Search results for " Single-Photon"
showing 10 items of 36 documents
Contribution of thallium-201-SPECT to the grading of tumorous alterations of the brain
1992
Single photon emission computed tomography (SPECT) with thallium-201-chloride (201Tl) was used in 22 patients to assess the grade of malignancy of brain tumors. Low- and high-grade malignant gliomas could be well differentiated by calculating the Grade Index (GI), i.e., 201Tl uptake in the tumor area relative to a contralateral brain region. Low-grade gliomas (WHO-grade I-II) usually showed a GI of1.5. Tumors classified histologically as high-grade malignant (WHO-grade III-IV) had GI values greater than 1.42 and a mean value of 1.89. Until labelled amino-acid tracers for gamma-cameras become commercially available, thallium-201 brain-SPECT can provide an independent and complementary method…
Usefulness of N-terminal pro-B-type natriuretic peptide levels in predicting residual myocardial ischemia in patients with ST elevation acute myocard…
2007
N-terminal pro-b-type natriuretic peptide (NT pro-BNP) is a neurohormone synthesized predominantly in ventricular myocardium. In patients with symptoms of heart failure, elevation in NT pro-BNP accurately identifies ventricular dysfunction. However, NT pro-BNP levels are not specific for ventricular dysfunction in patients who do not have overt symptoms of heart failure, suggesting that other cardiac processes such as myocardial ischemia may also cause elevation in NT pro-BNP. The study was aimed to determine whether NT pro-BNP elevations are associated with myocardial ischemia.One hundred and thirty patients (104 males, 26 females, mean age 61+12 years), with ST elevation acute myocardial …
Dynamic image denoising for voxel-wise quantification with Statistical Parametric Mapping in molecular neuroimaging.
2018
Purpose PET and SPECT voxel kinetics are highly noised. To our knowledge, no study has determined the effect of denoising on the ability to detect differences in binding at the voxel level using Statistical Parametric Mapping (SPM). Methods In the present study, groups of subject-images with a 10%- and 20%- difference in binding of [123I]iomazenil (IMZ) were simulated. They were denoised with Factor Analysis (FA). Parametric images of binding potential (BPND) were produced with the simplified reference tissue model (SRTM) and the Logan non-invasive graphical analysis (LNIGA) and analyzed using SPM to detect group differences. FA was also applied to [123I]IMZ and [11C]flumazenil (FMZ) clinic…
Decreased benzodiazepine receptor binding in panic disorder measured by IOMAZENIL-SPECT. A preliminary report.
1994
Single photon emission tomography (SPECT) imaging of the central benzodiazepine receptor (BZr) became possible with the newly developed ligand 123I-IOMAZENIL. The BZr binding was investigated in ten patients with panic disorder (PP) compared to ten epileptic patients (EP). Panic patients had lower IOMAZENIL uptake rates in the frontal, occipital and temporal cortex than EP indicating the involvement of the BZr complex in panic disorder.
Correlation of cerebral blood flow and treatment effects of repetitive transcranial magnetic stimulation in depressed patients.
2002
The aims of this study were to: (1) assess the effects of repetitive transcranial magnetic stimulation (rTMS) on brain activity in depressed patients as measured by single photon emission tomography (SPECT); (2) evaluate the predictive value of brain SPECT on the antidepressant efficacy of rTMS. Patients (n=17) received 1600 rTMS stimuli at a rate of 10 Hz, 5 days per week for 2 weeks to the left dorsolateral prefrontal cortex. Whole brain SPECT data were acquired using Tc99m-Bicisate. Regional cerebral blood flow (rCBF) was correlated with the % change in the 28-item Hamilton Depression Rating Scale Score (Δ-HDRS) and a semiquantitative region of interest (ROI) analysis was conducted. Prio…
Somatostatin-receptor scintigraphy in Graves' disease: reproducibility and variance of orbital activity.
2000
Somatostatin-receptor (SSTR) scintigraphy using the single photon emission computed tomography (SPECT) technique allows the assessment of orbital inflammation in patients with Graves' disease. Previous studies showed differences in orbital octreotide uptake already 4 hr after injection. In this study, analysis of inter-/intra-observer variance and reproducibility in the evaluation of orbital SPECT images was performed. First, SPECT data of one representative female patient with clinically active Graves' ophthalmopathy (GO), obtained 4 hr after intravenous injection of 110 MBq 111In-pentetreotide and processed by filtered backprojection, were analyzed. Transverse SPECT images were reconstruc…
Noninvasive assessment of Crohn's disease activity: a comparison of 18F-fluorodeoxyglucose positron emission tomography, hydromagnetic resonance imag…
2002
Detection of disease activity in Crohn's disease (CD) is of crucial importance for diagnosis and management of the disease. Noninvasive methods for monitoring are desirable and comprise hydromagnetic resonance imaging (hydro-MRI) and leukocyte scintigraphy. In addition, a recent case report indicated the potential of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) to assess CD activity. However, comparative prospective studies are lacking.Between February, 1999 and August, 2000, 59 patients with CD were enrolled in a prospective study to assess disease activity by FDG-PET, hydro-MRI, and immunoscintigraphy with anti-nonspecific cross-reacting antigen 95 antigranulocyte antibod…
Role of Octreoscan and Correlation with MR Imaging in Graves' Ophthalmopathy
1995
Since the identification of somatostatin receptors on lymphocytes, orbital infiltration with mononuclear cells in Graves' ophthalmopathy has provided a rationale for receptor imaging with the radiolabeled somatostatin analog Octreotide. In 40 patients with Graves' ophthalmopathy and 10 controls, 110 MBq indium-Octreotide were administered i.v., and scans were performed at 4 and 24 h after injection. An uptake ratio between the orbits and the brain was determined. In 20 ophthalmophathy patients, magnetic resonance imaging (MRI) of the orbits was performed and the T2 relaxation time was measured within the rectus muscles. Compared to controls (4 h Octreotide uptake: median 6.0 counts/pixel/MB…
[123I]IBZM SPECT in patients treated with typical and atypical neuroleptics: relationship to drug plasma levels and extrapyramidal side effects
1997
[123I]Iodobenzamide (IBZM) is an iodine-labeled dopamine receptor ligand and can be used to visualize brain D2 receptors in humans with single photon emission computerized tomography (SPECT). The ratio of striatal IBZM uptake to uptake in frontal cortex (ST/FC ratio) represents a semiquantitative measure of D2 receptor binding in the striatum. Our study sample included six patients treated with haloperidol (3.0-8.0 mg/day orally; one patient with an average of 0.9 mg/day intramuscularly), five patients with benperidol (9.0-15.0 mg/day orally) and nine patients treated with clozapine (200.0-600.0 mg/day orally). Typical neuroleptics (TNs) and atypical neuroleptics (ANs) were significantly di…
Dissociation of emotional processes in response to visual and olfactory stimuli following frontotemporal damage.
2005
Contemporary neuropsychological studies have stressed the widely distributed and multicomponential nature of human affective processes. Here, we examined facial electromyographic (EMG) (zygomaticus and corrugator muscle activity), autonomic (skin conductance and heart rate) and subjective measures of affective valence and arousal in patient TG, a 30 year-old man with left anterior mediotemporal and left orbitofrontal lesions resulting from a traumatic brain injury. Both TG and a normal control group were exposed to hedonically valenced visual and olfactory stimuli. In contrast with control subjects, facial EMG and electrodermal activity in TG did not differentiate among pleasant, unpleasant…