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Positron Emission Tomography Studies (positron + emission_tomography_studies)
Selected AbstractsRecent development and potential use of µ- and ,-opioid receptor ligands in positron emission tomography studiesDRUG DEVELOPMENT RESEARCH, Issue 12 2006Gjermund Henriksen Abstract Quantitative non-invasive imaging of target structures in the human central nervous system provided by positron emission tomography (PET) permits investigation of the relationship between molecular events and pharmacological effects in living humans. Due to their prominent role in opiate and stimulant drug misuse and dependence, as well as in nociceptive signaling, µ- and ,-opioid receptors are potential targets for advances in neuro(psycho)pharmacological treatment of these illnesses and syndromes. In this review, we describe recent developments in specific positron emitting radiopharmaceuticals for these opioid receptor subclasses. Implications for further advances and clinical applications of the labeled ligands are discussed. Drug Dev. Res. 67:890,904, 2006. © 2007 Wiley-Liss, Inc. [source] Possible sporadic rapid-onset dystonia,parkinsonism,MOVEMENT DISORDERS, Issue 3 2002Gurutz Linazasoro MD Rapid-onset dystonia,parkinsonism is a hereditary disease characterized by a combination of dystonic and parkinsonian symptoms. Bulbar musculature is predominantly affected by dystonia. The onset is usually abrupt and the progression of the disease over years is minimal or absent. Homovanillic acid levels in cerebrospinal fluid can be diminished, suggesting that the pathogenesis of the disease is related to some dysfunction in dopaminergic neurotransmission. However, no abnormality has been found in positron emission tomography studies and levodopa does not improve symptoms. The genetic abnormality is not known, but evidence for linkage to markers on chromosome 19q13 has been reported. We describe the case of a woman with a clinical picture highly suggestive of rapid onset dystonia,parkinsonism (RDP) and no family history of the disease. © 2002 Movement Disorder Society. [source] Plasticity of language networks in patients with brain tumors: A positron emission tomography activation studyANNALS OF NEUROLOGY, Issue 5 2001Alexander Thiel MD We investigated plasticity of language networks exposed to slowly evolving brain damage. Single subject O-15-water language activation positron emission tomography studies were analyzed in 61 right-handed patients with brain tumors of the left hemisphere, and 12 normal controls. In controls, activations were found in left Brodmann's Area (BA)44 and BA45, superior posterior temporal gyrus bilaterally, and right cerebellum. Patients additionally activated left BA46, BA47, anterior insula, and left cerebellum. Superior temporal activation was less frequent, and activations in areas other than posterior temporal gyrus were found bilaterally. Frontolateral activations within the nondominant hemisphere were only seen in patients (63%) with frontal or posterior temporal lesions. Laterality indices of frontolateral cortex showed reversed language dominance in 18% of patients. Laterality indices of the cerebellum were negatively correlated with language performance. Two compensatory mechanisms in patients with slowly evolving brain lesions are described: An intrahemispheric mechanism with recruitment of left frontolateral regions other than classic language areas; and an interhemispheric compensatory mechanism with frontolateral activation in the nondominant hemisphere. The latter one was only found in patients with frontal or posterior temporal lesions, thus supporting the hypothesis that right frontolateral activations are a disinhibition phenomenon. [source] Fluorodeoxyglucose positron emission tomography studies in the diagnosis and staging of clinically advanced prostate cancerBJU INTERNATIONAL, Issue 1 2003J. Sung OBJECTIVE To determine the value of 18F-fluoro-2-deoxyglucose (FDG) positron-emission tomography (PET) studies in evaluating patients with advanced prostate cancer. PATIENTS AND METHODS FDG-PET scans were taken in 30 patients with advanced prostate cancer 1 h after an injection with 555 MBq of FDG. Patients were scanned from the base of the skull to the inguinal region (including the pelvis). They were also assessed by computed tomography (CT) of the abdomen and pelvis, and bone scintigraphy, to evaluate them for metastases. RESULTS Thirteen patients had locally extensive prostate cancer and 17 had metastatic disease. Twenty of the 30 patients were positive for radioisotope uptake in the prostate or extraprostatically. The patients with PET-detected prostate cancer were untreated (seven), treated hormonally while they had rising PSA levels (eight), or treated hormonally with a detectable but stable PSA (five). The remaining 10 patients were negative for FDG uptake in the prostate or any metastatic sites; these 10 patients were receiving hormone therapy, with undetectable PSA levels. CONCLUSION FDG-PET imaging is not a useful test in evaluating advanced prostate cancer in patients being treated and who have an undetectable PSA level. Staging of advanced prostate cancer may be enhanced by FDG-PET imaging in patients who are untreated, who have had an incomplete response to therapy, or who have a rising PSA level despite treatment. [source] Distinguishing Parkinson's disease and essential tremor with transcranial sonographyACTA NEUROLOGICA SCANDINAVICA, Issue 1 2009M. Budisic Objectives,,, Until today there is no reliable test that can clearly distinguish Parkinson's disease (PD) from the essential tremor (ET). Our aim was to determine the usefulness of the transcranial sonography (TCS) in the differential diagnosis of the PD and ET as well as the interobserver reliability for this method. Methods,,, Transcranial sonography of substantia nigra and clinical examination were performed on 80 PD patients, 30 ET patients, and 80 matched controls by two independent physicians. Results,,, Bilateral SN hyperechogenicity over the margin of 0.20 cm2 was found in 91% of PD patients, 10% of healthy subjects, and in 13% patients with ET. Interobserver agreement for this method was significant (Student's t -test, P = 1.000). Conclusions,,, Substantia nigra hyperechogenicity on TCS is a highly specific finding of PD, where in healthy individuals or in ET patients, it might correspond to an increased risk of developing PD later in life or might also be because of the impairment of nearby area of nucleus ruber in ET patients, as suggested by positron emission tomography studies. TCS may serve as a practical and sufficiently sensitive neuroimaging tool in PD diagnoses and in distinguishing it from ET; its repeatability and accuracy might add to its practical value. [source] | ||||||||||