• Korean Journal of Radiology
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• 제1권2호
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• pp.91-97
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• 2000

Objective: To determine whether the time-intensity curves acquired by test and main dose contrast injections for MR angiography are similar. Materials and Methods: In 11 patients, repeated contrast-enhanced 2D-turbo-FLASH scans with 1-sec interval were obtained. Both test and main dose timeintensity curves were acquired from the abdominal aorta, and the parameters of time-intensity curves for the test and main boluses were compared. The parameters used were arterial and venous enhancement times, arterial peak enhancement time, arteriovenous circulation time, enhancement duration and enhancement expansion ratio. Results: Between the main and test boluses, arterial and venous enhancement times and arteriovenous circulation time showed statistically significant correlation (p < 0.01), with correlation coefficients of 0.95, 0.92 and 0.98 respectively. Although the enhancement duration was definitely greater than infusion time, reasonable measurement of the end enhancement point in the main bolus was impossible. Conclusion: Only arterial and venous enhancement times and arteriovenous circulation time of the main bolus could be predicted from the test-bolus results. The use of these reliable parameters would lead to improvements in the scan timing method for MR angiography.

• 대한자기공명의과학회:학술대회논문집
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• 대한자기공명의과학회 1998년도 제3차 추계학술대회 초록집
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• pp.114-118
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• 1998

• Korean Journal of Radiology
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• 제2권3호
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• pp.121-131
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• 2001

Echocardiography and catheterization angiography suffer certain limitations in the evaluation of congenital heart diseases in adults, though these are overcome by MRI, in which a wide field-of view, unlimited multiplanar imaging capability and three-dimensional contrast-enhanced MR angiography techniques are used. In adults, recently introduced fast imaging techniques provide cardiac MR images of sufficient quality and with less artifacts. Ventricular volume, ejection fraction, and vascular flow measurements, including pressure gradients and pulmonary-to-systemic flow ratio, can be calculated or obtained using fast cine MRI, phase-contrast MR flow-velocity mapping, and semiautomatic analysis software. MRI is superior to echocardiography in diagnosing partial anomalous pulmonary venous connection, unroofed coronary sinus, anomalies of the pulmonary arteries, aorta and systemic veins, complex heart diseases, and postsurgical sequelae. Biventricular function is reliably evaluated with cine MRI after repair of tetralogy of Fallot, and Senning's and Mustard's operations. MRI has an important and growing role in the morphologic and functional assessment of congenital heart diseases in adolescents and adults.

• Journal of Oral Medicine and Pain
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• 제25권1호
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• pp.29-39
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• 2000

소(牛) 태아 대동맥으로 부터 Urea 추출, Sephacryl S200 HR 크로마토그라피, Cibacron blue-agarose 친화 크로마토그라피, 그리고 Sephacryl S300 HR 크로마토그라피를 이용하여 lysyl oxidase를 순수분리를 하였고 분리가간 중 항상 단백분해 억제제를 첨가하였다. 순수 분리된 효소는 가교결합이 없는 교원단백질과 엘라스틴에 활성을 보였고, BAPN 같은 아미노나이트릴에 의하여 억제되였다. Sephacryl S300 HR 크로마토그라피로 분리 될 경우, 이 효소는 0.45의 $K_{av}$ ($V_t$의 65%)값을 보였고, 이온교환 고속액체 크로마토그라피의 경우에서는 이온 강도가 0.1-0.15 사이에서 하나의 피크로 용리되었다. 순수 분리된 이 효소는 SDS 폴리아크릴아마이드 전기영동에서는 하나의 밴드로 이동하였는데, 환원이 될 경우에는 분자량이 33,500, 비환원이 될 경우에는 분자량이 24,500의 위치로 이동하였다. 이온교환 고속액체 크로마토그라피의 결과를 참조하여, 다른 보고서와는 달리 소(牛) 태아(服兒) 대동맥(大動服)에는 여러 종류가 아닌 한 종류의 lysyl oxidase가 존재한다고 결론을 내렸다.

• Journal of Chest Surgery
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• 제27권11호
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• pp.902-906
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• 1994

Between May 1991 and August 1993, 16 patients underwent repair of complete atrioventricular septal defect without another major anomaly at Cardiovascular Center,Yonsei University College of Medicine. Ages of the patients ranged from 3 months to 38 years with a mean of 42 months. Among 16, 10 patients[63%] are associated with Down`s syndrome. All patients underwent primary repair except and one who received had been repaire of coactation of aorta and patent ductus arteriosus 2 month before. Preoperative mitral valve regurgitation [MR] was evaluated with Doppler echocardiography and angiography which revealed absent or grade I in 1, grade II in 8, grade III in 4, and grade IV in 3. Operative technique was performed under the moderate hypothermic cardiopulmonary bypass with crystalloid cardioplegia. Intraoperative echocardiography was performed epicardial approach [n=7] in the operative table or transthoracic approach [n=9] at intensive care unit. In all patients except 3, MR were improved. But in 3 patients, was not improved or exagerated comparing preoperative one. All of them were died.One patient was showed MR grade IV in intraoperative echocardiography, we re-repaired atriventricular valve with cardiopulmonary bypass. During follow-up period [at a mean of 11 months after repair], doppler echocardiography was performed in all patients. The follow up echocardiography revealed that the degree of MR in immediate postoperative period was not changed except in two patients in whom it was aggravated. Thus it seems that intraoperative and early postoperative echocardiography was employed important role of survival and can be predictable for long term results.

• Journal of Magnetics
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• 제21권3호
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• pp.421-424
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• 2016

The purpose of this study is to evaluate an effectiveness of switching turbo direction to improve motion artifacts of small bowels and aorta. From June to October 2015, 60 patients suspected of having Crohn's disease were enrolled. The MR Enterography scans were performed using same protocol other than the turbo direction: with the Z phase encoding (group A) and with Y phase encoding (group B). Qualitative analysis of each group was performed to evaluate the effectiveness of switching turbo direction from Z to Y. As a result, the 5-point Likert scale for paired observers were $2.33{\pm}0.88$ for group A and $3.80{\pm}0.85$ for group B on dynamic contrast enhanced coronal images. In conclusion, group B is proved to be superior to group A and can lessen the motion artifacts derived from phase shifts.

• 대한자기공명의과학회:학술대회논문집
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• 대한자기공명의과학회 1999년도 제4차 추계학술대회 초록집
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• pp.105-105
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• 1999

• Korean Journal of Radiology
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• 제1권3호
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• pp.142-151
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• 2000

Objective: To determine the optimal scan timing for contrast-enhanced magnetic resonance angiography and to evaluate a new timing method based on the arteriovenous circulation time. Materials and Methods: Eighty-nine contrast-enhanced magnetic resonance angiographic examinations were performed mainly in the extremities. A 1.5T scanner with a 3-D turbo-FLASH sequence was used, and during each study, two consecutive arterial phases and one venous phase were acquired. Scan delay time was calculated from the time-intensity curve by the traditional (n = 48) and/or the new (n = 41) method. This latter was based on arteriovenous circulation time rather than peak arterial enhancement time, as used in the traditional method. The numbers of first-phase images showing a properly enhanced arterial phase were compared between the two methods. Results: Mean scan delay time was 5.4 sec longer with the new method than with the traditional. Properly enhanced first-phase images were found in 65% of cases (31/48) using the traditional timing method, and 95% (39/41) using the new method. When cases in which there was mismatch between the target vessel and the time-intensity curve acquisition site are excluded, erroneous acquisition occurred in seven cases with the traditional method, but in none with the new method. Conclusion: The calculation of scan delay time on the basis of arteriovenous circulation time provides better timing for arterial phase acquisition than the traditional method.

• Investigative Magnetic Resonance Imaging
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• 제2권1호
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• pp.96-103
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• 1998

목적 : 고식적인 자기공명혈관조영술 (MR Angiography, MRA) 기법으로는 영상화가 어려웠던 대동맥궁의 주요 분지들의 평가에 있어서 새로운 MR기법인 조영증강 MRA의 임상적 유용성을 알아보고, 그 화질을 사용한 코일의 종류에 따라 비교해 보고자 한다. 대상 및 방법 : 뇌혈관 질환을 의심하여 고식적인 기법으로 뇌 및 경동맥 MRA를 시행한 29명에서 전향적으로 Gd-DAPA 15-20ml를 일시에 손으로 주입한 후 대동맥궁과 그의 주요 분지들에 대해 3시기의 고속 MRA를 시행하여 그 화질을 분석하였다. MRA는 1.0T MR기종에서 3D-FISP기법으로 얻었으며 총 영상 획득 시간은 40-60초였다. 영상 분석은 무명동맥, 양측 총경동맥, 양측 쇄골하동맥과 양측 척추 동맥들의 기시부로부터 전장에 걸쳐 화질을 주관적으로 3등급(good; 명백히 정상소견을 보이는 경우, fair; 약간 낮은 신호를 보이나 정상으로 진단하기에 비교적 만족할 만한 경우, poor; 협착이 모호하거나, 인공물이나 너무 낮은 신호로 혈관을 볼 수 없어 카테터 혈관조영술을 요하는 경우)으로 나누어 평가하였으며, 양측 총경동맥의 분기(bifurcation) 부위에서는 고식적인 기법의 영상과 그 화질을 비교평가하였다. 또한 세가지 사용한 코일의 종류(CP body array 12예, CP neck array 9예, head-and-neck 8예)에 따른 화질 차이를 정성적 및 정량적(신호대 잡음비)으로 분석하였다. 결과 : 대동맥궁 주요 분지들의 전반적인 화질은 55% (16/29)에서 'good', 34%(10/29)에서 'fair'로 평가되어 대부분 고식적인 카테터 혈과조영술이 피요치 않을 정도로 만족할 만한 화질을 보였다. 양측 총경 동맥분지 부위에서는 65%(17/26)에서 고식적인 3D-TOF기법과 같거나 나은 영상을 보였다. CP body array 코일을 사용한 경우가 CP neck array 코일이나 head-and-neck 코일을 사용한 경우보다 정성적 및 정량적으로 유의하게 나은 영상을 보였다(p<0.05). 결론 : 고속 조영증강 MRA기법은 단시간내 (40-60초)에 대동맥구의 주요 분지들을 그 기시부위부터 두개골 저부에 이르기까지 대부분에서 잘 나타내주므로 선별검사로서 임상적으로 유용하리라 생각되며 CP body array 코일을 사용하였을 경우에 CP neck array 코일이나 head-and-neck 코일을 사용한 경우보다 좀더 나은 화질을 얻을 수 있으리라 생각된다.

• Journal of Chest Surgery
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• 제35권8호
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• pp.599-604
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• 2002

급성 혹은 만성 대동맥 해리증은 파열을 일으킬 수 있는데 이는 사망의 주요 원인이 된다. 상행대동맥의 해리성 동맥류(Stanford A형 대동맥 해리증)는 극히 드물게 상대정맥으로 파열되어 대동백-상대정맥루를 형성할 수 있는데 대동백-하대정맥루는 복부 대동맥류 환자에서 이따금씩 보고되어 왔다. 최근 상대정맥증후군의 증상을 가진 67세 남자환자에서 CT, MR angiography, 동맥촬영 등 방사선학적 검사결과 Stanford A형 대동맥 해리증 및 대동맥-상대정맥루가 진단되었다. 해리된 동맥류는 절제 후 인조혈관으로 치환되었고 대동맥-상대정맥루는 초저온 순환정지 상태에서 교정되었다. 이에 대해 상세하게 기술하는 바이다.