Toward Semiautomated Analysis of Cerebrovascular Reserve: Enhancing Objective Comparisons Using 99mTc-HMPAO SPECT With Acetazolamide in Moyamoya.

Background And Objectives: Cerebrovascular reserve (CVR) is a key physiological mechanism allowing the brain to adapt to fluctuating perfusion, particularly relevant in the management of neurovascular disorders such as idiopathic (iMM) and syndromic moyamoya (sMM). Although 99mTc-HMPAO SPECT with acetazolamide is commonly used for CVR assessment, it faces limitations including low spatial resolution, artifacts, and variability in interpretation. This study primarily aims to evaluate a novel, semiautomated, and more objective method for interpreting HMPAO SPECT in CVR assessment.

Pure autonomic failure: a natural history study of the Queen Square cohort.

The current research challenge in pure autonomic failure (PAF) lies in identifying specific biomarkers that can differentiate it from the other Lewy body disorders (Parkinson's disease, Parkinson's disease dementia, dementia with Lewy bodies) and multiple system atrophy in the early stages and predict phenoconversion trajectories to more widespread impairment. In this study, we described the natural history of our cohort of PAF patients over five decades and validated a cluster of clinical, autonomic, and neuroimaging biomarkers that help identify clinical profiles susceptible to further neurodegeneration, working towards a biological definition of PAF. Consecutive patients with an initial diagnosis of PAF were recruited and monitored through key milestones (disease onset, first and repeat autonomic assessment, phenoconversion, and death/final contact).

Mild Metabolism Increase on Posttreatment 18F-FDG PET may Indicate Recurrence of Primary CNS Lymphoma.

In immunocompetent patients, primary central nervous system lymphoma (PCNSL) typically presents with homogeneously enhancing brain lesions and high 18F-FDG avidity, ranging from 2 to 5 times higher than that of healthy tissue at baseline. We present the case of a 34-year-old woman in whom PCNSL recurrence was questioned due to the appearance of mildly increased glucose metabolism (1.3 times higher than normal contralateral tissue) and FLAIR hypersignals, despite the absence of contrast enhancement or cerebrospinal fluid abnormalities.

A 3D convolutional neural network to classify subjects as Alzheimer's disease, frontotemporal dementia or healthy controls using brain 18F-FDG PET.

With the arrival of disease-modifying drugs, neurodegenerative diseases will require an accurate diagnosis for optimal treatment. Convolutional neural networks are powerful deep learning techniques that can provide great help to physicians in image analysis. The purpose of this study is to introduce and validate a 3D neural network for classification of Alzheimer's disease (AD), frontotemporal dementia (FTD) or cognitively normal (CN) subjects based on brain glucose metabolism.

Myocardial, Retro-orbital, and Bilateral Testicular Metastases of an Ileal Neuroendocrine Tumor in 68 Ga-DOTATATE PET/CT.

A 71-year-old man with a newly discovered metastatic grade II neuroendocrine tumor of the terminal ileum was referred for a 68 Ga-DOTATATE PET/CT scan to stage the disease and assess suitability for PRRT (peptide receptor radionuclide therapy). The patient was known to have secondary nodal and bone/liver metastatic disease through prior morphological investigations. PET images revealed an atypical pattern of metastatic disease, showcasing secondary lesions in bilateral extraocular muscles, the myocardium, and both testes.

Optimization of Automated Radiosynthesis of Gallium-68-Labeled PSMA11 with Two [Ge]Ge/[Ga]Ga Generators: Fractional Elution or Prepurification?

Prostate cancer is one of the most common forms of cancer in men. An imaging technique for its diagnosis is [Ga]-prostate-specific membrane antigen ([Ga]Ga-PSMA-11) positron emission tomography (PET). To address the increasing demand for [Ga]-labeled peptides and reduce the cost of radiosynthesis, it is therefore necessary to optimize the elution process of [Ge]Ge/[Ga]Ga generators.

The relationship between glutamate, dopamine, and cortical gray matter: A simultaneous PET-MR study.

Prefrontal cortex has been shown to regulate striatal dopaminergic function via glutamatergic mechanisms in preclinical studies. Concurrent disruption of these systems is also often seen in neuropsychiatric disease. The simultaneous measurement of striatal dopamine signaling, cortical gray matter, and glutamate levels is therefore of major interest, but has not been previously reported.