Brain PET metabolic abnormalities in patients with long-lasting macrophagic myofasciitis

International audienc

Architecture of the fully connected CNN with a 3 layer “U-Net” architecture.

<p>Architecture of the fully connected CNN with a 3 layer “U-Net” architecture.</p

Confusion matrix at the voxel level in the validation set of 11 patients.

<p>Confusion matrix at the voxel level in the validation set of 11 patients.</p

Learning curves with DSC over epochs (upper panel) and loss over epochs (lower panel).

<p>Learning curves with DSC over epochs (upper panel) and loss over epochs (lower panel).</p

Segmentation examples with for each example: Original resized slices ¹⁸F-FET (top), original mask (middle up), predicted mask + threshold (middle down) and difference between the predicted and original mask (bottom, with false negative in red and false positive in blue).

<p>Segmentation examples with for each example: Original resized slices ¹⁸F-FET (top), original mask (middle up), predicted mask + threshold (middle down) and difference between the predicted and original mask (bottom, with false negative in red and false positive in blue).</p

Complementarity of visual and voxel-based FDG-PET analysis to detect MCI-like hypometabolic pattern in elderly patients with hypertension and isolated memory complaints

International audienceBACKGROUND:18F-FDG PET can be used to aid in the diagnosis of Alzheimer's disease (AD) and clarify the diagnosis and prognosis of patients with mild cognitive impairment (MCI).PURPOSE:To compare the results of a quantitative analysis of FDG-PET brain images to a standard visual analysis (SVA) with regards to the detection of MCI-like hypometabolic pattern in elderly patients with hypertension and subjective, isolated memory complaints.MATERIAL AND METHODS:FDG-PET brain was performed in 71 patients (mean age, 76.4 ± 5.1 years; women, 53.5%). Images were analyzed for the presence of an MCI-like hypometabolic pattern using an SVA by 2 physicians and a voxel-based statistical procedure (statistical parametric mapping [SPM]) that compared each patient's images to normal reference samples from 19 elderly individuals obtained using the same PET camera. The reliability of these analyses was evaluated according to neuropsychological assessment results, including the Grober & Buschke Free and Cued Selective Reminding Test, and a combined analysis by a neuropsychologist.RESULTS:An MCI-like hypometabolic pattern was documented in 5 patients (7%) by SVA and 7 patients (10%) by SPM analysis; however, only 2 of these patients were selected by both methods. The group characteristics of the 7 patients identified by the quantitative method were consistent with the MCI pattern, which included a higher rate of abnormal GB-FCSRT in Free Recall (57% vs. 9%, p < 0.05) or in Total Recall (29% vs. 8%, p < 0.05) when compared with other patients. In contrast, the group identified by SVA did not exhibit these characteristics.CONCLUSION:A combined visual and quantitative analysis improves the diagnostic accuracy to detect an MCI-like hypometabolic pattern in elderly patients with hypertension and subjective, isolated memory complaints

Physiological Whole-Brain Distribution of [18F]FDOPA Uptake Index in Relation to Age and Gender: Results from a Voxel-Based Semi-quantitative Analysis

International audiencePurpose6-[18F]fluoro-l-DOPA ([18F]FDOPA), a positron emission tomography (PET) amino-acid tracer of brain decarboxylase activity, is used to assess the brain dopaminergic system. Using a voxel-based semi-quantitative analysis, this study aimed to determine whether a current brain uptake index of [18F]FDOPA, expressed relative to the occipital background level, varies according to age and gender.ProceduresOne hundred and seventy-seven subjects were retrospectively included. A whole-brain statistical parametric mapping analysis of the [18F]FDOPA uptake index in parametric PET images was performed at a voxel threshold of p  125).ResultsStriatal uptake indices were influenced by age, negatively for the caudate nucleus and positively for the putamen, as well as by gender, with a lower left putaminal uptake index in women. Extra-striatal uptake indices were influenced by age, negatively for the frontal cortex and brainstem and positively for the occipital cortex and cerebellum, as well as by gender (diffuse increase in women).ConclusionsThe uptake index of [18F]FDOPA exhibited significant physiological variations according to age and gender and should therefore be considered for PET interpretation

‘Just Because You Teach, Doesn’t Mean It’s Over’:Bunheads and the Pedagogy of Live Performance

International audienc

Predictive value of brain 18F-FDG PET/CT in macrophagic myofasciitis?

International audienceRationale: Although several functional studies have demonstrated that positron emission tomography/computed tomography with 18 F-fluorodeoxyglucose (18 F-FDG PET/CT) appears to be efficient to identify a cerebral substrate in patients with known macrophagic myofasciitis (MMF), the predictive value of this imaging technique for MMF remains unclear. Patient concerns: We presented data and images of a 46-year-old woman. Diagnoses: The patient was referred to our center for suspected MMF due to diffuse arthromyalgias and cognitive disorder (involving an impairment of visual selective attention and a weakness in executive functions revealed by neuropsychological assessment) which occurred few years after last vaccine injections. Interventions: After a first negative deltoid muscle biopsy, a brain 18 F-FDG PET/CT was performed and revealed the known spatial pattern of a cerebral glucose hypometabolism involving occipital cortex, medial temporal areas, and cerebellum. Outcomes: Given the clinical suspicion of MMF and brain 18 F-FDG PET/CT findings, a 2nd deltoid muscle biopsy was performed and confirmed the diagnosis of MMF with typical histopathological features. Lessons: This case highlights the predictive value of brain 18 F-FDG PET/CT as a noninvasive imaging tool for MMF diagnosis, even when muscle biopsy result comes back negative. Abbreviations: 18 F-FDG = 18 F-fluorodeoxyglucose, MMF = macrophagic myofasciitis, PET/CT = positron emission tomography/ computed tomography