Pragmatic algorithm for visual assessment of 4-Repeat tauopathies in [F]PI-2620 PET Scans.

Aim: Standardized evaluation of [F]PI-2620 tau-PET scans in 4R-tauopathies represents an unmet need in clinical practice. This study aims to investigate the effectiveness of visual evaluation of [F]PI-2620 images for diagnosing 4R-tauopathies and to develop a straight-forward reading algorithm to improve objectivity and data reproducibility.

Methods: A total of 83 individuals with [F]PI-2620 PET scans were included.

Neuronal and oligodendroglial, but not astroglial, tau translates to in vivo tau PET signals in individuals with primary tauopathies.

Tau PET has attracted increasing interest as an imaging biomarker for 4-repeat (4R)-tauopathy progressive supranuclear palsy (PSP). However, the translation of in vitro 4R-tau binding to in vivo tau PET signals is still unclear. Therefore, we performed a translational study using a broad spectrum of advanced methodologies to investigate the sources of [F]PI-2620 tau PET signals in individuals with 4R-tauopathies, including a pilot PET autopsy study in patients.

SNMMI Procedure Standard/EANM Practice Guideline for Brain [F]FDG PET Imaging, Version 2.0.

PREAMBLEThe Society of Nuclear Medicine and Molecular Imaging (SNMMI) is an international scientific and professional organization founded in 1954 to promote the science, technology, and practical application of nuclear medicine. The European Association of Nuclear Medicine (EANM) is a professional nonprofit medical association that facilitates communication worldwide between individuals pursuing clinical and research excellence in nuclear medicine. The EANM was founded in 1985.

Combining cerebrospinal fluid and PI-2620 tau-PET for biomarker-based stratification of Alzheimer's disease and 4R-tauopathies.

Introduction: Recent advances in biomarker research have improved the diagnosis and monitoring of Alzheimer's disease (AD), but in vivo biomarker-based workflows to assess 4R-tauopathy (4RT) patients are currently missing. We suggest a novel biomarker-based algorithm to characterize AD and 4RTs.

Methods: We cross-sectionally assessed combinations of cerebrospinal fluid measures (CSF p-tau and t-tau) and F-PI-2620 tau-positron emission tomography (PET) in patients with AD (n = 64), clinically suspected 4RTs (progressive supranuclear palsy or corticobasal syndrome, n = 82) and healthy controls (n = 19).

Added value of FDG-PET for detection of progressive supranuclear palsy.

Background: Diagnostic criteria for progressive supranuclear palsy (PSP) include midbrain atrophy in MRI and hypometabolism in [F]fluorodeoxyglucose (FDG)-positron emission tomography (PET) as supportive features. Due to limited data regarding their relative and sequential value, there is no recommendation for an algorithm to combine both modalities to increase diagnostic accuracy. This study evaluated the added value of sequential imaging using state-of-the-art methods to analyse the images regarding PSP features.

Towards multicenter β-amyloid PET imaging in mouse models: A triple scanner head-to-head comparison.

Aim: β-amyloid (Aβ) small animal PET facilitates quantification of fibrillar amyloidosis in Alzheimer's disease (AD) mouse models. Thus, the methodology is receiving growing interest as a monitoring tool in preclinical drug trials. In this regard, harmonization of data from different scanners at multiple sites would allow the establishment large collaborative cohorts and may facilitate efficacy comparison of different treatments.

Clinical and diagnostic implications of Alzheimer's disease copathology in Lewy body disease.

Concomitant Alzheimer's disease (AD) pathology is a frequent event in the context of Lewy body disease (LBD), occurring in approximately half of all cases. Evidence shows that LBD patients with AD copathology show an accelerated disease course, a greater risk of cognitive decline and an overall poorer prognosis. However, LBD-AD cases may show heterogeneous motor and non-motor phenotypes with a higher risk of dementia and, consequently, be not rarely misdiagnosed.

Assessment of [F]PI-2620 Tau-PET Quantification via Non-Invasive Automatized Image Derived Input Function.

Purpose: [F]PI-2620 positron emission tomography (PET) detects misfolded tau in progressive supranuclear palsy (PSP) and Alzheimer's disease (AD). We questioned the feasibility and value of absolute [F]PI-2620 PET quantification for assessing tau by regional distribution volumes (V). Here, arterial input functions (AIF) represent the gold standard, but cannot be applied in routine clinical practice, whereas image-derived input functions (IDIF) represent a non-invasive alternative.

Improved Tau PET SUVR Quantification in 4-Repeat Tau Phenotypes with [F]PI-2620.

We used a new data-driven methodology to identify a set of reference regions that enhanced the quantification of the SUV ratio of the second-generation tau tracer 2-(2-([F]fluoro)pyridin-4-yl)-9H-pyrrolo[2,3-b:4,5-c']dipyridine ([F]PI-2620) in a group of patients clinically diagnosed with 4-repeat tauopathy, specifically progressive supranuclear palsy or cortical basal syndrome. The study found that SUV ratios calculated using the identified reference regions (i.e.

EANM practice guidelines for an appropriate use of PET and SPECT for patients with epilepsy.

Epilepsy is one of the most frequent neurological conditions with an estimated prevalence of more than 50 million people worldwide and an annual incidence of two million. Although pharmacotherapy with anti-seizure medication (ASM) is the treatment of choice, ~30% of patients with epilepsy do not respond to ASM and become drug resistant. Focal epilepsy is the most frequent form of epilepsy.

Tau accumulation is associated with dopamine deficiency in vivo in four-repeat tauopathies.

Purpose: We hypothesized that severe tau burden in brain regions involved in direct or indirect pathways of the basal ganglia correlate with more severe striatal dopamine deficiency in four-repeat (4R) tauopathies. Therefore, we correlated [F]PI-2620 tau-positron-emission-tomography (PET) imaging with [I]-Ioflupane single-photon-emission-computed tomography (SPECT) for dopamine transporter (DaT) availability.

Methods: Thirty-eight patients with clinically diagnosed 4R-tauopathies (21 male; 69.

Resting-state alterations in behavioral variant frontotemporal dementia are related to the distribution of monoamine and GABA neurotransmitter systems.

Background: Aside to clinical changes, behavioral variant frontotemporal dementia (bvFTD) is characterized by progressive structural and functional alterations in frontal and temporal regions. We examined if there is a selective vulnerability of specific neurotransmitter systems in bvFTD by evaluating the link between disease-related functional alterations and the spatial distribution of specific neurotransmitter systems and their underlying gene expression levels.

Methods: Maps of fractional amplitude of low-frequency fluctuations (fALFF) were derived as a measure of local activity from resting-state functional magnetic resonance imaging for 52 bvFTD patients (mean age = 61.

Association of Neurofilament Light Chain, [F]PI-2620 Tau-PET, TSPO-PET, and Clinical Progression in Patients With β-Amyloid-Negative CBS.

Background And Objectives: Corticobasal syndrome (CBS) with underlying 4-repeat tauopathy is a progressive neurodegenerative disease characterized by declining cognitive and motor functions. Biomarkers for assessing pathologic brain changes in CBS including tau-PET, 18 kDa translocator protein (TSPO)-PET, structural MRI, neurofilament light chain (NfL), or glial fibrillary acidic protein (GFAP) have recently been evaluated for differential diagnosis and disease staging, yet their association with disease trajectories remains unclear. Therefore, we performed a head-to-head comparison of neuroimaging (tau-PET, TSPO-PET, structural MRI) and plasma biomarkers (NfL, GFAP) as prognostic tools for longitudinal clinical trajectories in β-amyloid (Aβ)-negative CBS.

Theranostics in Neurooncology: Heading Toward New Horizons.

Therapeutic approaches to brain tumors remain a challenge, with considerable limitations regarding delivery of drugs. There has been renewed and increasing interest in translating the popular theranostic approach well known from prostate and neuroendocrine cancer to neurooncology. Although far from perfect, some of these approaches show encouraging preliminary results, such as for meningioma and leptomeningeal spread of certain pediatric brain tumors.

Automatic covariance pattern analysis outperforms visual reading of F-fluorodeoxyglucose-positron emission tomography (FDG-PET) in variant progressive supranuclear palsy.

Background: To date, studies on positron emission tomography (PET) with F-fluorodeoxyglucose (FDG) in progressive supranuclear palsy (PSP) usually included PSP cohorts overrepresenting patients with Richardson's syndrome (PSP-RS).

Objectives: To evaluate FDG-PET in a patient sample representing the broad phenotypic PSP spectrum typically encountered in routine clinical practice.

Methods: This retrospective, multicenter study included 41 PSP patients, 21 (51%) with RS and 20 (49%) with non-RS variants of PSP (vPSP), and 46 age-matched healthy controls.

International Nuclear Medicine Consensus on the Clinical Use of Amyloid Positron Emission Tomography in Alzheimer's Disease.

Alzheimer's disease (AD) is the main cause of dementia, with its diagnosis and management remaining challenging. Amyloid positron emission tomography (PET) has become increasingly important in medical practice for patients with AD. To integrate and update previous guidelines in the field, a task group of experts of several disciplines from multiple countries was assembled, and they revised and approved the content related to the application of amyloid PET in the medical settings of cognitively impaired individuals, focusing on clinical scenarios, patient preparation, administered activities, as well as image acquisition, processing, interpretation and reporting.

Individual regional associations between Aβ-, tau- and neurodegeneration (ATN) with microglial activation in patients with primary and secondary tauopathies.

β-amyloid (Aβ) and tau aggregation as well as neuronal injury and atrophy (ATN) are the major hallmarks of Alzheimer's disease (AD), and biomarkers for these hallmarks have been linked to neuroinflammation. However, the detailed regional associations of these biomarkers with microglial activation in individual patients remain to be elucidated. We investigated a cohort of 55 patients with AD and primary tauopathies and 10 healthy controls that underwent TSPO-, Aβ-, tau-, and perfusion-surrogate-PET, as well as structural MRI.