Search

Background: Positron emission tomography（PET） is the standard method for metabolic and quantitative evaluation of therapeutic response to chemotherapy in solid tumors. This study determined the ability of PET parameters used in combination in predicting recurrence-free survival（RFS）after neoadjuvant chemotherapy （NAC）and operation for esophageal cancer. Methods: This single-center retrospective study included 96 patients who underwent 18F-fluorodeoxyglucose-PET/computed tomography before and after NAC. Maximum standardised uptake value（SUVmax）after NAC and the rate of change in SUVmax following NAC（ΔSUVmax）were determined to examine their relationship with postoperative recurrence and clinicopathological factors. Results: Receiver operating characteristic curves, with recurrence after NAC as the event, were used to determine optimal cut-off SUVmax and ΔSUVmax of 6.8 and 45.7, respectively. Using these cut-off values, the patients were classified into four groups: Group A, SUVmax > 6.8 and ΔSUVmax ≤ 45.7; Group B, SUVmax > 6.8 and ΔSUVmax > 45.7; Group C, SUVmax ≤ 6.8 and ΔSUVmax ≤ 45.7; and Group D, SUVmax ≤ 6.8 and ΔSUVmax > 45.7. Of the four groups, Group D had the longest RFS compared to the other groups. Conclusion: Combination of SUVmax with ΔSUVmax was useful for evaluating the effects of NAC in patients with esophageal cancer.

Objective: To explore the value of 18F-fluorodeoxyglucose positron emission tomography–computed tomography (18F-FDG PET/CT) metabolic parameters before and after neoadjuvant chemotherapy in predict...

OBJECTIVE This study aimed to determine whether texture parameters could be used in differentiation between the tumor and the peritumoral tissues based on hybrid 18F-Fluorodeoxyglucose positron emission tomography/computed tomography imaging for patients with rectal cancer. METHODS Seven parameters, including heterogeneity, entropy, energy, skewness, kurtosis, standard deviation, and average brightness, were extracted from positron emission tomography/computed tomography scans of 22 patients (12 male and 10 female; mean age, 61 ± 2 years). RESULTS The peritumoral tissue had a significantly lower value of the heterogeneity parameter (23%) than the tumor. Tumor size (r = -0.48, P < 0.05) and extramural venous invasion scores (r = 0.64, P < 0.05) correlated with heterogeneity in the peritumoral tissue. There were significant differences (P < 0.05) in the correlation coefficients between men and women. CONCLUSIONS Therefore, we provided additional quantitative information to differentiate the tumor from the peritumoral tissue and indicated possible application for extramural venous invasion evaluation in rectal cancer.

Background: Recurrent complex visual hallucinations (VHs) are common in dementia with Lewy bodies (DLB). Previous investigations suggest that VHs are associated with connectivity changes within and...

Background Infective endocarditis (IE) in patients with adult congenital heart disease (ACHD) remains a diagnostic challenge due to difficulties in detecting endocardial lesions by echocardiography. 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) has shown good diagnostic performance in prosthetic valve IE. This study aimed to assess its additional diagnostic value in ACHD-associated IE and to characterize its advantages.Methods and Results:Overall, 22 patients with ACHD and clinical suspicion of IE were retrospectively studied. 18F-FDG PET/CT was performed in addition to conventional assessment based on the modified Duke criteria. The final IE diagnosis was determined by an expert team during a 3-month clinical course, resulting in 18 patients diagnosed with IE. Seven patients (39%) were diagnosed with definite IE only by initial echocardiography. An 18F-FDG PET/CT assessment revealed endocardial involvement in the other 9 patients, resulting in the diagnosis of definite IE in 16 in total (88%). Right-sided endocardial lesions were more common (n=12, 67%) but rarely identified by echocardiography, whereas 18F-FDG PET/CT revealed right-sided lesions in 9 patients. A negative 18F-FDG PET/CT (n=7, 39%) assessment was associated with a native valve IE (71% vs. 0%). In 4 patients who were identified with not-IE, neither echocardiography nor 18F-FDG PET/CT detected any suspicious cardiac involvement. Conclusions In the diagnosis of ACHD-associated IE, characterized by right-sided IE, 18F-FDG PET/CT assessment should be useful.

Introduction: We assessed the influence of education as a proxy of cognitive reserve and age on the dementia with Lewy bodies (DLB) metabolic pattern. Methods: Brain 18F-fluorodeoxyglucose positron emission tomography and clinical/demographic information were available in 169 probable DLB patients included in the European DLB-consortium database. Principal component analysis identified brain regions relevant to local data variance. A linear regression model was applied to generate age- and education-sensitive maps corrected for Mini-Mental State Examination score, sex (and either education or age). Results: Age negatively covaried with metabolism in bilateral middle and superior frontal cortex, anterior and posterior cingulate, reducing the expression of the DLB-typical cingulate island sign (CIS). Education negatively covaried with metabolism in the left inferior parietal cortex and precuneus (making the CIS more prominent). Discussion: These findings point out the importance of tailoring interpretation of DLB biomarkers considering the concomitant effect of individual, non-disease-related variables such as age and cognitive reserve.

BACKGROUND Primary hepatic neuroendocrine tumors (PHNETs) are rare hepatic tumors. Their diagnosis, which is based on radiological findings, is difficult. CASE SUMMARY We present a case of PHNET in a 79-year-old man with no clinical symptoms. Computed tomography (CT) and 2-Deoxy-2-[fluorine-18] fluorodeoxyglucose positron emission tomography/CT (18F-FDG PET/CT) were performed for further evaluation. A hypoattenuating mass with rim-like enhancement in segment 6 of the liver was detected on contrast-enhanced CT imaging. Increased uptake was also observed on 18F-FDG PET/CT. Histopathological and immunohistochemical examinations, which revealed a grade 2 neuroendocrine tumor (NET), confirmed the diagnosis. CONCLUSION Diagnosing PHNET is challenging, and must be distinguished from other liver tumors. Metastatic NETs should be excluded.

International audience; Introduction: Approximately 40% of dementia cases could be delayed or prevented acting on modifiable risk factors including hypertension. However, the mechanisms underlying the hypertension-dementia association are still poorly understood.Methods: We conducted a cross-sectional analysis in 2048 patients from the MEMENTO cohort, a French multicenter clinic-based study of outpatients with either isolated cognitive complaints or mild cognitive impairment. Exposure to hypertension was defined as a combination of high blood pressure (BP) status and antihypertensive treatment intake. Pathway associations were examined through structural equation modeling integrating extensive collection of neuroimaging biomarkers and clinical data.Results: Participants treated with high BP had significantly lower cognition compared to the others. This association was mediated by higher neurodegeneration and higher white matter hyperintensities load but not by Alzheimer's disease (AD) biomarkers.Discussion: These results highlight the importance of controlling hypertension for prevention of cognitive decline and offer new insights on mechanisms underlying the hypertension-dementia association.Highlights: Paths of hypertension-cognition association were assessed by structural equation models. The hypertension-cognition association is not mediated by Alzheimer's disease biomarkers. The hypertension-cognition association is mediated by neurodegeneration and leukoaraiosis. Lower cognition was limited to participants treated with uncontrolled blood pressure. Blood pressure control could contribute to promote healthier brain aging.

Background This study evaluated the prognostic value of preoperative immunoinflammatory scores and 18F-fluorodeoxyglucose positron-emission tomography (FDG-PET) for patients undergoing salvage esophagectomy to identify suitable candidates for surgery. Patients and methods Twenty-five patients undergoing salvage esophagectomy were included. The prognostic value of the preoperative C-reactive protein-to-albumin ratio (CAR), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and maximum standardized FDG uptake value (SUVmax) were investigated. Results Multivariate analysis demonstrated high CAR to be an independent prognostic factor for overall survival (p=0.013). CAR had no association with clinicopathological variables, whereas the SUVmax was significantly positively associated with tumor aggressiveness. Multivariate analysis using residual tumor and the combination of CAR and SUVmax revealed both residual tumor (p=0.009) and high CAR/high SUVmax (p=0.016) to be independent prognostic factors for overall survival. Conclusion Preoperative evaluation of CAR as an immunoinflammatory indicator and SUVmax as a marker of tumor aggressiveness will be useful to identify suitable candidates for this high-risk surgery.

A patient of differentiated follicular thyroid carcinoma with unusual sites of metastases is illustrated with 131I and 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) imaging findings. The described case harbored extremely rare metastasis to the urinary bladder with multi-organ metastatic disease (including unusual sites of right bronchus and hepatic metastases). There was inter-lesional heterogeneity among the metastatic lesions with regard to the 131I and FDG uptake in the aforementioned lesions. The detection of such heterogeneity has important implications for patient management in metastatic differentiated thyroid carcinoma.

Objective To demonstrate the utility of deep learning enhancement (DLE) to achieve diagnostic quality low-dose positron emission tomography (PET)/magnetic resonance (MR) imaging. Methods Twenty subjects with known Crohn disease underwent simultaneous PET/MR imaging after intravenous administration of approximately 185 MBq of 18F-fluorodeoxyglucose (FDG). Five image sets were generated: (1) standard-of-care (reference), (2) low-dose (ie, using 20% of PET counts), (3) DLE-enhanced low-dose using PET data as input, (4) DLE-enhanced low-dose using PET and MR data as input, and (5) DLE-enhanced using no PET data input. Image sets were evaluated by both quantitative metrics and qualitatively by expert readers. Results Although low-dose images (series 2) and images with no PET data input (series 5) were nondiagnostic, DLE of the low-dose images (series 3 and 4) achieved diagnostic quality images that scored more favorably than reference (series 1), both qualitatively and quantitatively. Conclusions Deep learning enhancement has the potential to enable a 90% reduction of radiotracer while achieving diagnostic quality images.

Lesions of the deep digital flexor tendon (DDFT) are a cause for foot lameness in horses. Positron emission tomography (PET) could provide valuable information regarding the metabolic activity of these lesions. The aims of this exploratory, prospective, methods comparison study were to assess the ability of 18 fluorine-fluorodeoxyglucose (18 F-FDG) PET to detect DDFT lesions and to compare the PET findings with CT and MRI findings. Eight horses with lameness due to pain localized to the front feet were included. Both front limbs of all horses were imaged with 18 F-FDG PET, noncontrast CT, and arterial contrast-enhanced CT; 11 limbs were also assessed using MRI. Two observers graded independently 18 F-FDG PET, noncontrast CT, arterial contrast CT, T1-weighted (T1-w) MRI, and T2-weighted (T2-w)/STIR MRI. Maximal standardized uptake values were measured. Lesions were found in seven of 16 DDFT on PET, 12 of 16 DDFT on noncontrast CT, six of 15 DDFT on arterial contrast CT, eight of 11 DDFT on T1-w MRI, and six of 11 DDFT on T2-w/STIR MRI. Positron emission tomography was in better agreement with arterial contrast CT (Kappa-weighted 0.40) and T2-w/STIR MRI (0.35) than with noncontrast CT (0.28) and T1-w MRI (0.20). Maximal standardized uptake values of lesions ranged from 1.9 to 4.6 with a median of 3.1. Chronic lesions with scar tissues identified on noncontrast CT or T1-w MRI did not have increased 18 F-FDG uptake. These results demonstrated that 18 F-FDG PET agreed more closely with modalities previously used to detect active tendon lesions, i.e. arterial contrast CT and T2-w/STIR MRI. 18 Fluorine-fluorodeoxyglucose PET can be used to identify metabolically active DDFT lesions in horses.

Background: Aim of this study was to investigate the relationship between thyroglobulin doubling time (TgDT) and basal risk factors and metabolic parameters derived from 18F-fluorodeoxyglucose (FDG...

Prosthetic valve endocarditis (PVE) is a sinister complication, with high morbidity and mortality. Diagnosis is conventionally based on modified Duke Criteria. 18F-Fluorodeoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET-CT) has shown high accuracy in diagnosing PVE. Positive 18F-FDG uptake in prosthetic valves on PET-CT is now considered major criteria for diagnosis of PVE. We share our experience of 18F-FDG PET-CT imaging as a problem solving tool in a case of suspected PVE and review the relevant literature.

Tuberculosis (TB) is a common bacterial infection in developing countries. Solid-organ and hematopoietic stem cell transplant recipients are more prone to this infection. Reactivation from previously acquired infection is the most common mode. It has to be ruled out in cases of pyrexia of unknown origin (PUO) before ruling out the other possibilities. We present two cases of incidentally detected TB in the posttransplant patients referred for the evaluation of PUO.

Background Giant paraspinal thoracic schwannomas (GPTSs) are benign, slow-growing, encapsulated lesions. They can be intracanalicular, span more than 2 vertebral bodies, and/or have a foraminal component with extraspinal extension >2.5 cm. They pose surgical challenges because of the often unfamiliar complex regional anatomy. We report the largest series of GPTSs and discuss regional surgical strategies for tumors in the thoracic spine. Methods We conducted a retrospective review of GPTSs operated at a national spinal referral center between December 2008 and October 2019. Inclusion criteria included World Health Organization grade 1 GPTS. Patient demographics, clinical features, radiology, and histopathology were assessed. Results Seventeen patients (12 females, 5 males) had a mean age of 48.1 years (range 21–65 years). Five GPTS (29%) were located at T1-T3, 6 (35%) at T4-6, and 6 (35%) below T6. The mean maximum diameter was 58.5 ± 19.1 mm (range 30–91 mm). Mean volume was 90.9 cm3 (range 19.1–350.6 cm3). Twelve (70%) had a fluorodeoxyglucose positron emission tomography scan showing low (25%) or moderate to high (75%) uptake. Six patients (35%) had preoperative computed tomography−guided biopsy. Surgical approaches included 1) manubriotomy and variations (4/17); 2) high lateral thoracotomy (4/17); 3) posterior parascapular (1/17); 4) standard lateral thoracotomy (3/16); 5) posterior/posterolateral (2/17); and 6) combined posterior and thoracotomy (3/17). All patients had gross total resection and were grade 1 cellular schwannomas. No recurrence at final follow-up (mean 36.1 months, range 8–130 months). Conclusions A number of approaches are available to resect GPST in specific locations in the thoracic spine. Total resection is achievable despite complex regional anatomy, location, and tumor extension but often requires anterior or combined approaches.

A 53-year-old woman was admitted to our hospital for headache secondary to an acute subdural haematoma in the right cerebellar tentorium. She had been diagnosed with systemic lupus erythematosus (S...

Infections involving the heart are becoming increasingly common, and a timely diagnosis of utmost importance, despite its challenges. F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is a recently introduced diagnostic tool in cardiology. This review focuses on the current evidence for the use of FDG PET/CT in the diagnosis of infective endocarditis, cardiac implantable device infection, left ventricular assist device infection, and secondary complications. The author discusses considerations when using FDG PET/CT in routine clinical practice, patient preparation for reducing physiologic myocardial uptake, acquisition of images, and interpretation of PET/CT findings. This review also functions to highlight the need for a standardized acquisition protocol.

The appropriate identification and localization of a nidus of a high flow arteriovenous malformation is crucial to guide targeted interventional therapy. However, the nidus of a complex or previously treated HFAVM can be difficult to non–invasively demonstrate on magnetic resonance imaging alone. We describe a unique case of a 56-year-old female with a complex high flow arteriovenous malformation in which we demonstrated the feasibility of fluorodeoxyglucose positron emission tomography/computed tomography to non–invasively delineate the nidus which subsequently guided successful targeted interventional therapy.

The purpose of this study was to generate the PET images with high signal-to-noise ratio (SNR) acquired for typical scan durations (H-PET) from short scan time PET images with low SNR (L-PET) using deep learning and to evaluate the effect of scan time on the quality of predicted PET image. A convolutional neural network (CNN) with a concatenated connection and residual learning framework was implemented. PET data from 27 patients were acquired for 900 s, starting 60 minutes after the intravenous administration of FDG using a commercial PET/CT scanner. To investigate the effect of scan time on the quality of the predicted H-PETs, 10 s, 30 s, 60 s, and 120 s PET data were generated by sorting the 900 s LMF data into the LMF data acquired for each scan time. Twenty-three of the 27 patient images were used for training of the proposed CNN and the remaining four patient images were used for test of the CNN. The predicted H-PETs generated by the CNN were compared to ground-truth H-PETs, L-PETs, and filtered L-PETs processed with four commonly used denoising algorithms. The peak signal-to-noise ratios (PSNRs), normalized root mean square errors (NRMSEs), and average regionof- interest (ROI) differences as a function of scan time were calculated. The quality of the predicted H-PETs generated by the CNN was superior to that of the L-PETs and filtered L-PETs. Lower NRMSEs and higher PSNRs were also obtained from predicted H-PETs compared to the L-PETs and filtered L-PETs. ROI differences in the predicted H-PETs were smaller than those of the L-PETs. The quality of the predicted H-PETs gradually improved with increasing scan times. The lowest NRMSEs, highest PSNRs, and smallest ROI differences were obtained using the predicted H-PETs for 120 s. Various performance test results for the proposed CNN indicate that it is possible to generate H-PETs from neuro FDG L-PETs using the proposed CNN method, which might allow reductions in both scan time and injection dose.

We present the case of a patient with a graft-duodenal fistula after renovisceral debranching thoracic endovascular aortic repair. 18F-fluorodeoxyglucose positron emission tomography with computed tomography showed that the infection was localized to the renovisceral bypass grafts and the right kidney. Based on the preoperative imaging findings, a limited surgery with resection was performed in the fistula, right kidney, and fluorodeoxyglucose-positive bypass grafts, while preserving the fluorodeoxyglucose-negative grafts. No signs of reinfection were reported 2 years after the surgery. Accurate assessment of infection with 18F-fluorodeoxyglucose positron emission tomography with computed tomography may be useful for performing adequate excision of infected lesions.

Background This study was aimed to examine the significance of fluorodeoxyglucose positron emission tomography in predicting prognosis after segmentectomy in lung cancer. Methods This was a retrospective cohort study, including 227 patients with cT1N0M0 nonsmall cell lung cancer who underwent positron emission tomography followed by segmentectomy between 2012 and 2019. Significance of tumor histology, T-stage, tumor size, and standardized uptake value on positron emission tomography in relation to recurrence-free survival were examined using Cox's proportional hazard analysis. Median follow-up period was 56 months (range: 1–95 months). Results Tumor stages were Tis in 25 patients, T1mi/T1a in 51, T1b in 98, and T1c in 53. Twenty-six patients (11%) experienced recurrences, including local (n = 8) and distant (n = 18). Multivariate analysis showed that the significant variables for recurrence-free survival were T-stage and standardized uptake value (p = 0.002 and 0.015, respectively), whereas tumor histology and tumor size were not significant (p = 0.28 and 0.44, respectively). When tumor size was divided into ≤2 cm and >2 cm for analysis, it was not significant again (p = 0.49), whereas standardized uptake value remained significant (p = 0.008). While standardized uptake value of tumors with recurrences was significantly higher than those without (4.9–2.8 and 2.6–2.5, respectively, p Conclusion Positron emission tomography could predict the prognosis after segmentectomy better than tumor size.

OBJECTIVESOur goal was to define characteristic patterns of 18F-fluorodeoxyglucose in non-infected patients with ascending aortic prosthetic grafts during the first year after surgery.METHODS18F-fluorodeoxyglucose positron emission tomography (PET)/computed tomography (CT) was performed at 3, 6 and 12 months postoperatively in 26 uninfected patients. Clinical, analytical and microbiological (blood culture) assessments were performed to confirm the absence of infection. FDG uptake intensity [measured through maximum standardized uptake values (SUVmax) and the target-to-background ratio] and distribution patterns were obtained. Models of generalized estimating equations were used to assess the evolution of the SUVmax over time. The results were compared to those in our endocarditis-over-ascending-aortic-graft series database. The receiver operating characteristic curves of the control group and the 12-month group were assessed.RESULTSAll patients showed increased uptake in all areas. The uptake pattern was heterogeneous in 47.4%, 43.5% and 42.3% at 3, 6 and 12 months. The means and standard deviations of the SUVmax in the graft were 4.80 (±0.99), 4.28 (±0.88) and 4.14 (±0.87) at 3, 6 and 12 months after surgery. A comparison of all values obtained in the 6th and 12th months compared to those from the 3rd month revealed a slow decrease that may persist after the first year. The cut-off value of SUVmax of 4.24 had an overall sensitivity of 84.6% and specificity of 57.7% for patients seen at 12 months.CONCLUSIONSNon-infected ascending aortic grafts showed no predominant uptake pattern; they also showed increased 18F-fluorodeoxyglucose activity that could persist beyond the first year. Caution is therefore recommended when interpreting PET/CT images obtained during the first year after surgery.

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

We describe a rare case of osteogenic sarcoma of the right femur; who 2 years after the treatment of primary site developed dural metastasis. Surveillance imaging for unusual pattern of metastasis may lead to earlier detection and treatment decision-making, which may improve survival and quality of life.

The bone cannot be evaluated using magnetic resonance attenuation correction (MRAC) with the Dixon sequence. To solve this issue, the present study aimed to evaluate model-based AC for whole-body 2-[fluorine-18]-fluoro-2-deoxy-d-glucose (18F-FDG) positron emission tomography (PET)/magnetic resonance imaging (MRI) by creating bone segmentation. We analyzed and evaluated the data of 31 consecutive patients. The Biograph mMR (Siemens Healthcare) was used for clinical whole-body 18F-FDG PET/MRI with the conventional MRAC method, and OSIRIX MD software was used to analyze the images. After the examination, the new model-based post-processing MRAC was applied to create μ-maps with bone segmentation, and retrospective PET reconstruction was performed using this μ-map. The bone structures of all patients created using model-based MRAC were visually evaluated. Standard uptake values (SUVs) at 11 anatomical positions in PET images, corrected using the μ-map with and without bone segmentation, were measured and compared. The model-based post-processing MRAC was run for all patients, without errors. Visual evaluation revealed that the model-based post-processing MRAC exhibited poor results for six patients. Furthermore, it exhibited an increasing trend of SUV in the brain compared to the conventional method. Locations other than the brain indicated a similar or decreasing trend. The two methods showed a good linear correlation for all patients. However, patients aged

Background: Brown adipose tissue (BAT) has an essential role in regulating energy, metabolism, and thermogenesis in mammals. BAT activation is often detected in winter, especially in the female gender and in individuals with normal body mass index (BMI) by 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) modality. It has been reported to be associated with some factors such as age, plasma glucose, and outdoor temperature. Therefore, in this study, we aimed to investigate the characteristics of demographic, metabolic, and other variables of patients with FDG uptake in activated BAT on 18F-FDG PET/CT imaging in patients diagnosed with various types of cancer. Methods: 15752 patients diagnosed with various types of cancer who underwent whole-body 18F-FDG PET/CT imaging for routine diagnosis, staging, or follow-up between March 2017 and April 2019 were screened, and a total of 188 BAT-positive patients were included in this retrospective study. In addition to demographic patient characteristics such as age, height, and weight, data were collected such as BMI, date of birth, date and season of PET/CT imaging, laboratory findings, injection, and PET/CT imaging time, and the average outdoor temperature on the day of PET imaging and evaluated statistically. Results: A total of 188 BAT-positive patients (142 females [75.5%] and 46 males [24.5%]) were included in this study. The mean age of the patient group was 43.89 ± 13.67 years, and the mean BMI was 24.12 ± 3.56. About 103 patients (54.7%) with positive BAT were at normal weight (BMI 18.5–24.9), 49 patients (26.2%) were overweight (BMI 25–30), and 36 patients (19.1%) were obese (BMI >30). The injection time was 76.6% in the afternoon hours, whereas 77.1% of the imaging was performed in the afternoon hours. The mean fasting blood glucose (FBS) was 106.93 ± 14.28 mg/dl, and 61.7% (n = 116) of the patients were hyperglycemic. However, we found no significant relationship between BAT activation and the date of birth, place of birth, PET imaging season (relative to the northern hemisphere), and outdoor temperature. Conclusions: In our study, while BAT FDG uptake was not increased with cold exposure before PET scan and seasonally, female gender, younger age, and mean low BMI are the significant predictive value of BAT activation. Therefore, we aimed to emphasize that BAT activation should be considered to prevent the masking of the image and prevent false-positive involvement, especially in tumor tissue in risky groups.

Objective: This study sought to determine whether 18 F-fluorodeoxyglucose-positron emission tomography/computed tomography could be applied to a murine model of advanced atherosclerotic plaque vulnerability to detect response to therapeutic intervention and changes in lesion stability. Approach and Results: To analyze plaques susceptible to rupture, we fed ApoE −/− mice a high-fat diet and induced vulnerable lesions by cast placement over the carotid artery. After 9 weeks of treatment with orthogonal therapeutic agents (including lipid-lowering and proefferocytic therapies), we assessed vascular inflammation and several features of plaque vulnerability by 18 F-fluorodeoxyglucose-positron emission tomography/computed tomography and histopathology, respectively. We observed that 18 F-fluorodeoxyglucose-positron emission tomography/computed tomography had the capacity to resolve histopathologically proven changes in plaque stability after treatment. Moreover, mean target-to-background ratios correlated with multiple characteristics of lesion instability, including the corrected vulnerability index. Conclusions: These results suggest that the application of noninvasive 18 F-fluorodeoxyglucose-positron emission tomography/computed tomography to a murine model can allow for the identification of vulnerable atherosclerotic plaques and their response to therapeutic intervention. This approach may prove useful as a drug discovery and prioritization method.

We examined if plasma phosphorylated tau is associated with neurodegeneration in Alzheimer’s disease. We investigated 372 cognitively unimpaired participants, 554 mild cognitive impairment patients, and 141 Alzheimer’s disease dementia patients. Tau phosphorylated at threonine 181, regional cortical thickness (using magnetic resonance imaging) and hypometabolism (using fluorodeoxyglucose positron emission tomography) were measured longitudinally. High plasma tau was associated with hypometabolism and cortical atrophy at baseline and over time, and longitudinally increased tau was associated with accelerated atrophy, but these associations were only observed in Aβ‐positive participants. Plasma phosphorylated tau may identify and track processes linked to neurodegeneration in Alzheimer’s disease.

ObjectiveThis study aimed to compare the characteristics of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in gastric lymphoma (GL) and gastric carcinoma (GC).METHODSPatients with newly diagnosed GL or GC who underwent 18F-FDG PET/CT prior to treatment were included in this study. The PET/CT features of gastric wall lesions, including FDG avidity, pattern, and intensity [maximal standard uptake value (SUVmax)] were reviewed and analyzed. The correlation of SUVmax with gastric clinicopathological variables was investigated by Student’s t test, Mann-Whitney U test, chi-square test, and receiver-operating characteristic (ROC) curve analysis to determine the differential diagnostic value of SUVmax-associated parameters in GL and GC.RESULTSA total of 68 patients with GL and 117 with GC were included in this study. Abnormal gastric FDG accumulation was found in 66 (97.05%) patients with GL and 109 (93.16%) patients with GC. Majority of the GL patients presented with type I and III lesions, whereas GC patients mainly with type II and III lesions. The SUVmax [14.89(6.56，22.12) vs 4.08(5.75，10.24), P

estrogen receptor (ER)+/human epithelial growth factor receptor 2 (HER2)- breast cancers have less aggressive traits and a favorable prognosis when treated early. Prediction of prognosis for treatment outcome or survival in ER+/HER2- cancer is important. Ultrasound (US) is an effective and easy technique for breast cancer diagnosis and tumor characterization. Positron emission tomography/computed tomography (PET/CT) is widely used for diagnosis, staging, and therapeutic response in cancer evaluation, and a high maximum standardized uptake value (SUVmax) is associated with poor prognosis. The study aim was to compare the prognostic value of US features with that of the SUVmax assessed by PET/CT in ER+/HER- breast cancer patients. We retrospectively identified breast cancer patients in our institutional database who had undergone preoperative US and PET/CT, and 96 patients with invasive ductal carcinoma and ductal carcinoma in situ were included in this study. The US features of mass shape, margin, echo pattern, orientation, posterior features, boundary, and calcification in the mass were analyzed. We then analyzed the US features to look for correlations with SUVmax and associations with margins, boundaries, posterior features, histological grade, and ki-67 expression. High SUVmax was correlated with irregular shape, not-circumscribed margin, posterior acoustic enhancement, echogenic halo, and calcification in the mass (P0.05, all). Posterior acoustic enhancement was correlated with high ki-67 expression. Many US features of ER+/HER- breast cancer showed associations with SUVmax. Some US features of ER+/HER- breast cancer were useful for predicting prognosis.

International audience; OBJECTIVES: The aim of this study was to assess the diagnostic performances of (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET)/computed tomography (CT) in congenital heart disease (CHD) patients with pulmonary prosthetic valve or conduit endocarditis (PPVE) suspicion. BACKGROUND: PPVE is a major issue in the growing CHD population. Diagnosis is challenging, and usual imaging tools are not always efficient or validated in this specific population. Particularly, the diagnostic yield of (18)F-FDG PET/CT remains poorly studied in PPVE. METHODS: A retrospective multicenter study was conducted in 8 French tertiary centers. Children and adult CHD patients who underwent (18)F-FDG PET/CT in the setting of PPVE suspicion between January 2010 and May 2020 were included. The cases were initially classified as definite, possible, or rejected PPVE regarding the modified Duke criteria and finally by the Endocarditis Team consensus. The result of (18)F-FDG PET/CT had been compared with final diagnosis consensus used as gold-standard in our study. RESULTS: A total of 66 cases of PPVE suspicion involving 59 patients (median age 23 years, 73% men) were included. Sensitivity, specificity, positive predictive value, and negative predictive value of (18)F-FDG PET/CT in PPVE suspicion were respectively: 79.1% (95% CI: 68.4%-91.4%), 72.7% (95% CI: 60.4%-85.0%), 91.9% (95% CI: 79.6%-100.0%), and 47.1% (95% CI: 34.8%-59.4%). (18)F-FDG PET/CT findings would help to correctly reclassify 57% (4 of 7) of possible PPVE to definite PPVE. CONCLUSIONS: Using (18)F-FDG PET/CT improves the diagnostic accuracy of the Duke criteria in CHD patients with suspected PPVE. Its high positive predictive value could be helpful in routine to shorten diagnosis and treatment delays and improve clinical outcomes.

A 61-year-old male patient with known kidney dysfunction who underwent a non-contrast thorax CT and was then referred to our department for metabolic assessment of solitary pulmonary nodule (SPN). The patient underwent dynamic FDG PET/CT to differentiate benign from malignant SPN. This case illustrates the usefulness of dynamic FDG PET/CT imaging when assessing SPN especially in patients with suspicion for pulmonary arterio-venous malformation accompanying renal failure or contrast allergy.

To determine the accuracy of 18F-Fluorodeoxyglucose positron emission tomography computed tomography (FDG-PET CT) in predicting response to neoadjuvant chemoradiation (NACRT) in esophageal squamous cell cancer (SCC) and impact of such response on survival. Retrospective analysis of patients with esophageal SCC (cT2-4N0-N+M0) who underwent PET CT before and 6 weeks after NACRT followed by surgery was carried out in this study. Metabolic response was assessed by change in standardized uptake value (ΔSUVmax) after NACRT and the pathological response was graded. A receiver operating characteristic curve (ROC) was used to identify the optimal cut off value of SUVmax to predict histopathological response. The impact of metabolic response and pathological response on survival was determined. Of the 73 patients analyzed, 27 had complete metabolic response, while 24 had pathological complete response (PCR). However, only 14 of the 27 complete metabolic responders actually had PCR. At 67% ΔSUVmax, the optimum balance between sensitivity (70.83%) and specificity (69.23%) was achieved and the correlation between metabolic response and pathological complete response achieved statistical significance (p = 0.0009). However, ΔSUVmax of 67% was found to have no significant association with survival (p = 0.51). PCR was the only significant determinant of improved survival (p = 0.04). PCR which is a significant determinant of survival is not ideally predicted by ΔSUVmax on PET CT.

The diagnosis of cardiac sarcoidosis (CS) is challenging. Recently, guidelines incorporated cardiac positron emission tomography (PET) with 18F-Fluorodeoxyglucose (F18-FDG) as a non-invasive diagnostic modality for the detection and follow-up of CS. However, this technique is dependent of patient dietary preparation to suppress physiological myocardial F18-FDG uptake. We present a case of possible CS which highlights a novel preparation protocol that facilitated appropriate myocardial suppression.

Vascular graft infection (VGI) is a rare and severe complication after vascular surgery associated with significant morbidity and mortality, but the diagnosis is not always straightforward due to its variable and nonspecific clinical signs. Computed tomography (CT) scan is considered to be the diagnostic tool of choice for advanced VGI, but there is a high incidence of false-negative results, especially in low-grade infections. 18F-Fluorodeoxyglucose positron emission tomography with contrast-enhanced CT (18F-FDG PET-CT) imaging can serve as an effective alternative tool for assessment of suspected VGI and also provide accurate anatomic localization of the infective focus. Here, we describe three cases of VGI with various clinical presentations where the site of infection was diagnosed, confirmed, and documented with the help of 18F-FDG PET-CT imaging.

Anorectal malignant melanoma (ARM) is a rare variant of malignant melanoma and even more rare among all anorectal cancers. 18F-fluorodeoxyglucose (FDG) positron emission tomography–computed tomography (CT) scan is valuable in staging, restaging, treatment response evaluation, and long-term follow-up of malignant melanoma. Here, reporting two cases of anorectal melanoma with a variety of FDG uptake pattern and CT-based features and reviewed a few articles to evaluate the pattern of FDG uptake.

Tocilizumab (TCZ; Actemra/RoActemra) is an anti-interleukin (IL)-6 receptor antibody for the treatment of rheumatoid arthritis (RA) and other autoimmune diseases and cytokine storms. The present case is a 63-year-old female well-controlled RA patient, who presented with a progressive cognitive impairment after 34 months of TCZ administration. Brain magnetic resonance imaging (MRI) showed leukencephalopathy with a lactic acid peak in magnetic resonance spectroscopy (MRS), a decreased blood flow in single photon emission computed tomography (SPECT), and a decreased accumulation in fluorodeoxyglucose positron emission tomography (FDG-PET). The discontinuation of TCZ improved her cognitive function and brain MRI findings at 3 months after drug cessation. The present case suggests that TCZ may sometimes cause leukoencephalopathy after long-term administration, and thus the early discontinuation of TCZ is recommended to achieve a good prognosis.

Background The purpose of this study is to assess the role of 18 fluorodeoxyglucose positron emission tomography/computed tomography (18FDG PET-CT) in the follow-up of patients with lymphoma after finishing therapy. Results This study included 42 lymphomas (25 non-Hodgkin’s lymphoma and 17 Hodgkin’s lymphoma); patients ranging in age from 18 to 70 years were examined by 18FDG PET-CT after therapy and analyzed retrospectively. Confirmatory biopsy was mandatory in cases of suspected disease recurrence and follow-up in cases of complete metabolic response. Positron emission tomography/computed tomography in assessment of lymphoma treatment response reveals significant statistical significance (P < 0.05). It shows 100% sensitivity, 92.8% specificity, and 95.2% accuracy in the prediction of response. Conclusion Positron emission tomography/computed tomography plays an important role in detection of response to treatment of lymphoma after finishing therapy.

CT were analyzed. The subjects were elderly people aged 55–75 who volunteered for brain 18F of the FDG CT and PET scanning. The elderly who maintained exercise were divided into exercise group and non-exercise group into control group. The images obtained by CT examination showed that the brain of the elderly who insisted on exercise showed a significant increase in glucose metabolism, which indicated that exercise had a preventive effect on brain diseases of the elderly, and reduced the risk of cerebral vascular occlusion and brain atrophy.

This case report presents a patient with recurrent pleomorphic mantle cell lymphoma (MCL), which is a relatively rare but aggressive type of lymphoma. A positron emission tomography/computed tomography scan performed to assess treatment response demonstrated a complete metabolic response in the sites of primary disease while also revealing new subcutaneous lesions, which were biopsy-proven recurrent disease. This case illustrates the importance of the different biological behavior of MCL, whereby new sites of metabolically active lesions can represent recurrent disease, even though there is a complete metabolic response at sites of primary disease.

Whole-body 18F-fluorodeoxyglucose positron emission tomography (PET) has been used extensively in the last decade for the primary staging and restaging and to assess response to therapy in these patients. We aim to discuss the diagnostic performance of PET/computed tomography in the initial staging of breast carcinoma including the locally advanced disease and to illustrate its role in restaging the disease and in the assessment of response to therapy, particularly after the neoadjuvant chemotherapy. Causes of common pitfalls during image interpretations will be also discussed.

New onset refractory status epilepticus (NORSE), is a rare, neurological condition characterised by prolonged periods of refractory epileptic seizure with no readily identifiable cause in otherwise healthy individuals. Anatomical imaging like MRI and serology is usually unremarkable. In patients who have underlying etiology as auto-immune encephalitis without any evidence of auto-antibodies FDG PET may help in early diagnosis and treatment response as it tends to accumulate in the neuronal tissue whenever there is increased blood flow, metabolic demand or increased electrical activity which reverts back with clinical recovery.

Multiple studies have investigated the disruptions in structural and functional connectivity in aging, dementia and Alzheimer’s disease (AD). The study of metabolic connectivity between brain regions using fluorodeoxyglucose positron emission tomography (FDG-PET) however, is a new focus of interest. Several methodological approaches, including seed-based correlation, independent and principal component analysis, and graph-theoretical approaches have been employed to study the metabolic disconnectivity in AD. We conducted a systematic search of the literature using the keywords metabolic connectivity and Alzheimer disease, up to the date of last submission and included 15 original articles as relevant. Existing literature implies a generalized metabolic disconnectivity in the brain which closely follow findings from functional studies. In the following review, we introduce the concept of metabolic disconnectivity and discuss the alterations in metabolic connectivity in AD and the potential underlying mechanisms. We find it imperative for future studies to investigate alterations in metabolic and functional connectome of AD and mild cognitive disorder through simultaneous acquisition of FDD-PET, functional and structural scans.

The aim of this study was to assess the accuracy of 18F-fluorodeoxyglucose positron emission tomography (18-FDG-PET scan) in localizing the disease in differentiated thyroid carcinoma patients undergoing re-operations. This is a retrospective analysis of a prospectively maintained data (December 2007 to December 2016). The patients included had elevated serum thyroglobulin (Tg) levels and negative iodine uptake (TENIS) and planned for re-operation with one or more accessible site of metastasis detected on FDG-PET scan. Clinical details, FDG-PET/CT findings, operative findings, histology, pre-, and post-operative Tg levels were recorded. Thirty-two patients were included. The mean age of the patients was 46.8 ± 15.8 years (M:F = 1:1.6) and mean pre-operative Tg value was 247.6 ± 92.3 ng/ml. FDG-PET disclosed a total of 77 hot spots in these 32 patients, 56 of which were surgically explored and resections performed. Patient- and lesion-based positive predictive value (PPV) of FDG-PET in detecting recurrent/metastatic DTC lesions was 87.5 and 71%, respectively. Remaining cases had granulomatous or nonspecific inflammatory lesions. A total of 12.5% of recurrent DTC patients explored could achieve biochemical cure. All these had disease confined to neck. Remaining patients continued to have high serum Tg level, though it fell substantially in majority of patients. False positive scans are frequent in regions with high prevalence of inflammatory diseases. Hence, FDG-PET directed re-operations should be taken up judiciously.