• The Korean Journal of Nuclear Medicine
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• v.20 no.1
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• pp.85-91
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• 1986

In detecting, localizing and quantitating cardiac shunts, radionulide angiocardiography has been known to be a simple and safe method compared with oxymetry method. To ascertain the availability of the results obtained by radionuclide angiocardiography for the evaluation of patients with cardiac shunt, author compared the Qp/Qs ratios(pulmonary to systemic flow ratios) obtained by radionuclide angiocardiography with the results of oximetry method in 40 patients with left to right shunt, and also compared the results of radionuclide angiocardiography examined before and after shunt operation in 8 patients. The results were as follows: 1) Of the 161 patients examined radionuclide angiocardiography, 98 were thought to have cardiac shunts: right to left shunt id 27, left to right shunt in 71. Of the 71 patients who had left to right shunt, 40 who were examined with both radionuclide angiocardiography and oxymetry had following congenital heart disease: VSD in 21, ASD in 9 and PDA in 10. 2) Comparison of Qp/Qs ratios obtained during radionuclide angiocardiography and oxymetry revealed good correlation (linear regression analysis yielded correlation coefficient of 0.80) in 32 patients whose Qp/Qs ratio obtained during oxymetry were below 3.0, but very poor correlation in 8 patients whose Qp/Qs ratios were above 3.0 3) Radionuclide angiocardiography is a relatively safe and simple method in postoperative evaluation of patients with cardiac shunt.

• The Korean Journal of Nuclear Medicine
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• v.20 no.2
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• pp.47-52
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• 1986

A noninvasive procedure for diagnosis and quantitation of right-to-left intracardiac shunts will enhance the management of patients with cyanotic congenital heart disease. This study describes an application of radionuclide (RN) angiocardiography for quantitation of right-to-left shunt amount. Gamma variate model was fitted to radionuclide data recorded over the carotid artery. Data analysis was performed retrospectively in 35 patients who underwent cardiac catheterization within a week from the day of RN angiocardiography. Thirty one of the patient had right-to-left shunts and 4 of them had left-to-right shunts. Both the radionuclide and Fick measurements correlated well (r=0.93, 0.93, 0.89, p<0.01 in each measurements). Therefore, RN angiocardiography data may be used for accurate calculation of right-to-left shunts in cyanotic congenital heart disease patients.

• The Korean Journal of Nuclear Medicine
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• v.18 no.2
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• pp.31-38
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• 1984

• Nuclear Medicine and Molecular Imaging
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• v.40 no.4
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• pp.200-204
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• 2006

Purpose: Determination of pulmonary to systemic blood flow ratio (QP/QS) is important for the management of patients with left-to-right shunt. This study was performed to assess the agreement of Qp/Qs ratio using the radionuclide method and oxymetry, to investigate the factors influencing the agreement, and to know how interchangeable the results of each technique. Materials and Methods: We compared the Qp/Qs measured by single-pass radionuclide angiocardiography and oxymetry during catheterization in 207 patients who underwent both studies. In radionuclide method, Qp/Qs was calculated from the pulmonary time-activity curves using a gamma variate fit. The correlation and Bland-Altman analysis were performed according to the levels of shunt and associated lesions. Results: The mean Qp/Qs was $1.83{\pm}0.50$ by radionuclide, and $1.74{\pm}0.51$ by oxymetry. The overall correlation coefficient was 0.86(p<0.001), and Bland-Altman range of agreement encompassing 4SD was 1.05. For atrial septal defect, ventricular septal defect, patent ductus arteriosus, tricuspid and mitral insufficiency, the correlation coefficient was 0.78, 0.90, 0.84, 0.63 and 0.44, and Bland-Altman range was 1.51, 0.74, 0.96, 1.57, and 1.50, respectively. Conclusion: There is good agreement but wide variance between the Qp/Qs ratios by radionuclide method and oxymetry. Associated atrioventricular valvar insufficiency decreases the correlation coefficient and widens the variance. Wide overall variance suggests that Qp/Qs measurements by two techniques should not be used interchangeably.

• The Korean Journal of Nuclear Medicine
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• v.21 no.2
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• pp.155-165
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• 1987

The noninvasive nature of the radionuclide angiocardiography provided a useful approach for the evaluation of left-to-right cardiac shunts (LRCS). While the qualitative information can be obtained by inspection of serial radionuclide angiocardiograms, the quantitative information of radionuclide angiocardiography can be obtained by the analysis-of time-activity curves using advanced computer system. The count ratios method and pulmonary-to-systemic flow ratio (QP/QS) by gamma variate fit method were used to evaluate the accuracy of detection and localization of LRCS. One hundred and ten time-activity curves were analyzed. There were 46 LRCS (atrial septal defects 11, ventricular septal defects 22, patent ductus arteriosus 13) and 64 normal subjects. By computer analysis of time-activity curves of the right atrium, ventricle and the lungs separately, the count ratios modified by adding the mean cardiac transit time were calculated in each anatomic site. In normal subjects the mean count ratios in the right atrium, ventricle and lungs were 0.24 on average. In atrial septal defects, the count ratios were high in the right atrium, ventricle and lungs, whereas in ventricular septal defects the count ratios were higher only in the right ventricle and lungs. Patent ductus arteriosus showed normal count ratios in the heart but high count ratios were obtained in the lungs. Thus, this count ratios method could be separated normal from those with intra cardiac or extracardiac shunts, and moreover, with this method the localization of the shunt level was possible in LRCS. Another method that could differentiate the intracardiac shunts from extracardiac shunts was measuring QP/QS in the left and right lungs. In patent ductus arteriosus, the left lung QP/QS was higher than those of the right lung, whereas in atrial septal defects and ventricular septal defects QP/QS ratios were equal in both lungs. From this study, it was found that by measuring QP/QS separately in the lungs, intracardiac shunt could be differenciated from extracardiac shunts.

• The Korean Journal of Nuclear Medicine
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• v.25 no.2
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• pp.186-191
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• 1991

Radionuclide cardiac studies lend themselves exceptionally well to functional imaging. This is especially true for gated blood pool scan (GBP). Making functional images is also possible in radionuclide angiocardiography (RNAC). In this study we tried to validate the functional images obtained from RNAC by comparing it with GBP. Twenty three patients (16 patients with coronary artery diseases, 5 with hypertensive heart diseases, and 2 with nonspecific chest pains) underwent simultaneous RNAC and GBP at the same position (LAO $45^{\circ}$). From both studies, global ejection fraction, regional ejection fraction, phase image, amplitude image, stroke image, paradox image, maximum ejection and maximum filling rates were obtained. Global ejection fraction are almost same in both studies. Regional ejection fractions of apex and inferior portion of left ventricle calculated from RNAC are well correlated with those of GBP. Phase and paradox image, maximum ejection and maximum filling rates were obtained. Global ejection fraction are almost same in both studies. Regional ejection fractions of apex and inferior portion of left ventricle calculated from RNAC are well correlated with those of GBP. Phase and paradox images of RNAC are very similar to those of GBP. However, amplitude and stroke images are different. Regional ejection fractions of the left ventricular base, maximum ejection and maximum filling rates obtained from RNAC are significantly different from those of GBP. In conclusion, albeit all of functional images of RNAC is not same as GBP, regional walt motions and global left ventricular function are expected to be successfully analyzed by phase and paradox image and ejection fraction.

• Journal of Chest Surgery
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• v.15 no.2
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• pp.194-203
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• 1982

In this investigation we undertook to evaluate the utility of radionuclide cardiac angiography in the detection of cardiac shunts before and after surgical correction. Time-activity curves of ventricles and lungs were evaluated after bolus intravenous injection of 99mTc-human serum albumin in 512 preoperative patients and 551 post-operative patients. Omitting 31 cases of technical failure due to poor bolus, we detected shunts in 459 cases of 481 preoperative evaluations, so the detectability was 95.4%. The cases which couldn`t be detected by this method had small amount of shunt. Also the degree of shunt detected by radioisotope methods were well correlated with oxymetry method. [r=0.89, p<0.01 ] In postoperative evaluations, 18 out of 411 patients with left to right shunt and 10 out of 140 right to left shunt were found to have remnant shunts with radionuclide cardiac angiography. Of the 28 cases with failed operation, 2 were confirmed in reoperation, 2 by cardiac catheterization, 2 by two -dimensional echocardiography. All except one .f these patients had membranous ventricular septal defects and those with left to right shunts had moderate to severe pulmonary hypertension and shunt amount. Also those had larger septal defects than control group. We consider that radionuclide cardiac angiography is a simple and noninvasive method which can show the preoperative diagnosis and postoperative follow up of cardiac shunts.

• The Korean Journal of Nuclear Medicine
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• v.18 no.1
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• pp.9-17
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• 1984

The purpose of this study is to investigate significance of new method for quantification of left to right cardiac shunts using deconvolution analysis as an adjunct to gamma variate analysis in patients with bad bolus injection. In the present study, quantitative radionuclide angiocardiography (QRAC) was performed with and without deconvolution analysis (DA) in 37 patients with left to right shunt and 103 control patients without shunt. The results obtained were as follows; 1) The mean value of $Q_p/Q_s$ in 103 control patients was $1.10{\pm}0.12$ without DA, and was $1.01{\pm}0.03$ with DA. 2) Correlation(r) between oximetry and QRAC with DA was 0.87 and correlation(r) between oximetry and QRAC without DA was 0.61. 3) The 13 patients with left to right shunt, whose $Q_p/Q_s$ was greater than 3.0 by QRAC without DA, was studied by DA. Then the $Q_p/Q_s$ values were measurable in these 13 patients by DA and they showed significant correlation with oximetry. (r=0.68) The results indicate that deconvolution analysis technique for quantification of a left to right shunt provides more reliable and accurate shunt quantification, and reduces the influences of poor bolus injection.