• Investigative Magnetic Resonance Imaging
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• v.1 no.1
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• pp.75-78
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• 1997

A dual birdcage RF coil is proposed for MRI and MRA of the human leg. The proposed coil c can be used to cover the whole human leg by imaging upper and lower parts of the leg separately. In the conventional leg imaging scheme using a single RF coil, the leg has to be r relocated when changing the position of the RF coil thus causing problems in matching the i images from two sets of coils. When using the proposed dual RF coil, however, only the bed h has to be moved to select the imaging region while only one part of the dual coil is used each t time by using current switching and PIN diodes. The utility of proposed coil has been verified b by volunteer MRI and MRA and the imaging results show that the coil is useful for the clinical MRI and MRA of the leg.

• Korean Journal of Radiology
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• v.2 no.3
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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.

• Investigative Magnetic Resonance Imaging
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• v.11 no.1
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• pp.33-38
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• 2007

Purpose : To investigate the applicability of the new three-dimensional overlapped reconstruction MR angiography (3-D ORMRA) technique in patients with hemifacial spasm and to compare the new 3-D reconstruction images with conventional MRA source images. Materials and Methods : The study group comprised 27 patients with surgically proven hemifacial spasm. In all patients, conventional MRA source images and 3-D fast imaging employing steady-state acquisition (FIESTA) images were obtained prospectively. After 3-D MR angiographic images were obtained, the 3-D MRA and FIESTA images were overlapped at the workstation by using GE A/W 4.2 add/sub software. We analyzed the relationship between the offending vessels and root exit zone of the facial nerve using both 3-D ORMRA images and conventional MRA source images. Results : In 25 of 27 patients, the offending vessel at the REZ of the facial nerve could be correctly identified on conventional MRA source images. In all patients, the presumed offending vessels depicted by the overlapped 3-D reconstruction MRA image corresponded well with the intraoperative findings. The 3-D reconstruction image showed more clear visualization of the spatial relationship between the offending vessels and the root exit zone of the facial nerve. Conclusion : The overlapped 3-D reconstruction MR angiography technique is very useful and informative in patients with hemifacial spasm, as compared with conventional MRA angiography technique.

• Proceedings of the KSMRM Conference
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• 2005.09a
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• pp.31-31
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• 2005

• Proceedings of the KSMRM Conference
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• 2001.11a
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• pp.15-19
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• 2001

지난 10년간 신경계의 MR영상은 컴퓨터를 비롯한 하드웨어적인 발달에 힘입어 functional imaging, perfusion imaging, diffusion imaging, MR spectroscopy, MR angiography 등의 분야에서 괄목한 만한 성장이 있었다. 지난 2001년 4월 국제자기공명의과학회 (ISMRM) 학술대회에 약 2300개의 논문이 발표되었으며 이 중 신경계와 관련된 논문의 수는 저자가 파악하기에 약 500개 정도이었다. 매년 수많은 논문이 발표되고 있으나 이 중 기초 또는 임상의학적으로 유용한 논문만이 후속 연구로 연결되어 궁극적으로 많은 사람들이 활용할 수 있게 되고 있다. 따라서 지난 수 년 동안의 연구 동향을 모두 follow-up하는 것은 무의미하며, 이 중 functional, perfusion, diffusion imaging을 중심으로 이들 영상 기법의 기술적 측면과 적용 분야를 알아보고자 한다.

• Journal of radiological science and technology
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• v.46 no.5
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• pp.427-433
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• 2023

This study aimed to quantitatively compare the diameters measured directly from the coronal plane or sagittal plane of 2D digital subtraction angiography (DSA) and the cross-sectional area-converted diameters calculated from contrast-enhanced MR (CE-MR) imaging. A retrospective analysis was conducted on 20 patients who underwent both 2D DSA and CE-MR imaging. Firstly, the venous diameters of the superior sagittal sinus (SSS) and transverse sinus (TS) were directly measured from 2D DSA. Subsequently, the axial planes for SSS diameter and the sagittal plane for TS in CE-MR imaging were utilized to calculate cross-sectional area-based converted diameters. The numerical values obtained from 2D DSA and CE-MR imaging were compared pairwise at each location. For SSS, the diameter measured by 2D DSA was 27% larger than the conversion-based diameter from CE-MR imaging (9.8±1.4 mm vs. 7.1±1.3 mm, P<0.05). Similarly, for the right TS, the difference was 16% (8.8±3.2 mm vs. 7.4±2.0 mm, P<0.05), and for the left TS, the difference was 22% (8.4±2.8 mm vs. 6.6±1.3 mm, P<0.05). In conclusion, the diameter measured directly in conventional 2D DSA may be larger than the diameter converted based on the cross-sectional area. Therefore, when selecting the size of the stent, it is crucial to make precise determinations while keeping this fact in mind.

• Journal of the Korean Society of Radiology
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• v.83 no.6
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• pp.1360-1365
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• 2022

Hutchinson-Gilford progeria syndrome (HGPS) is a rare, progressive, premature aging syndrome with early morbidity due to cardiovascular and cerebrovascular diseases. Clinical symptoms are very diverse, including non-specific symptoms such as growth retardation, scleroderma, alopecia, and osteoporosis, as well as hypertension and cardiovascular diseases that occur in childhood and adolescence due to accelerated vascular aging. In patients with HGPS, MR angiography is recommended for early diagnosis of asymptomatic stroke or vascular changes and to assess increased risk of cerebrovascular disease. We report the second domestic case of HGPS confirmed by genetic analysis in a 5-year-old child with typical clinical features, and the first English case report in Korea to present brain MR angiography findings.

• Investigative Magnetic Resonance Imaging
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• v.20 no.2
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• pp.105-113
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• 2016

Purpose: Susceptibility vessel sign (SVS) on gradient echo image, which is caused by MR signal loss due to arterial thrombosis, has been reported in acute middle cerebral artery (MCA) infarction. However, the reported sensitivity and diagnostic accuracy of SVS have been variable. Susceptibility-weighted imaging (SWI) is a newly developed MR sequence. Recent studies have found that SWI may be useful in the field of cerebrovascular diseases, especially for detecting the presence of prominent veins, microbleeds and the SVS. The purpose of this study was to evaluate the diagnostic values of SWI for the detection of hyperacute MCA occlusion. Materials and Methods: Sixty-nine patients (37 males, 32 females; 46-89 years old [mean, 69.1]) with acute stroke involving the MCA territory underwent MR imaging within 6 hours after the symptom onset. MR examination included T2, FLAIR (fluid-attenuated inversion recovery), DWI, SWI, PWI (perfusion-weighted imaging), contrast-enhanced MR angiography (MRA) and contrast-enhanced T1. Of these patients, 28 patients also underwent digital subtraction angiography (DSA) within 2 hours after MR examination. Presence or absence of SVS on SWI was assessed without knowledge of clinical, DSA and other MR imaging findings. Results: On MRA or DSA, 34 patients (49.3%) showed MCA occlusion. Of these patients, SVS was detected in 30 (88.2%) on SWI. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of SWI were 88.2%, 97.1%, 96.8%, 89.5% and 92.8%, respectively. Conclusion: SWI was sensitive, specific and accurate for the detection of hyperacute MCA occlusion.

• Proceedings of the KSMRM Conference
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• 2008.04a
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• pp.70-75
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• 2008

• Proceedings of the KSMRM Conference
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• 1996.10a
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• pp.85-87
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• 1996