors, radiotherapy dose and chemotherapy were independent prognostic factors of OS and PFS.

Purpose: To investigate 18 F-FDG PET/CT feature of pancreatic adenosquamous carcinoma (PASC) in contrast with conventional pancreatic ductal adenocarcinoma (PDAC), and its correlation with pathological findings., Patients and Methods: Patients with PASC or PDAC confirmed by surgical pathology, who underwent FDG PET/CT scanning before surgical resection, were retrospectively studied. PASC group and conventional PDAC group included 13 and 104 patients, respectively. Delayed phase of PET/CT scanning was performed in 12 patients with PASC and 99 with PDAC. Maximum standardized value (SUVmax) was measured, and the mean retention index (RI) was calculated by ([PET 120min SUVmax]-[PET 60min SUVmax]) ÷ PET 60min SUVmax × 100%., Results: On PET/CT, all lesions of PASC group showed intense FDG uptake, and the SUVmax were significantly higher than the lesions of conventional PDAC group both on the early [10.43 ± 5.10 (4.37-24.00) vs. 7.31 ± 3.86 (1.93-21.08), P = 0.011] and delayed phase [13.29 ± 6.04 (5.72-28.16) vs. 8.84 ± 5.14 (1.92-27.58), P = 0.005]. On the delayed phase, all lesions of PASC group had increased SUVmax with positive RI value (27.04% ± 8.87%, 7.14-39.27%). For conventional PDAC group, 81 lesions had increased SUVmax with positive RI value (27.25% ± 19.10%, 1.09-104.49%), while eighteen (18.18%) lesions of PDAC group had slightly decreased SUVmax, and their RI value were negative (- 11.35% ± 13.50%, - 43.17 to - 0.14%). The proliferative index (Ki-67) of lesions of PASC group was positively correlated with both the early (P = 0.034, r = 0.671) and delayed SUVmax (P = 0.019, r = 0.721). The RI value of lesions with adjacent organ invasion in PASC group was significantly higher than those without invasion (33.25% ± 4.92% vs. 20.83% ± 7.49%, P = 0.007)., Conclusion: PASC has more intense FDG uptake than conventional PDAC both on early and delayed phase. RI value of PASC was positive. Negative RI value may be helpful for differentiating PDAC from PASC. SUVmax and RI value may be helpful for prediction of its malignancy and invasion.

Purpose: To establish an accurate and reliable equation for kidney depth estimation in adult patients from different Chinese geographical regions., Method: This multicenter study enrolled Eastern Asian Chinese patients with abdominal PET/CT scans at 26 imaging centers from six macro-regions across China in 3 years. Age, gender, height, weight, primary disease and its extent on PET scans of the participants were collected as potential predictive factors. Kidney depth on CT, defined as the average of the vertical distances from the posterior skin to the farthest anterior and closest posterior surfaces of each kidney, was measured as the standard reference. The new kidney depth model was constructed using a multiple regression model, and its performance was compared to those of three established models by computing the absolute value of estimation errors in comparison with CT-measured kidney depth., Results: A total of 2502 patients were enrolled and classified into training (n=1653) and testing (n = 849) subsets. In the training subset, two kidney depth models were constructed: Left (cm): 0.013×age+0.117×gender-0.044×height+0.087×weight+7.951, Right (cm): 0.005×age+0.013×gender-0.035×height+0.082×weight+7.266 (weight: kg, height: cm, gender = 0 if female, 1 if male). In the testing subset, one-way analysis of variance showed that the estimation errors of the new models did not significantly differ among the 6 regions. Bland-Altman analysis determined that new equations had lower estimated biases (left: 0.039 cm, right: 0.018 cm) compared with other existing models., Conclusion: The new equations were highly accurate for kidney depth estimation in adults from all over China, with lower estimation errors compared to other established models., Competing Interests: Declaration of Competing Interest None., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Purpose: To perform a radiomics analysis with comparisons of multidomain features and a variety of feature selection strategies and classifiers, with the goal of evaluating the value of quantified radiomics method for noninvasively differentiating autoimmune pancreatitis (AIP) from pancreatic ductal adenocarcinoma (PDAC) in 18 F-fluorodeoxglucose positron emission tomography/computed tomography ( 18 F FDG PET/CT) images., Methods: We extracted 251 expert-designed features from 2D and 3D PET/CT images of 111 patients, and recombined these features into five feature sets according to their modalities and dimensions. Among the five feature sets, the optimal one was found leveraging four feature selection strategies and four machine learning classifiers based on the area under the receiver operating characteristic curve (AUC). The feature selection strategies include spearman's rank correlation coefficient, minimum redundancy maximum relevance, support vector machine recursive feature elimination (SVM-RFE), and no feature selection, while the classifiers are random forest, adaptive boosting, support vector machine (SVM) with the Gaussian radial basis function, and SVM with the linear kernel function respectively. Based on the optimal feature set, these feature selection strategies and classifiers were comparatively studied to achieve the best differentiation. Finally, the quantified radiomics prediction model was developed based on the best combination of the feature selection strategy and classifier, and it was compared with two clinical factors based prediction models, and human doctors using nested cross-validation in terms of AUC, accuracy, sensitivity, and specificity., Results: Comparison experiments demonstrated that CT features and three-dimensional (3D) features performed better than positron emission tomography (PET) features and three-dimensional (2D) features respectively, and multidomain features were superior to single domain features. In addition, the combination of SVM-RFE feature selection strategy and Linear SVM classifier had the highest diagnostic performance (i.e., AUC = 0.93 ± 0.01, ACC = 0.85 ± 0.02, SEN = 0.86 ± 0.03, SPE = 0.84 ± 0.03). The quantified radiomics model developed is significantly superior to both human doctors and clinical factors based prediction models in terms of accuracy and specificity., Conclusions: Our preliminary results confirmed that the quantified radiomics method could aid the noninvasive differentiation of AIP and PDAC in 18 F FDG PET/CT images and the integration of multidomain features is beneficial for the differentiation., (© 2019 American Association of Physicists in Medicine.)

Cat scratch disease (CSD) is a rare zoonotic infection disease, and the imaging performance for evaluation varies. We present FDG PET/CT images of two cases of CSD. In one case, images showed typical findings of regional lymph node enlargement. In another case, images showed atypical findings of extensive superficial and deep lymph node enlargement.

Stereotactic body radiation therapy (SBRT) has emerged to be a preference treatment for locally advanced pancreatic cancer (LAPC) patients. In this study, we aimed to investigate the prognostic roles of F-FDG PET/CT metabolic parameters and clinical figures in LAPC patients underwent chemo-SBRT combined therapy.During January 2013 to January 2017, 23 LAPC patients who underwent F-FDG PET/CT within 2 weeks before treatment were recruited and retrospectively analyzed. Maximum standardized uptake values (SUVmax), SUVmean, metabolic tumor volume (MTV), total lesion glycolysis (TLG), chemoradiotherapy (CRT) sequence, and relevant clinical figures were grouped upon the median values, then analyzed by Kaplan-Meier method and Cox proportional hazard models for their prognostic evaluation.The median overall survival (OS) and progression-free survival (PFS) of all patients were 16.7 months and 11.3 months, respectively. According to the statistic results, the longest diameter of tumor (LDT), MTV, TLG, and CRT sequence were associated with OS (all P <.05). Among which, LDT and MTV were proved to be the independent prognostic factors for OS (hazard ratio [HR]: 3.437, 3.015, both P <.05). Additionally, LDT and CRT sequence were found associated with PFS (both P <.05), and CRT sequence was the independent prognostic factor for PFS in chemo-SBRT treated LAPC patients (HR: 0.130, P <.05).For LAPC patients received chemotherapy and SBRT combined therapy, MTV and LDT showed independent prognostic values for OS. Meanwhile, CRT sequence was an independent PFS prediction factor.

A 49-year-old woman complained of right upper back pain for 1 month. Serum tests showed increased erythrocyte sedimentation rate. Thoracic spinal MRI showed an epidural lesion at the T1-T4 level with inhomogeneous signal intensity on T2-weighted images, slightly higher signal intensity than spinal cord on T1-weighted images, and remarkable enhancement on enhanced T1-weighted images. Epidural malignant tumor was suspected. FDG PET/CT was performed showing increased FDG uptake of the lesion extending to the right T1-T2 and T2-T3 neural foramina. A decompressive posterior thoracic laminectomy with the lesion resection was performed. Immunoglobulin G4-related spinal hypertrophic pachymeningitis was confirmed by pathology.

Clinically, renal metastasis from esophageal squamous cell carcinoma is uncommon. We present 2 cases of renal metastasis from esophageal squamous cell carcinoma with enhanced CT and FDG PET/CT findings. In the first case, right kidney and right renal hilum were the only known metastatic sites. In the second case, bilateral kidneys were the only known metastatic sites. All the renal metastatic tumors appeared as hypovascular and hypoattenuating masses involving both the renal cortex and medulla on enhanced CT and intense FDG uptake on FDG PET/CT.

Background: 18 F-FDG PET/CT could satisfactorily show pancreatic and extra-pancreatic lesions in AIP, which can be mistaken for pancreatic cancer (PC). This study aimed to identify 18 F-FDG PET/CT findings that might differentiate AIP from PC., Methods: FDG-PET/CT findings of 26 AIP and 40 PC patients were reviewed. Pancreatic and extra-pancreatic lesions related findings, including maximum standardized uptake values (SUVmax) and patterns of FDG uptake, were identified and compared., Results: All 26 patients with AIP had increased pancreatic FDG uptake. Focal abnormal pancreatic FDG activities were found in 38/40 (95.00%) PC patients, while longitudinal were found in 18/26 (69.23%) AIP patients. SUVmax was significantly different between AIP and PC, both in early and delayed PET/CT scans (p < 0.05). AUCs were 0.700 (early SUVmax), 0.687 (delayed SUVmax), 0.683 (early lesions/liver SUVmax), and 0.715 (delayed lesion/liver SUVmax). Bile duct related abnormalities were found in 12/26 (46.15%) AIP and 10/40 (25.00%) PC patients, respectively. Incidentally, salivary and prostate gland SUVmax in AIP patients were higher compared with those of PC patients (p < 0.05). In males,an inverted "V" shaped high FDG uptake in the prostate was more frequent in AIP than PC patients (56.00%, 14/25 vs. 5.71%, 2/35). Increased FDG activity in extra-pancreatic bile duct was present in 4/26 of AIP patients, while was observed in none of the PC patients. Only in AIP patients, both diffuse pancreatic FDG accumulation and increased inverted "V" shaped FDG uptake in the prostate could be found simultaneously., Conclusions: 18 F-FDG PET/CT findings might help differentiate AIP from PC.

Primary splenic angiosarcoma is rare. A 44-year-old man presented with abdominal distension and malaise for 7 months. Laboratory tests showed anemia. Abdominal ultrasound showed enlargement of the spleen with multiple hypoechoic nodules. These nodules showed progressive enhancement on dynamic enhanced CT. Lymphoma was suspected. FDG PET/CT showed increased nonuniform FDG uptake with SUVmax of 11.6 of the entire spleen. Laparoscopic splenectomy was performed. The pathologic findings were consisted with angiosarcoma with replacement of the spleen. Eight months after surgery, multiple hepatic metastases were detected by follow-up abdominal CT.

A 46-year-old man with over a 10-year history of gout complained of progressive bilateral buttock pain with numbness of legs for 4 months. Serum uric acid level was elevated. Lumbar radiographs showed decreased density of the bilateral L4-L5 facet joints. CT showed lytic lesions of the facet joints with hyperdense periarticular lesions. Enhanced MRI showed marked enhancement of these lesions. FDG PET/CT showed avid FDG uptake of the bony and periarticular lesions with SUVmax of 16.8. A decompressive posterior lumbar laminectomy with periarticular lesion resection was performed. Histopathologic findings of the periarticular lesions were consistent with tophaceous gout.

Primary renal collecting duct carcinoma is an extremely rare neoplasm. We present a case of preoperative collecting duct carcinoma with enhanced MRI and F-FDG PET/CT findings. The MRI and PET imaging showed a round mass in the left kidney, as well as multiple retroperitoneal lesions with slight enhancement and intense FDG uptake, respectively. A left radical nephrectomy was performed. Primary renal collecting duct carcinoma and retroperitoneal lymph node metastases were confirmed histopathologically.

IgG4-related peripulmonary arteritis is rare. A 60-year-old woman presented with fatigue for more than 2 years. Transthoracic echocardiography revealed a lesion measuring 2.1 × 1.5 cm in the pulmonary artery bifurcation. CT pulmonary angiography showed marked stenosis of the right and left pulmonary arteries. FDG PET/CT showed increased FDG uptake of the thickened walls in the bilateral pulmonary arteries with SUVmax of 5.8. The patient underwent partial resection of the pulmonary artery lesion. IgG4-related peripulmonary arteritis was confirmed by pathology.

We present a case of 64-year-old man with primary central nervous system lymphoma that mimicked encephalitis on enhanced MRI and F-FDG PET/CT imaging. The initial and follow-up MRI showed gradually spread high-intensity patches with nonenhancement in cortices and subcortices, while the F-FDG imaging observed mild and inhomogeneous uptake in the corresponding cerebral area particularly in the splenium of corpus callosum. This case indicates that atypical primary central nervous system lymphoma should be noted in differential diagnosis of cerebral disseminated lesions with nonenhancement in MRI or with obscure uptake of F-FDG in PET imaging (especially involving the midline of the brain).

Aim: To compare (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) features in gastric lymphoma and gastric carcinoma., Methods: Patients with newly diagnosed gastric lymphoma or gastric carcinoma who underwent (18)F-FDG PET/CT prior to treatment were included in this study. We reviewed and analyzed the PET/CT features of gastric wall lesions, including FDG avidity, pattern (focal/diffuse), and intensity [maximal standard uptake value: (SUVmax)]. The correlation of SUVmax with gastric clinicopathological variables was investigated by χ(2) test, and receiver-operating characteristic (ROC) curve analysis was performed to determine the differential diagnostic value of SUVmax-associated parameters in gastric lymphoma and gastric carcinoma., Results: Fifty-two patients with gastric lymphoma and 73 with gastric carcinoma were included in this study. Abnormal gastric FDG accumulation was found in 49 patients (94.23%) with gastric lymphoma and 65 patients (89.04%) with gastric carcinoma. Gastric lymphoma patients predominantly presented with type I and type II lesions, whereas gastric carcinoma patients mainly had type III lesions. The SUVmax (13.39 ± 9.24 vs 8.35 ± 5.80, P < 0.001) and SUVmax/THKmax (maximal thickness) (7.96 ± 4.02 vs 4.88 ± 3.32, P < 0.001) were both higher in patients with gastric lymphoma compared with gastric carcinoma. ROC curve analysis suggested a better performance of SUVmax/THKmax in the evaluation of gastric lesions between gastric lymphoma and gastric carcinoma in comparison with that of SUVmax alone., Conclusion: PET/CT features differ between gastric lymphoma and carcinoma, which can improve PET/CT evaluation of gastric wall lesions and help differentiate gastric lymphoma from gastric carcinoma., Competing Interests: Conflict-of-interest statement: The authors declare no conflict of interest related to this study.

Ménétrier disease is a very rare chronic gastric disorder characterized by gastric mucosal hypertrophy. We present a case of Ménétrier disease with CT, MRI, and FDG PET/CT findings. Enhanced CT and MRI showed diffuse thickened mucosa of the greater curvature and elongated mucosa of the antrum with remarkable enhancement. The early and delayed FDG PET/CT showed increased FDG uptake of these thickened mucosa. The increased FDG uptake may be due to the mucosal inflammation. This case indicates Ménétrier disease should be included in the differential diagnosis of abnormal gastric FDG accumulation along with tumor and nontumor processes.

Interpretation of F-FDG PET/CT studies in breast is challenging owing to nonspecific FDG uptake in various benign and malignant conditions. Benign conditions include breast changes in pregnancy and lactation, gynecomastia, mastitis, fat necrosis, fibroadenoma, intraductal papilloma, and atypical ductal hyperplasia. Among malignancies, invasive ductal carcinoma and invasive lobular carcinoma are common histological types of breast carcinoma. Rarely, other unusual histological types of breast carcinomas (eg, intraductal papillary carcinoma, invasive micropapillary carcinoma, medullary carcinoma, mucinous carcinoma, and metaplastic carcinoma), lymphoma, and metastasis can be the causes. Knowledge of a wide spectrum of hypermetabolic breast lesions on FDG PET/CT is essential in accurate reading of FDG PET/CT. The purpose of this atlas article is to demonstrate features of various breast lesions encountered at our institution, both benign and malignant, which can result in hypermetabolism on FDG PET/CT imaging.

Primary uterine non-Hodgkin's lymphoma of the cervix is rare. We report a 31-year-old woman presented with menolipsis for 8 weeks. Transvaginal ultrasonography and pelvic MRI detected a solid cervical mass invading the adjacent vaginal wall. The lesion showed obvious FDG uptake on PET/CT scan, and malignancy was considered. It proved to be primary diffuse large B-cell lymphoma of the cervix by biopsy. After 6-cycle R-CHOP chemotherapy, no abnormal FDG uptake was found on another FDG PET/CT scan.

Splenic ameboma (amebic granuloma) is rare. A 38-year-old man with a severe pneumonia due to inhalation of swimming pool water 18 months ago complained of night sweat, tiredness, and anorexia for 1 month. Abdominal ultrasound showed multiple nodules in the spleen. These nodules showed slight enhancement on enhanced CT and intense FDG uptake on PET/CT. Splenectomy was performed. Multiple splenic amebomas were confirmed by pathology. Free-living amoebae were also detected in samples of pleural effusion and blood. Splenic ameboma, although rare, should be included in the differential diagnosis with isolated focally increased FDG activity in the spleen.

Aim: To investigate computed tomography (CT), magnetic resonance imaging (MRI), and combined 2-[18F]-fluoro-2-deoxy-d-glucose (18F-FDG) positron-emission tomography (PET)/CT features of pancreatic sarcomatoid carcinoma (PSC).Materials and Methods: The hospital database was searched retrospectively for the patients with PSC confirmed at histopathology after surgery. Ten patients who underwent unenhanced and enhanced CT (n=4), unenhanced and enhanced MRI (n=2), 18F-FDG PET/CT (n=2), and both enhanced CT and 18F-FDG PET/CT (n=2) were enrolled. Two patients underwent additional delayed PET/CT. The maximum standardised uptake value (SUVmax) was measured on PET/CT images.Results: Eleven lesions were detected in 10 patients. Solid and cystic components (n=6), intratumoural haemorrhage (n=1), nodular calcification (n=2), main pancreatic duct dilatation resulted from lesion obstruction (n=5) or compression (n=3), cholangiectasis (n=5), vascular and peripheral organ invasion (n=5 and 6, respectively), hepatic and lymphatic metastases (n=4 and 2, respectively) were detected. All five lesions in four patients who underwent PET/CT showed intense FDG uptake on PET/CT with SUVmax (16, range 10.9-21.1). Increase of FDG uptake (SUVmax = 18.9, 20.1, and 27.3, respectively) was revealed on the delayed scan of three lesions in two patients.Conclusions: PSCs were more commonly ill-defined solid cystic masses, which caused pancreatic duct obstruction/compression without pancreatic parenchymal atrophy, and these masses on PET/CT showed high FDG uptake on both initial and delayed PET/CT. [ABSTRACT FROM AUTHOR]