Increased activation of the central benzodiazepine receptor (BZR) appears to play an important role in hepatic encephalopathy (HE). However, there is controversy regarding whether the density or affinity of BZRs is altered. A previous positron emission tomography (PET) study using the BZR antagonist [11C]flumazenil (FMZ) found two- to threefold greater cerebral cortical tracer uptake in recurre...

Immuno-PET imaging of the tumor antigen HER2/neu allows for the noninvasive detection and monitoring of oncogene expression; such detection and monitoring are of prognostic value in patients with breast cancer. Compared with the full-size antibody trastuzumab, smaller protein tracers with more rapid blood clearance permit higher imaging contrast at earlier time points. Antigen-binding fragments...

UNLABELLED Phosphodiesterases are enzymes that inactivate the intracellular second messengers 3',5'-cyclic adenosine-monophosphate and/or cyclic guanosine-monophosphate. Of all 11 known phosphodiesterase families, phosphodiesterase-10A (PDE10A) has the most restricted distribution, with high expression in the striatum. PDE10A inhibitors are pursued as drugs for treatment of neuropsychiatric dis...

Herpes simplex virus type 1 (HSV-1) is one of the most common causes of sporadic encephalitis. The initial clinical course of HSV encephalitis (HSE) is highly variable, and the infection may be rapidly fatal. For effective treatment with antiviral medication, an early diagnosis of HSE is crucial. Subtle brain infections with HSV may be causally related to neuropsychiatric disorders such as Alzh...

The present most common image diagnostic tracer in clinical practice for glioma is 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) for brain tumors diagnosis and prognosis. PET is a promising molecular imaging technique, which provides real-time information on the metabolic behavior of the tracer. The diffusive nature of glioblastoma (GBM) and heterogeneity often make the radiog...

Non-invasive positron emission tomography (PET) enables the measurement of metabolic and molecular processes with high sensitivity. PET plays a significant role in the diagnosis, prognosis, and treatment of brain tumors and predominantly detects brain tumors by detecting their metabolic alterations, including energy metabolism, amino acids, nucleic acids, and hypoxia. Glucose metabolic tracers ...

A 93-year-old woman presented with a 3 ¥ 3 cm ulcerous lesion on the lateral side of her right lower leg. Biopsy confirmed the diagnosis of malignant melanoma. PET/CT imaging was performed for staging of this high risk melanoma patient. The plasma glucose level of the patient was 93 mg/dl before the tracer injection. PET/CT whole-body imaging was performed at 120 minutes after the intravenous i...

BACKGROUND Gangliogliomas involving the optic nerve or chiasm are extremely rare tumors, which can be confused radiologically with other neoplasms. α-[N-methyl-11C]-methylaminoisobutyric acid (11C-MeAIB) is a new artificial amino acid positron emission tomography (PET) tracer, which is metabolically more stable in vivo and may be more specific for tumors than 11C-methionine. However, the utilit...

The dopaminergic system plays a major role in neurological and psychiatric disorders such as Parkinson's disease, Huntington's disease, tardive dyskinea and schizophrenia. Knowledge on altered dopamine synthesis, receptor densities and status are important for understanding the mechanisms underlying the pathogenesis and therapy of diseases. PET provides a non-invasive tool to investigate these ...

Metallic implants are known to generate bright and dark streaking artifacts in x-ray computed tomography (CT) images, which in turn propagate to corresponding functional positron emission tomography (PET) images during the CT-based attenuation correction procedure commonly used on hybrid clinical PET/CT scanners. Therefore, visual artifacts and overestimation and/or underestimation of the trace...