• 핵의학기술
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• 제22권2호
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• pp.92-96
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• 2018

핵의학 간담도 검사 시, 담낭의 수축력을 정량적으로 평가하기 위하여 지방식(fatty meal)을 이용한 전면상에서의 담낭박출률(gallbladder ejection fraction ; GB EF%)을 진단에 이용하고 있다. 하지만, 담낭과 다른 구조물이 전면상에서 겹쳐질 경우, 담낭 박출률 평가가 정확히 이루어지지 않는다. 이러한 오차를 줄이기 위해 본 연구에서는 전면상과 우측 측면상에서 계산한 GBEF%의 유의한 차이가 있는 지 알아보고자 한다. 본원에 내원한 임의의 환자 50명을 대상으로 $^{99m}Tc$-Mebrofenin 370 MBq를 정맥주사 후 간담도 검사를 실행하였다. 검사는 SKYLIGHT(Philips, United States)을 이용하여 10분, 20분, 30분, 60분, 그리고 지방식(치즈와 우유)을 시행하고 30분 후에 90분 째, 전면상과 우측 측면 영상을 획득하였다. JETstream workspace 프로그램에서 60분째와 90분째 전면상과 우측 측면상에서 GBEF%을 구하였다. 보다 정확한 관심영역 설정을 위해 CT영상을 참고하였고, 4명의 방사선사가 동일한 영상에서의 GBEF%을 구하여 평균값을 계산하였다. 통계분석프로그램SPSS version23(SPSS Inc. USA)을 이용하여 전면상과 우측 측면상에서 GBEF%의 차이에 유의한 차이가 있는지 평가하였다. 무작위 50명 환자의 전면상에서 GBEF%의 평균값은 63.2고, 우측 측면상에서 GBEF%의 평균값은 62.7으로 전면상 대비 우측 측면상에서 0.5% 감소하였다. 전면상과 우측 측면상에서 GBEF%의 대응표본 t-검정 결과 P>0.05으로 유의한 차이가 없었다. 이를 통해 전면상에서 담낭과 다른 구조물이 분리되지 않아 담낭박출률의 오차가 발생하는 경우, 우측 측면상을 이용하여 GBEF%을계산하면 보다 더 정확한 담낭박출률이 평가되는 것으로 사료된다.

• 대한핵의학회지
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• 제25권1호
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• pp.53-60
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• 1991

Extracorporeal shock wave lithotripsy (ESWL) with adjunctive oral litholytic therapy has proven to be a useful treatment in selected patients with gallbladder stones. To study the effect of ESWL on gallbladder dynamics, $^{99m}Tc-DISIDA$ hepatobiliary scintigraphy was done for 25 patients with symptomatic gallstones and 10 normal controls. Of these 25 patients, 15 were treated with ESWL and adjunctive oral litholytic agents (ESWL group) and 10 were treated only with oral litholytic agents (UDCA group). After overnight fast and gallbladder visualization on a routine hepatobiliary scintigraphy with 7mCi of $^{99m}Tc-DISIDA$, subjects were given fatty meal and imaged with a gamma camera interfaced to a computer (1 frame/minute for 70 minutes). A gallbladder time-activity curve was generated and latent period (LP), ejection period (EP), ejection fraction (EF) and ejection rate (ER) were calculated. ESWL group were studied before, 1day after and 2weeks after ESWL, and WDCA group were studied before and 2weeks after starting oral medication. Mean basal EF was significantly reduced in patients but other parameters were not reduced. In ESWL group, mean EF and mean ER at lday after ESWL were reduced. In 3 of them, gallbladder was not visualized at all. Two weeks after ESWL, however, all parameters were recoverd to basal level. In UDCA group, all parameters were not changed significantly during medication. We can conclude that ESWL has such immediate adverse effect on gallbladder dynamics as reducing contractility and nonvisualization of gallbladder but it has no long-term effect.

• 설비공학논문집
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• 제13권10호
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• pp.1009-1016
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• 2001

The heat transfer enhancement by pulsatile flow in a triangular grooved channel has been experimentally investigated in this study The experiment was performed in the ranges of the Reynolds number from 270 to 910, the pulsatile fraction from 0.125 to 0.75, and the Strouhal number from 0.084 to 0.665. It was measured that the heat transfer improves up to 350% compared with the steady flow case at Re=270,$\eta=0.5$, and St=0.335. The heat transfer enhancement was found to increase as the pulsatile fraction increases and the Reynolds number decreases. It was also found that the heat transfer enhancement is maximized at a specific pulsatile frequency satisfying the resonant condition. The nondimensional frequency, i.e., the Strouhal number at the resonant condition was found to increase as the Reynolds number decreases. The flow visualization revealed that the heat transfer enhancement results from the strong mixing caused by the repeating sequence of vortex formation, rotation and subsequent ejection from the grooves by the pulsatile flow.

• Journal of Chest Surgery
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• 제33권10호
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• pp.777-784
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• 2000

Congenital aortic stenosis in children is characterized by "excessive" left ventricular hypertrophy with reduced left ventricular systolic wall stress that allows for supernormal ejection performance. We hypothesized that left ventricular wall stress was decreased immediately after surgical correction of pure congenital aortic stenosis. Also measuring postoperative left ventricular wall stress was a useful noninvasive measurement that allowed direct assessment for oxygen consumption of myocardium than measuring the peak systolic pressure gradient between ascending aorta and left ventricle for the assessment of surgical results. Material and Method: Between September 1993 and August 1999, 8 patients with isolated congenital aortic stenosis who underwent surgical correction at Yonsei cardiovascular center were evaluated. There were 6 male and 2 female patients ranging in age from 2 to 11 years(mean age, 10 years). Combined Hemodynamic-Ultrasonic method was used for studying left ventricular wall stress. We compared the wall stress peak systolic pressure gradient and ejection fraction preoperatively and postoperatively. Result: After surgical correction peak aortic gradient fell from 58.4${\pm}$17.6, to 23.7${\pm}$17.7 mmHg(p=0.018) and left ventricular ejection fraction decreased but it is not statistically significant. In the consideration of some factors that influence left ventricular end-systolic wall stress excluding one patient who underwent reoperation for restenosis of left ventricular outflow tract left ventricular end-systolic pressure and left ventricular end-systolic dimension were fell from 170.6${\pm}$24.3 to 143.7${\pm}$27.1 mmHg and from 1.78${\pm}$0.4 to 1.76${\pm}$0.4 cm respectively and left ventricular posterior wall thickness was increased from 1.10${\pm}$0.2, to 1.27${\pm}$0.3cm but it was not statistically singificant whereas left ventricular end-systolic wall stress fell from 79.2${\pm}$24.9 to 57.1${\pm}$27.6 kdynes/cm2(p=0.018) in 7 patients. For one patient who underwent reoperation peak aortic gradient fell from 83.0 to 59.7 mmHg whereas left ventricular end-systolic wall stress increased from 67.2 to 97.0 kdynes/cm2 The intervals did not change significnatly. Conclusion ; We believe that probably some factors that are related to left ventricular geometry influenced the decreased left ventricular wall stress immediately after surgical correction of isolated congenital aortic stenosis. Left ventricular wall stress is a noninvasive measurement and can allow for more direct assesment than measuring peak aortic gradient particularly in consideration of the stress and oxygen consumption of the myocardium therefore we can conclude it is a useful measurement for postoperative assessment of congenital aortic stenosis.

• Journal of Chest Surgery
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• 제33권10호
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• pp.785-791
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• 2000

Left ventricular dysfuction is common in immediate postoperative periods after surgical correction of heart diseases with chronic left ventricular volume overload. We speculated postoperative changes of left ventricular volume and unction in patients with patent ductus osus(PDA) who had underwent surgical repair at ages older than 16 years. Factors influencing postoperative left ventricular volume and function were also analyzed. Material and Method: From August 1989 to August 1999 thirty-siz adult patients with PDA 28 females and 8 males. were enrolled in this study. Their age ranged from 16 years to 57 years(mean :32 years). Types of surgical repair were division with primary closure in 22, division with patch closure in 6, internal obliteration using cardiopulmonary bypass in 4 and ligation in 4. Aortic clamping was combined during surgical repair in 22(61%) and cardiopulmonary bypass was used in 8(22%) Two-dimensional echocardiography studies were performed in 34(94%) preoperatively and in 25(66%) immediate postoperatively to assess postoperative changes of left ventricular internal dimensions. left ventricular volume and ejection fraction. Duration of postoperative follow-up ranged from 1 month to 99 months (mean:22 months) and 10 patients underwent 16 echocardiographic evaluation during this period Result : Preoperative and postoperative left ventricular systolic dimensions(LVIDs) were 42$\pm$8.0mm and 42$\pm$8.3mm left ventricular diastolic dimensions(LVIDd) were 64$\pm$10.0mm and 56$\pm$7.4mm left ventricular end systolic volumes(LVESV) were 62$\pm$19cc (z=1.87$\pm$0.06) and 59$\pm$24cc(z=1.78$\pm$0.08) left ventricular end diastolic volumes(LVEDL) were 169$\pm$40cc(z-1.17$\pm$0.1) and 112$\pm$29cc(z=0.85$\pm$0.1) and ejection fractions(EF) were 66$\pm$6.7% and 48$\pm$12.6% respectively. There were statistically significant differences between preoperative and postoperative values in LVDIDd(p=0.001) LVEDV(p=0.001) and EF(p=0.0001) while no significant difference is LVIDs and LVESV. Postoperative depression of ejcection fraction was significantly related with z-score of preoperative LVESV and LVEDV by univariateanalysis while LVEDV only was significant risk factor for postoperative LV dysfunction by multiple regressioin analysis ($\Delta$LVEF=-13.3-4.62$\times$LVEDV(z), p=0.001) During the follow-up periods ejection fractions become normalized in all except one patients. Conclusion ; Left ventricular function is usually deteriorated after the surgical correction of PDA in adult age and preoperative LVEDV is a major determinant of postoperative LV function.

• 대한핵의학회지
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• 제32권5호
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• pp.403-413
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• 1998

목적: 좌심실의 부피와 구혈률을 Cedars 소프트웨어로 구하였을 때 정량한 값과 심근벽운동과 심근의 수축기 두꺼워짐을 등급으로 평가한 방법의 재현성을 알아보고자 하였다. 대상 및 방법: 33명의 무작위 추출된 환자를 상대로 통상의 이중동위원소 휴식/부하 심근관류 SPECT 때 부하 Tc-99m-MIBI 게이트 SPECT를 촬영한 후 이어서 같은 자리에서 게이트 SPECT를 한번 더 촬영하였다. 재구성한 후 Cedars 소프트웨어로 확장기말 부피와 수축기말 부피, 구혈률을 측정하여 연속 측정의 재현성을 평균변이계수와 Bland Altman 도표를 그려 분석하였다. 벽운동을 5등급으로 점수를 매겨 연속촬영한 영상의 판독 재현성을 조사하였다. 심근벽의 수축기 두꺼워짐을 역시 4등급으로 점수를 매겨 판독 재현성을 조사하였다. 결과: 확장기말 부피와 수축기말부피는 평균변이계수가 5.0 ml, 3.9 ml이고 구혈률의 평균변이계수는 1.9%이었다. 2표준편차 범위는 확장기말 부피는 18 ml, 수축기말부피는 17 ml이었다. 심근벽운동과 심근의 수축기 두꺼워짐은 kappa 값이 0.7로 판독재현성이 우수하였다. 결론: 이 연구의 결과로 같은 환자를 같은 위치에서 두 번 연이어 게이트 심근 Tc-99m-MIBI SPECT를 촬영할 때, 우리가 산출한 변이가 우수하고 약물효과를 판정할 때 기준으로 삼을 오차범위를 어느 정도로 정해야 하는지 확립하였다.

• 대한의용생체공학회:의공학회지
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• 제36권5호
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• pp.198-203
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• 2015

The purpose of the study is to examine the effects of pacemaker location on cardiac pumping efficacy theoretically. We used a three-dimensional finite element cardiac electromechanical model of canine ventricles with models of the circulatory system. Electrical activation time for normal sinus rhythm and artificial pacing in apex, left ventricular free wall, and right ventricular free wall were obtained from electrophysiological model. We applied the electrical activation time maps to the mechanical contraction model and obtained cardiac mechanical responses such as myocardial contractile ATP consumption, stroke work, stroke volume, ejection fraction, and etc. Among three artificial pacing methods, left ventricle pacing showed best performance in ventricular pumping efficacy.

• 중환자간호학회지
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• 제4권1호
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• pp.1-10
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• 2011

Purpose: The study was conducted to find out clinical characteristics for coronary artery disease patients with diabetes mellitus. Methods: We retrospectively reviewed the electronic medical records which included the data of 6,792 patients, who had been diagnosed coronary artery disease (CAD) such as angina or acute myocardial infarction and admitted to a university hospital in Seoul from January, 2005 to November, 2010. Results: Of the 6,792 patients, 43% had been diagnosed diabetes as comorbidity. The CAD patients with diabetes had lower left ventricular ejection fraction, stayed longer at hospital, and spent on more time from the first symptom to hospital visit than those without diabetes. In addition, they were more likely to have multi vessel coronary artery disease. Conclusion: The CAD patients with diabetes lay on the various factors which can make more worsen condition. Hence, we need to pay attention to specialized nursing care and patient education for the CAD patients with diabetes.

• 대한핵의학회지
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• 제32권1호
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• pp.1-9
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• 1998

Gated myocardial SPECT and attenuation correction gave birth to new insights into the pathophysiology of ischemic myocardial perfusion and function in clinical routine practice. Gated myocardial Tc-99m-compound SPECT improved diagnostic accuracy of coronary artery disease and enabled us to observe motion and thickening of myocardial walls as well as myocardial perfusion at the same time. Quantitative and qualitative assessment of myocardial performance and perfusion let us to understand the myocardial physiology in ischemia and infarction. In every patient who underwent gated perfusion SPECT, we will find ejection fraction, left ventricular volumes and regional wall motion. There are hopes to use gated TI-201 SPECT for the same purpose and to use gated SPECT for evaluation of wall motion and thickening at stress or immediate post-stress. Attenuation correction could improve diagnostic accuracy mainly by increasing normalcy ratio or performance of non-expert physicians. Both gated methods and attenuation correction improved specificity of non-expert physicians in diagnosing patients with moderate pretest likelihood. New imaging techniques will fill the desire of cardiologists to examine function and perfusion, and possibly metabolism in their clinical routine practice.

• Journal of Chest Surgery
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• 제49권4호
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• pp.292-294
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• 2016

Cardiac resynchronization therapy (CRT) is a new treatment for refractory heart failure. However, most patients with heart failure treated with CRT are adults, middle-aged or older with idiopathic or ischemic dilated cardiomyopathy. We treated a 12-year-old boy, who was transferred after cardiac arrest, with dilated cardiomyopathy, left bundle-branch block, and ventricular tachycardia. We performed cardiac resynchronization therapy with a defibrillator (CRT-D). After CRT-D, left ventricular ejection fraction improved from 22% to 4 4% assessed by echocardiogram 1 year postoperatively. On electrocardiogram, QRS duration was shortened from 206 to 144 ms. The patient's clinical symptoms also improved. For pediatric patients with refractory heart failure and ventricular arrhythmia, CRT-D could be indicated as an effective therapeutic option.