• Journal of Cardiovascular Imaging
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• v.31 no.1
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• pp.39-40
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• 2023

• Journal of Cardiovascular Imaging
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• v.31 no.4
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• pp.188-190
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• 2023

• Journal of Cardiovascular Imaging
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• v.31 no.1
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• pp.62-64
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• 2023

• Journal of Cardiovascular Imaging
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• v.31 no.1
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• pp.68-70
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• 2023

• Proceedings of the Korean Society of Medical Physics Conference
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• 2003.09a
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• pp.49-49
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• 2003

목적 : 심초음파는 비침습적이므로 반복적으로 정확히 심질환의 경과를 관찰하여 치료효과 및 수술시기를 정할 수 있는 검사로서 임상적으로 매우 유용하다. 실시간 심근조영심초음파에 의한 time intensity 평가는 부위별로 수행됨으로 연속적으로 위치하는 관심영역이 intensity에 있어 심장의 움직임 변화에 영향을 받는다. Time intensity 곡선의 최적의 곡선맞춤을 위해 주기적인 심장 운동 매개변수를 조합해 기존의 모델을 보정한 안정적인 측정방법을 제시한다. 방법 : 심장의 운동에 의한 특징적인 정보를 설명하기 위해 기존의 문헌에 제시된 지수 함수에 주어진 심박수로 만들어진 시간에 관한 일반적인 정형파 함수를 추가한다. C(t) = A[1 - exp($\beta$t)] + Dsine(2$\pi$ft + $\theta$) C(t): videointensity A: plateau videointensity (blood volume) $\beta$: capillary blood velocity (rate constant of rise in videointensity) t: pulsing interval (ms) D: displacement from the periodic variance of the curve (estimated motion field from the ejection point for the ratio between systole and diastole) f: heart rate $\theta$: transit time issue A $\times$ $\beta$ : myocardial blood flow 관상동맥의 관류 데이터에 대한 실험이 펄스간격에 대한 비디오 세기로 수행되었다. 그리고 이러한 결과들이 the sum of squares due to error, R square, root mean squared error로 평가되었다. 결과 : 실험결과, 주기적인 심장의 움직임과 심박출 시점으로부터의 변위를 잘 기술하고 곡선에서의 측정 점들이 예측된 심장 움직임에 따라 성공적으로 표시되었다. 뿐만 아니라 보정된 모델이 현저한 적합도의 향상을 보여주었다. 결론 : 제시된 접근방법은 각각의 측정에서 심장 운동 영역의 변화에 독립적이며 측정 시점에 의해 영향받지 않고 심근 관류의 안정적인 측정이 가능하다. 심장의 움직임에 관한 매개변수를 조합한 모델로 곡선접합을 수행함으로써 관류의 정량적 정보를 좀더 정확하게 얻을 수 있으며 임상적 이용을 가능하게 할 것으로 기대된다.

• Journal of Chest Surgery
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• v.35 no.9
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• pp.672-674
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• 2002

A 40-years-old male with dilated cardiomyopathy(DCMP) and end-stage heart failure had undergone partial left ventriculectomy(PLV) in July 1997 and then underwent cardiac transplantation in January 1999. Three months later he showed increased ejection fraction (EF) from 26% to 42.6%, decreased left ventricular end diastolic diameter(LVEDD) from 71mm to 45mm, cardiac output(CO) 3.95 L/min and cardiac index(CI) 2.28 L/min/m$^2$echocardiographically. Eight months later, left ventriclular end diastolic and systolic diameters increased to 56 and 51 mm respectively and EF decreased to 17% in echocardiographic follow-up. He had been on maximum medication until he underwent cardiac transplantation 18 months after the PLV. Consecutive myocardial biopsies (1, 3 and 6 month later) showed ISHLT (international society of heart and lung transplantation) class la and the treatment for rejection was not needed until now on. We report a partial left ventriculectomy as a successful bridge to cardiac transplantation in a patient with DCMP and end-stage heart failure.

• Clinical and Experimental Pediatrics
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• v.46 no.5
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• pp.484-489
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• 2003

Purpose : To understand morphologic and hemodynamic variations in patients with pulmonary atresia with intact ventricular septum(PA/IVS), and to decide the best treatment modalities, we measured right ventricular volume, inflow, and outflow valvular annulus size in these patients and compared them with those of normal newborns. Methods : Eight patients with PA/IVS diagnosed by echocardiography from January to December 2001 were enrolled in this study. Among the total eight patients, five were male and three were female. The mean age of patients was 6.9 days(1-34 days), and the mean body weight was 3,343 gm (2,970-4,000 gm). Ten fullterm newborn infants with sepsis or hyperbilirubinemia without heart disease were enrolled as a control group. Echocardiographic and Doppler studies using Acuson Aspen (7Mh probe) were recorded on super-VHS videotape and later on, with review mode. We measured volumes of right and left ventricles, aortic, pulmonic, mitral and tricuspid valvular annulus sizes using an installed program, and then these parameters were compared with those of the control group. Results : Mean Z-value of tricuspid valvular annulus in PA/IVS was $-3.69{\pm}2.80$(-8.4--0.45), and tricuspid/mitral valvular annulus size ratio $0.68{\pm}0.15$(0.43--0.84). The more the tricuspid/mitral valvular annulus size ratio, the more Z-value of tricuspid valvular annulus(P=0.003, r=0.885). Those patients who underwent pulmonary valvuloplasty(balloon or surgical) had a tendency toward larger volume of the right ventricle, more Z-value of pulmonic and tricuspid valvular annulus, and more tricuspid/mitral valvular annulus size ratio than those patients who underwent a shunt operation. Conclusion : Compared to a measurement of the volume of the right ventricle, measurements of tricuspid/mitral valvular annulus size ratio and Z-value of tricuspid valvular annulus may be easier and better parameters to decide the treatment method and to predict prognosis in PA/IVS patients.

• Clinical and Experimental Pediatrics
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• v.45 no.9
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• pp.1097-1105
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• 2002

Purpose : This study was conducted to estabilish the prevalence, clinical features and relationship between ECG findings and echocardiographic findings of Wolff-Parkinsion-White(WPW) syndrome in asymptomatic preschool children. Methods : An electrocardiographic screening study was performed on 77,824 preschool children in Jeonbuk province from April, 1999 to August, 2001. Patients with WPW syndrome underwent echocardiographic study. Results : Twenty three patients with WPW syndrome were discovered by electrocardiographic screening of preschool children. The prevalence rate was 2.9 per 10,000 preschool children and there was no significant sexual difference. Two patients had a history of symptoms related to tachyarrythmia. According to the ECG classification of Rosenbaum et al., five patients were type A and 18 were type B. Utilizing the criteria of Gallagher et al, right anterior, 12 patients; right anteiror paraseptal, four patients; left anteiror, three patients. Nineteen of 23 patients underwent echocardiographic study. Four of five patients with type A WPW syndrome had abnormal early systolic anterior motion of left ventricular posterior wall. Twelve of 14 patients with type B had abnormal interventricular septal motion characterized by early sytolic posterior motion immediately after inscription of the delta wave. Conclusion : The prevalence rate of preschool children in Jeonbuk province was 2.9/10,000. By the classification according to the electrocardiographic findings, the accessory pathway location was dominant right side than left side. In the echocardiographic study, type A WPW syndrome showed abnormal left ventricular posterior wall motion and type B WPW showed abnormal interventricular septal motion.

• Clinical and Experimental Pediatrics
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• v.45 no.5
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• pp.609-614
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• 2002

Purpose : The purpose of our investigation was to explore the natural course, and the factors that influence the natural course, in ostium secundum atrial septal defect(ASD) diagnosed within the first 4 weeks of life. Methods : We studied patients with ASD diagnosed within the first 4 weeks of life during the period from September 1995 to September 1999 in our hospital. The diagnosis and measuring of the size of ASD was carried out by two-dimensional echocardiogram(2DE, Hewlett-Packard Sonos $2500^{(R)}$) from subcostal long and short axis views. Results : There were 61 patients - 29 males and 32 females. According to the size of their defects, we divided them into four groups; group A(less than 4 mm : 24 cases), group B(four mm-six mm : 27 cases), group C(six mm-eight mm : six cases), group D(more than eight mm : four cases). In groups A and B, 22 of 24 patients(91.7%) and 23 of 27 patients(85.2%) had each closed spontaneously. In group C, four of six patients had closed spontaneously. In group D, no patient had closed spontaneously and three of four patients had been closed surgically. There were significant differences in the rate of spontaneous closure between less than six mm group and more than six mm group in the size of the defect(P<0.05). There were no significant differences in the rate of spontaneous closure between ASD combined with simple cardiac defect and isolated secundum ASD. Conclusion : We conclude that defects smaller than six mm in diameter are very likely to close spontaneously.

• Journal of Biomedical Engineering Research
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• v.19 no.6
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• pp.571-575
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• 1998

One of the most significant features of diagnostic ultrasonic instruments is to provide real time information of the soft tissues movements. Echocardiogram has been widely used for diagnosis of heart diseases since it is able to show real time images of heart valves and walls. However, the currently used ultrasonic images are deteriorated due to presence of speckle noises and image dropout. Therefore, it is very important to develop a new technique which can enhance ultrasonic images. In this study, a technique which extracts enhanced binary images in echocardiograms was proposed. For this purpose, a digital moving image file was made from analog echocardiogram, then it was stored as 8-bit gray-level for each frame. For an efficient image processing, the region containing the heat septum and tricuspid valve was selected as the region of interest(ROI). Image enhancement filters and morphology filters were used to reduce speckle noises in the images. The proposed procedure in this paper resulted in binary images with enhanced contour compared to those form the conventional threshold technique and original image processing technique which can be further implemented for the quantitative analysis of the left ventricular wall motion in echocardiogram by easy detection of the heart wall contours.