Brain 18 F-Florbetapir PET/CT Findings in an Early-onset Alzheimer Disease Patient Carrying Presenilin-1 G378E Mutation.

Positron emission tomography (PET) with 18 F-Fluorodeoxyglucose ( 18 F-FDG) plays an outstanding role in the diagnostic work-up of dementia. Amyloid PET imaging is a complementary imaging technique for the early detection of Alzheimer disease (AD). ß-amyloid precursor protein ( APP ), Presenilin-1 ( PSEN1 ) and Presenilin-2 ( PSEN2 ) are the 3 main causative genes responsible for autosomal dominant early-onset Alzheimer disease (EOAD). This is the first report of 18 F-Florbetapir amyloid imaging findings in a 35-year-old male patient with EOAD carrying the G378E mutation in PSEN1 gene. Brain computed tomography (CT) and magnetic resonance imaging scans showed remarkable cerebral atrophy with dilatation of the cerebrospinal fluid spaces; furthermore, a 18 F-Florbetapir PET/CT scan demonstrated also widespread remarkable accumulation of the amyloid tracer in the cerebral cortex, with reduction of the normal contrast between white and gray matter and flattening of the external cortical margins. Furthermore, PET/CT showed intense 18 F-florbetapir uptake in the striatum and in the thalamus bilaterally. Our case supports the usefulness of amyloid PET imaging in the diagnostic work-up of EOAD.

Italian Multicenter Study on Accuracy of 18F-FDG PET/CT in Assessing Bone Marrow Involvement in Pediatric Hodgkin Lymphoma.

INTRODUCTION: The present study investigated the utility of fluorine-18 (18F) fluoro-2-deoxy-d-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in assessing bone marrow involvement (BMI) compared with bone marrow biopsy (BMB) in newly diagnosed pediatric Hodgkin lymphoma (HL). PATIENTS AND METHODS: A total of 224 pediatric patients with HL underwent 18F-FDG PET/CT at staging. BMB or follow-up imaging was used as the standard of reference for the evaluation of BMI. RESULTS: 18F-FDG PET/CT was negative for BMI in 193 cases. Of the 193 patients, the findings for 16 were originally reported as doubtful and later interpreted as negative for BMI, with negative findings on follow-up imaging and BMB. At BMB, 1 of the 16 patients (6.25%) had BMI. Of the 193 patients, 192 (99.48%) had negative BMB findings. Thus, the 18F-FDG PET/CT findings were truly negative for 192 patients and falsely negative for 1 patient for BMI. CONCLUSION: 18F-FDG PET/CT showed high diagnostic performance in the evaluation of BMI in pediatric HL. Thus, BMB should be ideally reserved for patients presenting with doubtful 18F-FDG PET/CT findings for BMI.

Radiotracers for Amyloid Imaging in Neurodegenerative Disease: State-of-the-Art and Novel Concepts.

The pathological accumulation of different peptides is the common base of many neurodegenerative processes, such as Alzheimer's disease (AD). AD is characterized by amyloid deposits which may cause alterations in neurotransmission, activation of inflammatory mechanisms, neuronal death and cerebral atrophy. Diagnosis in vivo is challenging as the criteria rely mainly on clinical manifestations, which become evident only in a late stage of the disease. While AD can currently be definitively confirmed by postmortem histopathologic examination, in vivo imaging may improve the clinician's ability to identify AD at the earliest stage. In this regard, the detection of cerebral amyloid plaques with positron emission tomography (PET) is likely to improve diagnosis and allow for a prompt start of an effective therapy. Many PET imaging probes for AD-specific pathological modifications have been developed and proved effective in detecting amyloid deposits in vivo. We here review the current knowledge on PET imaging in the detection of amyloid deposits and their application in the diagnosis of AD.