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Biomedical subjects

N Tonami

Publications and source records attributed to N Tonami.

At least 253 records · Page 14Linked to original sources
PubMed1986

Length-based Fourier analysis in the pre-excitation syndrome.

Length-based Fourier analysis (LFA) was applied to tomographic gated blood-pool study, and phase and percent-shortening diagrams were generated. In 22 patients with pre-excitation syndrome and ten control subjects, the most basal short-axis section was used for tomographic analysis. When the initial abnormal phase was considered as the location of accessory conduction pathway (ACP), correct diagnosis for the localization of ACP was given in 19 of 22 patients. In ten control subjects, no specific segments of initial phase were noted, although six patients had initial phase in the septal or paraseptal segments. The tomographic LFA was more effective for pinpointing the segment of the earliest phase than tomographic count-based phase analysis. The LFA provided objective three-dimensional information for contraction sequence. Because movements of ventricular edges are essential in tomography, the LFA was considered to be a reasonable approach for the analysis of tomographic gated blood-pool study.

Erythrocytes↗
PubMed1986

Multicompartmental analysis of the kinetics of radioiodinated monoclonal antibody in patients with cancer.

A conceptual biologic model was developed and used to analyze the behavior of 123I-Lym-1 monoclonal antibody against African human B cell lymphoma in patients with B cell lymphoma. Originally, the observed data could not be simulated with parameters for homologous immunoglobulins reported in the literature because of a major processor that was capable of distinguishing this murine immunoglobulin from the patient's own immunoglobulins. With a nonlinear parametric model, the data observed in patients could be fitted to the model. The nonlinear parameter determined the transfer of antibody from the intravascular to a processor compartment, primarily the liver. This transfer was a function of the number of free receptors in the processor. Model simulated curves for the time course of concentration of antibody in the blood for different amounts of injected antibody revealed that blood clearance of radiolabeled antibody was profoundly decreased by increased amount of injected antibody. This model provides an explanation for the observations that tumor imaging is improved with injection of larger amounts of antibody, and a basis for modifying the pharmacokinetic behavior of an antibody in order to optimize radioimmunodiagnosis and radioimmunotherapy.

Antibodies, Monoclonal↗
PubMed1986

Quantitative cerebral blood flow measurements using N-isopropyl-(iodine 123) p-iodoamphetamine and single photon emission computed tomography with rotating gamma camera.

Sixty regional cerebral blood flow measurements were performed on 4 normal volunteers, 7 epileptics, and 40 cerebrovascular disorders using intravenously injected N-isopropyl-(I-123)p-iodoamphetamine (123I-IMP) and single photon emission computed tomography with rotating gamma camera. Arterial blood sampling was combined for obtaining absolute blood flow values. The brain activity distributions of the tomographic image from 30 min after injection, when brain activity reached a plateau, were corrected to represent 5-min reference values with the use of the monitored entire brain's time-activity curve. Brain mean blood flow values ranged from 54 to 63, 34 to 59, and 20 to 60 ml/100 g/min, in normal volunteers, epileptics, and subjects with cerebrovascular disorders, respectively. Brain mean 123I-IMP uptake corrected for injection dose did not correlate with these absolute flow values. This quantitative method is especially useful for diagnosing diffuse flow reductions, which were observed in 8 (14%) of 56 studies in the patients.

Adolescent↗
PubMed1985

Nuclear tomographic phase analysis: localization of accessory conduction pathway in patients with Wolff-Parkinson-White syndrome.

The purpose of this study was to evaluate the usefulness of tomographic phase analysis in detecting the site of the accessory conduction pathway (ACP) in patients with Wolff-Parkinson-White (WPW) syndrome. Gated emission computed tomography and planar gated blood pool scintigraphy were performed in 20 patients with WPW syndrome, 14 with delta waves and six without delta waves (two intermittent types and four concealed types). The abnormal initial contractions in both planar and tomographic phase images were compared with the sites of ACPs confirmed by epicardial mapping and surgery. The atrioventricular ring was divided into eight segments on each side, and the identification of the initial phase in the segment in which the ACP was located, or that adjacent to it, was considered to be the correct diagnosis. In planar phase analysis, the abnormal initial phase was identified correctly in 8 of 14 patients (57%), whereas in tomographic phase analysis, the site of the ACP was detected in 12 of 14 patients (86%). Tomographic phase analysis can be a helpful adjunctive method in patients with WPW syndrome.

Adolescent↗
PubMed1985

201Tl per-rectal scintigraphy in primary hepatocellular carcinoma.

The results of 201Tl per-rectal scintigraphy in 10 patients with primary hepatocellular carcinoma (HCC) were presented together with the findings from contrast angiography, computed tomography and ultrasonography. 201Tl accumulation within the tumour was seen in seven of ten patients. This accumulation was thought to be due to 201Tl supply not from the portal vein but from the hepatic artery since significantly high heart to liver uptake (H/L) ratio from 0.71 to 1.21 and clear visualization of the heart and kidneys, indicating the presence of abundant portal-to-systemic shunting, were observed. Another three patients showed negative 201Tl accumulation within the tumour and near-normal H/L ratios from 0.32 to 0.47 which indicates little portal-to-systemic shunting. This finding reveals the evidence of the lack of 201Tl supply to the tumour from the portal vein. It seems that HCC does not receive any significant amount of blood flow from the portal system.

Administration, Rectal↗