Search

Gamma Delta (γδ) T-cell lymphomas are uncommon and aggressive neoplasms originating from the γδ receptor-bearing lymphocytes. The most frequent entities include primary hepatosplenic γδ T-cell lymphomas, primary cutaneous γδ lymphoma, and monomorphic epitheliotropic T-cell lymphoma. F-18 fluorodeoxyglucose (FDG) PET/CT is an important modality in the staging of Hodgkin's and various non-Hodgkin's lymphoma. However, literature is scare on imaging findings of γδ lymphoma on F-18 FDG PET/CT. In this review, we discuss briefly the clinical and biological features and present the spectrum of F-18 FDG PET/CT findings of γδ lymphoma. [ABSTRACT FROM AUTHOR]

Background MRI alone has limited accuracy for delineating tumor margins and poorly predicts the aggressiveness of gliomas, especially when tumors do not enhance. This study evaluated simultaneous 3,4-dihydroxy-6-[18F]fluoro-L-phenylalanine (FDOPA)-PET/MRI to define tumor volumes compared to MRI alone more accurately, assessed its role in patient management, and correlated PET findings with histopathology. Methods Ten patients with known or suspected gliomas underwent standard of care surgical resection and/or stereotactic biopsy. FDOPA-PET/MRI was performed prior to surgery, allowing for precise co-registration of PET, MR, and biopsies. The biopsy sites were modeled as 5-mm spheres, and the local FDOPA uptake at each site was determined. Correlations were performed between measures of tumor histopathology, and static and dynamic PET values: standardized uptake values (SUVs), tumor to brain ratios, metabolic tumor volumes, and tracer kinetics at volumes of interest (VOIs) and biopsy sites. Results Tumor FDOPA-PET uptake was visualized in 8 patients. In 2 patients, tracer uptake was similar to normal brain reference with no histological findings of malignancy. Eight biopsy sites confirmed for glioma had FDOPA uptake without T1 contrast enhancement. The PET parameters were highly correlated only with the cell proliferation marker, Ki-67 (SUVmax: r = 0.985, P  = .002). In this study, no statistically significant difference between high-grade and low-grade tumors was demonstrated. The dynamic PET analysis of VOIs and biopsy sites showed decreasing time-activity curves patterns. FDOPA-PET imaging directly influenced patient management. Conclusions Simultaneous FDOPA-PET/MRI allowed for more accurate visualization and delineation of gliomas, enabling more appropriate patient management and simplified validation of PET findings with histopathology. [ABSTRACT FROM AUTHOR]

The article discusses a study focusing on the role of silent cerebral infarcts (SCI) in causing morbidity in children with sickle cell anaemia (SCA). Topics discussed include intracranial vasculopathy and infarct recurrence in children with SCA; the magnetic resonance angiography (MRA) performed on the children under study; and the increased risk of SCI in children with intracranial vasculopathy.

OBJECTIVE. The purpose of this article is to summarize the role of molecular imaging of the brain by use of SPECT, FDG PET, and non-FDG PET radiotracers in epilepsy. CONCLUSION. Quantitative image analysis with PET and SPECT has increased the diagnostic utility of these modalities in localizing epileptogenic onset zones. A multi-modal platform approach integrating the functional imaging of PET and SPECT with the morphologic information from MRI in presurgical evaluation of epilepsy can greatly improve outcomes.

Background: MRI alone has limited accuracy for delineating tumor margins and poorly predicts the aggressiveness of gliomas, especially when tumors do not enhance. This study evaluated simultaneous 3,4-dihydroxy-6-[18F]fluoro-L-phenylalanine (FDOPA)-PET/MRI to define tumor volumes compared to MRI alone more accurately, assessed its role in patient management, and correlated PET findings with histopathology., Methods: Ten patients with known or suspected gliomas underwent standard of care surgical resection and/or stereotactic biopsy. FDOPA-PET/MRI was performed prior to surgery, allowing for precise co-registration of PET, MR, and biopsies. The biopsy sites were modeled as 5-mm spheres, and the local FDOPA uptake at each site was determined. Correlations were performed between measures of tumor histopathology, and static and dynamic PET values: standardized uptake values (SUVs), tumor to brain ratios, metabolic tumor volumes, and tracer kinetics at volumes of interest (VOIs) and biopsy sites., Results: Tumor FDOPA-PET uptake was visualized in 8 patients. In 2 patients, tracer uptake was similar to normal brain reference with no histological findings of malignancy. Eight biopsy sites confirmed for glioma had FDOPA uptake without T1 contrast enhancement. The PET parameters were highly correlated only with the cell proliferation marker, Ki-67 (SUV max : r = 0.985, P  = .002). In this study, no statistically significant difference between high-grade and low-grade tumors was demonstrated. The dynamic PET analysis of VOIs and biopsy sites showed decreasing time-activity curves patterns. FDOPA-PET imaging directly influenced patient management., Conclusions: Simultaneous FDOPA-PET/MRI allowed for more accurate visualization and delineation of gliomas, enabling more appropriate patient management and simplified validation of PET findings with histopathology., (© The Author(s) 2020. Published by Oxford University Press on behalf of the Society for Neuro-Oncology and the European Association of Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Objective: To determine whether specific patterns of [ 18 F]-AV-1451 tau-PET retention are observed in patients with autopsy-proven sporadic Creutzfeldt-Jakob disease (CJD)., Methods: In vivo [ 18 F]-AV-1451 PET neuroimaging was performed in 5 patients with sporadic CJD (median age, 66 years [63-74]), and results were compared to cognitively normal (CN) persons (n = 44; median age, 68 years [63-74]) and to participants with very mild Alzheimer disease (AD) dementia (n = 8; median age, 77 years [63-90]). Autopsy was completed in all patients with CJD, confirming the clinical diagnosis and permitting characterization of AD neuropathologic change (ADNC)., Results: All patients with CJD presented with rapidly progressive dementia, typical magnetic resonance brain imaging changes, and elevated CSF total tau (median = 6,519; range = 1,528-13,240 pg/mL). Death occurred within 9 months of symptom onset, with a median 1 month (0.2-3.3) interval from [ 18 F]-AV-1451 PET to autopsy. No unique pattern of [ 18 F]-AV-1451 retention was observed on visual inspection. Summary standardized uptake value ratios in patients with CJD (1.17, 1.08-1.36) were indistinguishable from CN persons (1.14, 0.84-1.54; p = 0.6), and well below those of participants with AD (2.23, 1.60-3.04; p ≤ 0.01). [ 18 F]-AV-1451 retention in patients with CJD and CN persons was similar in brain areas frequently affected in AD and CJD. Neuropathologic analysis confirmed the clinical diagnosis in all patients with CJD. Four patients with CJD also had low-level ADNC (A1B1C0); one patient had intermediate-level ADNC (A2B2C1/2)., Conclusion: Increased [ 18 F]-AV-1451 retention was not observed in patients with rapidly progressive dementia due to sporadic CJD. The [ 18 F]-AV-1451 PET tracer maintains good specificity for paired helical tau filaments associated with AD dementia., (© 2018 American Academy of Neurology.)