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Biomedical subjects

T Iinuma

Publications and source records attributed to T Iinuma.

At least 91 records · Page 5Linked to original sources
PubMed1988

Fundamental tumor perfusion analysis with nuclear magnetic resonance imaging using gadolinium-diethylene triamine pentaacetic acid.

The measurement of blood perfusion is an important factor for both the diagnosis and follow-up of tumor lesions. However, noninvasive detection of this local blood flow factor is very difficult. To accomplish this, we tried to calculate tissue blood perfusion indexes with nuclear magnetic resonance imaging using gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA). We experimentally applied this method to C3H mouse's tumor NFSa (fibrosarcoma) and its recurrence tumor R1137, whose experimental hypoxic cell fraction is different; that is, R1137 is more oxic than NFSa. Imaging pulse sequence was T1 (TR = 1,000 ms, TI = 300 ms), and longitudinal relaxation rate (R1 = 1/T1) values were calculated. Injected dose of Gd-DTPA was 0.1 mmol/kg. The T1 images produced are from both the preinjection period from every 5 min postinjection for 30 min. Using two-exponential analysis and compartment analysis we calculated two fundamental parameters: uptake index and flow index as blood perfusion factors. We found that this method has the possibility of differentiating the tissue's hypoxic cell fraction and is effective both for follow-up study after radiation therapy and for tissue characterization.

Animals↗
PubMed1987

[A cooperative group study of clinical efficacy of the liver SPECT].

The purpose of this study is to evaluate the clinical efficacy of the liver SPECT about detectability of SOLs (space occupying lesion). The images were interpreted with the planar scintigram (PS) only and combination of PS and SPECT (single photon emission computed tomography) by 11 physicians. Changes of false positive and false negative rate were calculated to evaluate the influence of the diffuse parenchymal liver disease and the localization of the SOLs. Addition of SPECT to PS in the cases who are suspected SOLs is effective in right hepatic lobe (right anterior and posterior segment) to detect the SOLs, but not effective in left lateral segment. Addition of SPECT to PS in the cases with diffuse parenchymal liver disease and SOLs increases the false positive rate.

Chronic Disease↗
PubMed1986

Fast dynamic study in cardiac positron CT using 13N-ammonia in man.

Fast dynamic studies with positron computed tomography (PCT) of the heart have been relatively few because of the technical limitations of prevalently used PCT devices. In the present study, we used a high-sensitivity, whole-body multislice PCT device (POSITOLOGICA-II) and performed serial 6-s PCT scans after the intravenous bolus injection of 13N-ammonia in 15 cardiac patients and 5 normal subjects. On the first image (0-6 s), 13N activity was primarily in the right atrium and ventricle. On the third image (12-18 s), it was primarily in the left atrium and ventricle. These blood-pool images permit evaluation of size and configuration of ventricles and atria in cardiac patients and normal subjects. Clearance of 13N activity in the blood pools and lungs occurred primarily during the 1st min. Thereafter, the myocardial images were delineated. In patients with heart failure, delayed clearance of the tracer from the blood pools and lungs was observed. The results indicate that initial passage of the tracer through the heart can be observed with the use of fast dynamic PCT.

Adult↗