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Biomedical subjects

K Kusakabe

Publications and source records attributed to K Kusakabe.

At least 109 records · Page 6Linked to original sources
PubMed1986

Clinical validation of fully-automated contour detection for gated radionuclide ventriculography with a slant-hole collimator.

A new fully-automated method for processing gated blood-pool images is presented and its clinical validity and performance for images with various noise levels are investigated using data obtained from a slant-hole collimator. The optimal preprocessing conditions are evaluated for the images with various noise levels to obtain the accurate ejection fraction, end-diastolic and end-systolic counts. This new method has successfully detected left ventricular contour in 92% of the 61 patients. The left ventricular ejection fraction obtained by the method related closely to that of contrast ventriculography (correlation coefficient r = 0.90). The end-diastolic volume also had a good correlation with contrast ventriculography (r = 0.90).

Filtration↗
PubMed1985

Long follow-up study in patients with prior myocarditis by radionuclide methods.

Ten patients with previous myocarditis were evaluated to determine cardiac conditions by T1-201 myocardial perfusion imaging and stress radionuclide ventriculography during the follow-up of 18-102 (average 56) months; the results were compared with those from ten sex- and age-matched controls. Exercise capacity by supine bicycle ergometer was reduced in patients with myocarditis. Their resting left ventricular ejection fraction (LVEF) was 57.5% +/- 3.9%, similar to that of controls. LVEF response to stress in myocarditis was abnormal with an increment of end-systolic volume, while in the controls LVEF increased significantly during stress. Seven of the eight patients with an abnormal ejection fraction response had constant T1-201 perfusion defects. This study indicates that latent left ventricular dysfunction is present in patients with prior myocarditis and that nuclear study is useful for long-term follow-up.

Adult↗
PubMed1985

Thyroid-stimulating antibody bioassay using porcine thyroid cells cultured in follicles.

Isolated porcine thyroid cells were cultured in agarose-coated dishes and allowed to reform follicles with normal polarity. The thyroid cells reaggregated into follicles were compared with cells cultured in monolayer for cAMP responsiveness to TSH and thyroid-stimulating antibody (TSAb). The cells in follicles were sensitive to TSH stimulation and responded to the hormone at concentrations as low as 3.3-10 microU/ml with an increase in cAMP production. In contrast, 10-50 microU/ml TSH were required to elicit a cAMP response in cells cultured in monolayer using identical conditions. cAMP responsiveness to TSAb also was greater in the cells organized into follicles. TSAb was detected in serum from 89.4% of 66 untreated patients with hyperthyroid Graves' disease using thyroid follicles, but TSAb was detected in serum from only 60% of the patients when assayed using cells in monolayer. The assay using thyroid follicles was used to measure TSAb in 27 euthyroid patients who were euthyroid while receiving thionamide therapy and compared with 20-min thyroid 131I uptake after T3 suppression. TSAb was present in 11 of 12 nonsuppressible patients and in 5 of 15 suppressible patients. TSAb was positively correlated with 20-min 131I thyroid uptake. We conclude that thyroid cells cultured in follicles are suitable for measuring TSAb.

Adolescent↗
PubMed1985

[Digital perfusion images for evaluating patients with mitral valve replacement].

To determine whether the distribution of pulmonary perfusion can be applied as a noninvasive means of evaluating patients with mitral valve replacement (MVR), computerized Tc-99m MAA pulmonary perfusion images (digital perfusion images: DPI) were obtained for 32 patients in the preoperative, early postoperative and late postoperative (18 months mean) periods. DPI consisted of isocount areas, and a 100-70% area was defined as a hyperperfusion area. The distribution of pulmonary perfusion was evaluated using patterns of hyperperfusion area in anterior DPI. In 32 patients above-mentioned had the hyperperfusion areas in the upper lung fields preoperatively, the perfusion of the lung base was investigated. In 21 patients hyperperfusion area appeared in the lung base in the late follow-up period (group A), and all patients improved clinically. In 11 patients, the DPI improved to nearly normal patterns. In five patients, the DPI improved after one year postoperatively. In 11 patients, hyperperfusion areas did not appear in the lung base in the late follow-up period (group B). Six of the 11 patients did not improve clinically. There were no significant hemodynamic differences between groups A and B except for slight differences in the postoperative pulmonary vascular resistance. These results suggested significant correlations between the clinical improvement and the normalization of the DPI. The use of DPI patterns may facilitate quantitative and objective estimations of postoperative states. Since DPI are easy to perform noninvasively, DPI may comprise a useful graphic diagnostic method for evaluating patients with MVR.

Adolescent↗