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Biomedical subjects

Y Futagami

Publications and source records attributed to Y Futagami.

48 records · Page 3Linked to original sources
PubMed1985

[Quantitative analysis of aortic regurgitation using radionuclide phase analysis].

In this study, the clinical utility of phase analysis using gated blood pool scintigraphy to detect aortic regurgitation (AR) was assessed. The study population included 33 patients with AR documented by cineaortography, and 53 patients without AR diagnosed by clinical features and pulsed Doppler echocardiography or cineaortography. Gated blood pool images were stored in modified left anterior oblique views by the multiple gated method (28 frames per beat) after the in vivo labeling of erythrocytes using 25 mCi 99m-Tc. Amplitude was depressed at the subaortic region toward the apex in patients with AR, and occasionally the phase angle occurred earlier in the same region. This is because diastolic filling began earlier and stroke count was decreased more in the subaortic region than in other regions of the left ventricle in examining the regional time-activity curve. Based on this characteristic finding in the amplitude image, the specificity was 81% and the sensitivity was 79% in the diagnosis of AR. The degree of AR was estimated using the amplitude image as follows: grade 1, depression of amplitude localized to the subaortic region; grade 2, depression of amplitude detected from the subaortic region to the midportion of the left ventricle; grade 3, depression of amplitude detected beyond the midportion of the left ventricle. We compared results with those of the radionuclide (RI's classification) and angiographic methods (Sellers' classification) as to the severity of AR. AR could not be detected using the radionuclide method in all four patients with Sellers' grade 1, and in three of nine patients with Sellers' grade 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Valve Insufficiency↗
PubMed1985

[Detection of thrombi by 111In-oxine platelet scintigraphy].

For 52 patients with cardiac disease and 11 patients with vascular disease, In-111-oxine platelet scintigraphy was performed to assess its clinical usefulness for detecting thrombi. Using Hayashida's method, platelets were separated in 43 ml peripheral blood, washed and labeled with 1 mCi In-111-oxine. In addition to planar images in the anterior, 45 degrees left anterior oblique and left lateral views, single photon emission computed tomography (SPECT) was performed in some cases by rotating a dual gamma camera 24 and 72 hours after labeled platelet injection. The functions of platelet and coagulability were examined 36 hours after the injection of labeled platelets. Medical therapy was not changed during this study. Intracardiac thrombi were documented in 16 of 52 cases with cardiac disease and intravascular thrombi in 10 cases with vascular disease by angiography, CT and two-dimensional echocardiography. Positive images were obtained in 10 cases with cardiac disease and in eight cases with vascular disease by scintigraphy. Therefore, sensitivity, specificity, and overall accuracy were 63%, 100% and 88% in intracardiac thrombi; 80%, 100% and 82% in intravascular thrombi; and totally 69%, 100% and 87%, respectively. In the detection of intracardiac thrombi by scintigraphy, the sensitivity seemed to be lower and the specificity higher than those by other graphic studies. In 52 cases with cardiac disease, five out of six cases with false negative images had received antiplatelet and/or anticoagulant drugs, and in these cases, platelet and coagulation functions tended to be decreased compared with those of true positive cases or true negative cases. We conclude that positive images in scintigraphy indicate the existence of growing thrombi, and that In-111-oxine platelet scintigraphy has clinical usefulness, not only for detecting thrombi, but for estimating platelet activity and effect of medical therapy.

Blood Platelets↗
PubMed1983

[Detectability of stress-induced ischemic lesion in previous myocardial infarction using 201T1 myocardial single photon emission computed tomography].

The purpose of this study was to evaluate the detectability of stress-induced ischemic lesion in patients with previous myocardial infarction using single photon emission computed tomography (SPECT) producing thallium-201 (T1-201) myocardial perfusion imagings (MPI). Seventy patients underwent stress SPECT by symptom-limited graded bicycle ergometer exercise using a dual-headed rotating gamma camera (Toshiba GCA70A) equipped with a computer system (GMS90). After intravenous administration of 2.5 mCi of T1-201, stress SPECT data at 10 minutes and delayed SPECT data at 3 hours after the injection were collected in the 64 X 64 matrix form covering 360 degrees directions by camera sweep of 180 degrees in 6 minutes, which were immediately followed by conventional planar imagings (PL). Transaxial tomographic image reconstruction was performed by convolution method using a Shepp-Logan's filter. Thereafter, sagittal and coronal tomographic images were reconstructed for about 2 minutes. Image interpretation was assessed visually. The results were as follows: Sensitivity and specificity in detecting the affected vessel with more than 75% stenosis by segmental analysis of myocardial images were higher by SPECT than by PL (LAD 89% and 65%, LCX 68% and 56%, RCA 89% and 76% in sensitivity and LAD 94% and LCX 75%, 92% and 94%, RCA 81% and 59% in specificity, respectively). Sensitivity in detecting both single (82%) and multivessel disease (76%) was fairly high. Detectability of stress-induced ischemia (i.e. occurrence of a new defect in patients with previous myocardial infarction and ST-segment depression in ECG) was significantly higher in SPECT (67%) than in PL (39%, p less than 0.005) and in ECG (39%, p less than 0.005). A perfusion defect in the extensive anterior wall, marked left ventricular dilatation and the widening of the angle toward the apex composed of septal and anterolateral walls in transaxial images were the findings characteristic of anterior myocardial infarction with severe dyskinesis. We conclude that stress SPECT is a useful noninvasive technique for the documentation of the number of vessels affected and severe wall motion abnormality of the LV and for the detection of stress-induced ischemia in previous myocardial infarction.

Electrocardiography↗