Regional Metabolic Abnormalities in Autoimmune Encephalitis: A Meta-analysis of 498 Cases With Brain FDG PET.

Purpose: Autoimmune encephalitis (AIE) is a group of conditions that are insufficiently understood and difficult to diagnose. Several publications indicate that FDG PET has superior sensitivity compared with MRI. This study aimed to perform a systematic review of publications to assess the characteristics and frequency of brain FDG PET compared with MRI findings at the individual level in AIE, including case reports and case series.

An exploratory study of the damage markers NfL, GFAP, and t-Tau, in cerebrospinal fluid and other findings from a patient cohort enriched for suspected autoimmune psychiatric disease.

There is growing evidence suggesting that immunological mechanisms play a significant role in the development of psychiatric symptoms in certain patient subgroups. However, the relationship between clinical red flags for suspected autoimmune psychiatric disease and signs of central nervous system (CNS) pathology (e.g.

Evaluation of [C]UCB-A positron emission tomography in human brains.

Background: In preclinical studies, the positron emission tomography (PET) imaging with [C]UCB-A provided promising results for imaging synaptic vesicle protein 2A (SV2A) as a proxy for synaptic density. This paper reports the first-in-human [C]UCB-A PET study to characterise its kinetics in healthy subjects and further evaluate SV2A-specific binding.

Results: Twelve healthy subjects underwent 90-min baseline [C]UCB-A scans with PET/MRI, with two subjects participating in an additional blocking scan with the same scanning procedure after a single dose of levetiracetam (1500 mg).

Striatal dopamine transporter and receptor availability correlate with relative cerebral blood flow measured with [C]PE2I, [F]FE-PE2I and [C]raclopride PET in healthy individuals.

The aim of this retrospective study was to investigate relationships between relative cerebral blood flow and striatal dopamine transporter and dopamine D2/3 availability in healthy subjects. The data comprised dynamic PET scans with two dopamine transporter tracers [C]PE2I (n = 20) and [F]FE-PE2I (n = 20) and the D2/3 tracer [C]raclopride (n = 18). Subjects with a [C]PE2I scan also underwent a dynamic scan with the serotonin transporter tracer [C]DASB.

The deletion causes early onset autosomal dominant Alzheimer's disease by altering APP processing and increasing amyloid β fibril formation.

Point mutations in the amyloid precursor protein gene () cause familial Alzheimer's disease (AD) by increasing generation or altering conformation of amyloid β (Aβ). Here, we describe the mutation (Δ690-695), the first reported deletion causing autosomal dominant AD. Affected individuals have an age at symptom onset in their early forties and suffer from a rapidly progressing disease course.

Evaluation of Arterial Spin Labeling MRI-Comparison with O-Water PET on an Integrated PET/MR Scanner.

Cerebral blood flow (CBF) measurements are of high clinical value and can be acquired non-invasively with no radiation exposure using pseudo-continuous arterial spin labeling (ASL). The aim of this study was to evaluate accordance in resting state CBF between ASL (CBF) and O-water positron emission tomography (PET) (CBF) acquired simultaneously on an integrated 3T PET/MR system. The data comprised ASL and dynamic O-water PET data with arterial blood sampling of eighteen subjects (eight patients with focal epilepsy and ten healthy controls, age 21 to 61 years).

Image reconstruction methods affect software-aided assessment of pathologies of [F]flutemetamol and [F]FDG brain-PET examinations in patients with neurodegenerative diseases.

Purpose: To assess how some of the new developments in brain positron emission tomography (PET) image reconstruction affect quantitative measures and software-aided assessment of pathology in patients with neurodegenerative diseases.

Methods: PET data were grouped into four cohorts: prodromal Alzheimer's disease patients and controls receiving [F]flutemetamol, and neurodegenerative disease patients and controls receiving [F]FDG PET scans. Reconstructed images were obtained by ordered-subsets expectation maximization (OSEM; 3 iterations (i), 16/34 subsets (s), 3/5-mm filter, ±time-of-flight (TOF), ±point-spread function (PSF)) and block-sequential regularized expectation maximization (BSREM; TOF, PSF, β-value 75-300).

Phenotypic variability in chorea-acanthocytosis associated with novel mutations.

Objective: To perform a comprehensive characterization of a cohort of patients with chorea-acanthocytosis (ChAc) in Sweden.

Methods: Clinical assessments, targeted genetic studies, neuroimaging with MRI, [F]-fluorodeoxyglucose (FDG) PET, and dopamine transporter with I FP-CIT (DaTscan) SPECT. One patient underwent magnetic resonance spectroscopy (MRS).

Z-score maps from low-dose F-FDG PET of the brain in neurodegenerative dementia.

Neuroimaging is a central part of diagnostic work-up of patients with suspected neurodegenerative disease. FDG-PET can reveal pathological changes earlier and more reliably than morphological imaging. Diagnostic accuracy can be improved by constructing 3D SSP Z-score maps, showing patterns of significant deficits.

Region-by-region analysis of PET, MRI, and histology in en bloc-resected oligodendrogliomas reveals intra-tumoral heterogeneity.

Purpose: Oligodendrogliomas are heterogeneous tumors in terms of imaging appearance, and a deeper understanding of the histopathological tumor characteristics in correlation to imaging parameters is needed. We used PET-to-MRI-to-histology co-registration with the aim of studying intra-tumoral C-methionine (MET) uptake in relation to tumor perfusion and the protein expression of histological cell markers in corresponding areas.

Methods: Consecutive histological sections of four tumors covering the entire en bloc-removed tumor were immunostained with antibodies against IDH1-mutated protein (tumor cells), Ki67 (proliferating cells), and CD34 (blood vessels).

Evaluation of Penalized-Likelihood Estimation Reconstruction on a Digital Time-of-Flight PET/CT Scanner for F-FDG Whole-Body Examinations.

The resolution and quantitative accuracy of PET are highly influenced by the reconstruction method. Penalized-likelihood estimation algorithms allow for fully convergent iterative reconstruction, generating a higher image contrast than ordered-subsets expectation maximization (OSEM) while limiting noise. In this study, a type of penalized reconstruction known as block-sequential regularized expectation maximization (BSREM) was compared with time-of-flight OSEM (TOF OSEM).

Development of a clinically feasible [C]PE2I PET method for differential diagnosis of parkinsonism using reduced scan duration and automated reference region extraction.

[C]PE2I is a highly selective dopamine transporter PET ligand. Parametric images based on dynamic [C]PE2I scans, showing dopamine transporter availability (BP) and relative cerebral blood flow (R), can be used in differential diagnosis of parkinsonism. This work aimed to investigate a shortened scan duration and automated generation of parametric images which are two prerequisites for routine clinical application.

Arterial spin labeling-based Z-maps have high specificity and positive predictive value for neurodegenerative dementia compared to FDG-PET.

Objective: Cerebral perfusion analysis based on arterial spin labeling (ASL) MRI has been proposed as an alternative to FDG-PET in patients with neurodegenerative disease. Z-maps show normal distribution values relating an image to a database of controls. They are routinely used for FDG-PET to demonstrate disease-specific patterns of hypometabolism at the individual level.

Validation of true low-dose F-FDG PET of the brain.

The dosage of F-FDG must be sufficient to ensure adequate PET image quality. For younger patients and research controls, the lowest possible radiation dose should be used. The purpose of this study was to find a protocol for FDG-PET of the brain with reduced radiation dose and preserved quantitative characteristics.

Long-term evaluation of the effect of hypofractionated high-energy proton treatment of benign meningiomas by means of (11)C-L-methionine positron emission tomography.

Purpose: To determine if (11)C-L-methionine PET is a useful tool in the evaluation of the long-term effect of proton beam treatment in patients with meningioma remnant.

Methods: Included in the study were 19 patients (4 men, 15 women) with intracranial meningioma remnants who received hypofractionated high-energy proton beam treatment. Patients were examined with (11)C-L-methionine PET and MRI prior to treatment and after 6 months, and 1, 2, 3, 5, 7 and 10 years.

Visual Assessment of Brain Perfusion MRI Scans in Dementia: A Pilot Study.

Purpose: Functional imaging is becoming increasingly important for the detection of neurodegenerative disorders. Perfusion MRI with arterial spin labeling (ASL) has been reported to provide promising diagnostic possibilities but is not yet widely used in routine clinical work. The aim of this study was to compare, in a clinical setting, the visual assessment of subtracted ASL CBF maps with and without additional smoothing, to FDG-PET data.

Seizure outcomes in relation to the extent of resection of the perifocal fluorodeoxyglucose and flumazenil PET abnormalities in anteromedial temporal lobectomy.

Background: The area of predominant perifocal [(18)F]fluorodeoxyglucose ((18)F-FDG) hypometabolism and reduced [(11)C]flumazenil ((11)C-FMZ) -binding on PET scans is currently considered to contain the epileptogenic zone and corresponds anatomically to the area localizing epileptogenicity in patients with temporal lobe epilepsy (TLE). The question is whether the volume of the perifocal pre-operative PET abnormalities, the extent of their resection, and the volume of the non-resected abnormalities affects the post-operative seizure outcome.

Methods: The sample group consisted of 32 patients with mesial temporal sclerosis who underwent anteromedial temporal lobe resection for refractory TLE.

Use of 11C-PE2I PET in differential diagnosis of parkinsonian disorders.

Unlabelled: In idiopathic Parkinson disease and atypical parkinsonian disorders, central dopaminergic and overall brain functional activity are altered to different degrees, causing difficulties in achieving an unambiguous clinical diagnosis. A dual examination using (123)I-FP-CIT ((123)I-N-ω-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl)nortropane, or (123)I-ioflupane) SPECT and(18)F-FDG PET provides complementary information on dopamine transporter (DAT) availability and overall brain functional activity, respectively. Parametric images based on a single, dynamic (11)C-PE2I (N-(3-iodoprop-2E-enyl)-2β-carbomethoxy-3β-(4-methyl-phenyl)nortropane) scan potentially supply both DAT availability (nondisplaceable binding potential [BPND]) and relative cerebral blood flow (relative delivery [R1]) at voxel level.

Validation of parametric methods for [¹¹C]PE2I positron emission tomography.

Objectives: The radioligand [(11)C]PE2I is highly selective for dopamine transporter (DAT) and can be used in vivo for investigation of changes in DAT concentration, progression of disease and validation of treatment using positron emission tomography (PET). DAT is an important protein for regulation of central dopamine concentration and DAT deficiency has been associated with several neurodegenerative and neuropsychiatric disorders. Accurate parametric images are a prerequisite for clinical application of [(11)C]PE2I.

PET response and tumor stabilization under erlotinib and bevacizumab treatment of an intracranial lesion non-invasively diagnosed as likely chordoma.

Introduction: Chordoma is a rare and a slow-growing tumor originating from the notochord and commonly localized in the skull base. Surgery and occasionally radiotherapy have emerged as the treatments of choice. In the relapsed situations available treatment options are strictly limited; however, recently molecularly targeted agents have been proposed to be of potential beneficial value.

Increased neurokinin-1 receptor availability in temporal lobe epilepsy: a positron emission tomography study using [(11)C]GR205171.

Purpose: Activation of the neurokinin-1 (NK1) receptor by neuropeptide substance P (SP) induces and maintains epileptic activity in various experimental models of epilepsy. The primary objective of this study was to investigate whether neurobiological changes linked to NK1-SP receptor system are associated with hyperexcitability in patients with temporal lobe epilepsy (TLE). A secondary objective was to investigate the relationship between seizure frequency and NK1 receptor availability.

Clinical, neuroimaging and neurophysiological features in addicts with manganese-ephedrone exposure.

Objective: To identify biomarkers supporting the clinical diagnosis of manganism in patients several years after exposure to manganese (Mn).

Methods: Neurophysiological examinations, magnetic resonance imaging (MRI), single-photon emission computed tomography and fluorodeoxyglycose (FDG) positron emission tomography were performed in four former ephedrone addicts with extrapyramidal symptoms.

Results: Peripheral nervous system was not affected.

Epileptic seizures and survival in early disease of grade 2 gliomas.

Background And Purpose: The aims of this study were (i) to determine the correlation between seizure activity and the metabolic rate of the tumour measured by (11)C-methionine PET (MET PET) in patients with grade 2 gliomas, and (ii) to assess the prognostic impact of early seizure manifestations on patient survival.

Methods: In this retrospective review, early seizure manifestations were studied in 101 patients with supratentorial grade 2 gliomas subjected to MET PET as part of the pre-treatment tumour investigation. Seizure manifestations as a variable was then used in multivariate survival analyses, together with established prognostic factors for this patient group.

Tetrahydrobiopterin in the treatment of children with autistic disorder: a double-blind placebo-controlled crossover study.

Twelve children, all boys, aged 4 to 7 years, with a diagnosis of autistic disorder and low concentrations of spinal 6R-l-erythro-5,6,7,8-tetrahydrobiopterin (tetrahydrobiopterin) were selected to participate in a double-blind, randomized, placebo-controlled, crossover study. The children received a daily dose of 3 mg tetrahydrobiopterin per kilogram during 6 months alternating with placebo. Treatment-induced effects were assessed with the Childhood Autism Rating Scale every third month.

Positron emission tomography with 11C-D-deprenyl in patients with rheumatoid arthritis. Evaluation of knee joint inflammation before and after intra-articular glucocorticoid treatment.

Seven patients with arthritic disease and with clinical signs of inflammation of the knee joint, were investigated with positron emission tomography (PET) after injection of [N-methyl-11C]-D-deprenyl. Two healthy volunteers were included as controls. In five patients the investigation was repeated after an intra-articular injection of glucocorticoids.