• 대한자기공명의과학회:학술대회논문집
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• 대한자기공명의과학회 2002년도 제7차 학술대회 초록집
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• pp.117-122
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• 2002

Contrast-enhanced MR angiography has become a widely used method useful for clinical diagnosis. Early studies identified a number of technical issues, and many of these have been addressed with various MRI physics innovations over the last several years. The quality of the results is high enough that CE MRA is replacing conventional x-ray angiography methods at many institutions. Ongoing research is expected to provide further improvements in performance, most notably in additional reductions in examination time, in time-resolved 3D imaging, and in improved imaging of the peripheral vasculature with extended fields of view.

• Investigative Magnetic Resonance Imaging
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• 제23권4호
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• pp.374-380
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• 2019

Collision tumor is a synchronous neoplasm wherein two histologically distinct tumors co-exist within the same anastomosis site. Collision tumor can occur in any organ, but the incidence is markedly rare. Additionally, preoperative diagnosis can be challenging to the radiologist. Herein, we report an age 60 male with collision tumor of rectal adenocarcinoma and diffuse large B-cell lymphoma, presented as a semi-annular wall thickening and bulky exophytic mass on MR imaging.

• Investigative Magnetic Resonance Imaging
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• 제18권2호
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• pp.176-181
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• 2014

유방의 일차성 비호지킨림프종은 드문 종양으로 유방촬영술과 초음파에서 다양한 영상소견을 보인다. 하지만 자기공명영상소견은 여러개의 증례로만 보고되어 있고, 자기공명분광법과 확산강조영상에 대한 보고는 거의 없다. 저자들은 유방의 일차성 비호지킨림프종을 진단받은 두명의 여자환자의 증례를 기본 자기공명영상에 더하여 자기공명 분광법 및 확산강조 영상소견과 함께 보고하고자 한다. 종양은 유방촬영술과 초음파에서 경계가 좋은 종괴로 나타났으며, 조영증강자기공명영상에서 강한 조영증강을 보였다. 또한 다른 악성종양에서 나타나는 것과 같이 확산강조영상에서는 확산제한을 보이고, 자기공명분광법에서는 콜린값이 증가하는 소견을 보였다.

• 대한의용생체공학회:의공학회지
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• 제20권3호
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• pp.283-290
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• 1999

Mr(Magnetic Resonance ) 영상은 인체 기관의 상태에 관한 많은 정보를 가지고 있어 이것을 분석하여 가시화하면 의료 진단에 유용하게 이용될 수 있다. MR 영상의 가시화는 영상의 획득, 전처리, 조직 분류, 보간, 렌더링의 단계로 이루어진다. 이 단계 중 Mr 영상의 불완전성 때문에 현재 조직 분류 및 보간이 문제로 되어 있다. 본 논문에서는 머리 MR 영상을 대상으로 조직 분류 및 보간에 대한 기법을 제안하고 제안된 기법을 바탕으로 뇌를 3차원 가시화한다. 조직 분류 기법에서는 뇌조직 성분 구성 등 임상 실험에 의해 밝혀진 뇌에 대한 구조적인 지식을 단계적으로 이용한다. 보간 기법은 오목 윤곽선에 사용할 수 있게 동적 탄성 보간기법을 개선하였다. 제안한 구조적인 분류 기법 및 보간 기법을 다른 기법과 비교 평가한다.

• Clinical and Experimental Pediatrics
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• 제55권10호
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• pp.397-402
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• 2012

Pelizaeus-Merzbacher disease (PMD) is a rare, X-linked recessive disorder characterized by dysmyelination in the central nervous system. PMD results from deletion, mutation, or duplication of the proteolipid protein gene (PLP1) located at Xq22, leading to the failure of axon myelination by oligodendrocytes in the central nervous system. PMD may be suspected when there are clinical manifestations such as nystagmus, developmental delays, and spasticity, and genetic analysis can confirm the diagnosis. Further diagnostic manifestations of the disease include a lack of myelination on brain magnetic resonance (MR) imaging and aberrant N-acetyl aspartate (NAA) and choline concentrations that reflect axonal and myelination abnormalities on phroton MR spectroscopy. We report 5 cases of PMD (in 1 girl and 4 boys). PLP1 duplication was detected in 2 patients. Brain MR analyses and MR spectroscopy were performed for all the patients. The brain MR images showed white matter abnormalities typical of PMD, and the MR spectroscopic images showed diverse patterns of NAA, creatinine, and choline concentrations. We propose that MR spectroscopic analysis of metabolic alterations can aid the PMD diagnosis and can contribute to a better understanding of the pathogenesis of the disease.

• Archives of Plastic Surgery
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• 제46권4호
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• pp.375-380
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• 2019

Breast tissue expanders (TEs) with magnetic infusion ports are labeled "MR Unsafe." Therefore, patients with these implants are typically prevented from undergoing magnetic resonance imaging (MRI). We report a patient with a total submuscular breast TE who inadvertently underwent an MRI exam. She subsequently developed expander exposure, requiring explantation and autologous reconstruction. The safety profile of TEs with magnetic ports and the use of MRI in patients with these implants is surprisingly controversial. Therefore, we present our case report, a systematic literature review, and propose procedural guidelines to help ensure the safety of patients with TEs with magnetic ports that need to undergo MRI exams.

• Journal of Magnetics
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• 제19권4호
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• pp.365-371
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• 2014

The aim of this study was to evaluate the utility of 3-D images by comparing and analyzing reconstructed 3-D images from fast spin echo images of MRI cholangiopancreatography (MRCP) images using maximum intensity projection (MIP) with the subtraction images derived from dynamic tests of magnetic resonance mammography. The study targeted 20 patients histologically diagnosed with pancreaticobiliary duct disease and 20 patients showing pancreaticobiliary duct diseases, where dynamic breast MR (magnetic resonance) images, fast spin echo imaged of pancreaticobiliary duct, and 3-D reconstitution images using a 1.5T MR scanner and 3.0T MR scanner were taken. As a result of the study, the signal-to-noise ratio in the subtracted breast image before and after administering the contrast agent and in the reconstructed 3-D breast image showed a high ratio in the reconstructed image of lesional tissue, relevant tissue, and fat tissue. However, no statistically meaningful differences were found in the contrast-to-noise ratio of the two images. In the case of the MRCP image, no differences were found in the ratios of the fast spin echo image and reconstructed 3-D image.

• Investigative Magnetic Resonance Imaging
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• 제21권4호
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• pp.242-251
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• 2017

Purpose: To investigate the association of carotid intraplaque hemorrhage (IPH) with acute cerebral ischemic events and progression of stenosis using magnetic resonance (MR) imaging. Materials and Methods: From April 2014 to December 2016, 53 patients underwent carotid plaque MR imaging, including magnetization-prepared rapid acquisition with gradient-echo (MPRAGE) sequence. A total of 66 carotid arteries in 53 patients had carotid stenosis, and they were included in this study. Carotid arteries were classified according to the presence of IPH, the age of hemorrhage, and degree of stenosis. We assessed ipsilateral cerebrovascular event rates and progression of stenosis between the IPH and no-IPH groups. Results: Of the 61 carotid arteries assessed, 34 (56%) had IPH, and 27 (44%) had no IPH. Acute cerebral ischemic events were more frequent in the IPH group (47% vs. 22%, P = 0.045), especially in the < 30%-stenosis group (100% vs. 0%, P = 0.028). However, there was no significant difference in the incidence of ischemic events according to the age of hemorrhage (50% vs. 44%, P = 0.492). Among the 61 carotid arteries, 20 carotid arteries had previously undergone carotid artery imaging and were evaluated for plaque progression. The trend for progression of stenosis favored the IPH group versus the no-IPH group, with a marginal P-value ($20%{\pm}12.7$ vs. $9.6%{\pm}5.7$, P = 0.063). Conclusion: IPH was associated with an increased incidence of acute ischemic events, especially in the mild-stenosis group and it was also associated with progression of stenosis. Evaluation of the carotid IPH by carotid plaque MR could improve discrimination of carotid plaques that cause ischemic events and progression of stenosis.

• Investigative Magnetic Resonance Imaging
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• 제21권1호
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• pp.20-27
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• 2017

Purpose: To evaluate quantification results of single breath-hold (SBH) magnetic resonance (MR) cine imaging compared to results of conventional multiple breath-hold (MBH) technique for left ventricular (LV) function in patients with cardiac arrhythmia. Materials and Methods: MR images of patients with arrhythmia who underwent MBH and SBH cine imaging at the same time on a 1.5T MR scanner were retrospectively reviewed. Both SBH and MBH cine imaging were performed with balanced steady state free precession. SBH scans were acquired using temporal parallel acquisition technique (TPAT). Fifty patients ($65.4{\pm}12.3years$, 72% men) were included. End-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), myocardial mass, and LV regional wall motion were evaluated. Results: EF, myocardial mass, and regional wall motion were not significantly different between SBH and MBH acquisition techniques (all P-values > 0.05). EDV, ESV, and SV were significant difference between the two techniques. These parameters for SBH cine imaging with TPAT tended to lower than those in MBH. EF and myocardial mass of SBH cine imaging with TPAT showed good correlation with values of MBH cine imaging in Passing-Bablok regression charts and Bland-Altman plots. However, SBH imaging required significantly shorter acquisition time than MBH cine imaging ($15{\pm}7sec$ vs. $293{\pm}104sec$, P < 0.001). Conclusion: SBH cine imaging with TPAT permits shorter acquisition time with assessment results of global and regional LV function comparable to those with MBH cine imaging in patients with arrhythmia.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 추계종합학술대회 논문집
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• pp.525-528
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• 1999

Abstract - In this paper, a segmentation method for brain Magnetic Resonance(MR) image using region clustering technique with statistical distribution of gradient image and fuzzy rules is described. The brain MRI consists of gray matter and white matter, cerebrospinal fluid. But due to noise, overlap, vagueness, and various parameters, segmentation of MR image is a very difficult task. We use gradient information rather than intensity directly from the MR images and find appropriate thresholds for region classification using gradient approximation, rayleigh distribution function, region clustering, and merging techniques. And then, we propose the adaptive fuzzy rules in order to extract anatomical structures and diseases from brain MR image data. The experimental results shows that the proposed segmentation algorithm given better performance than traditional segmentation techniques.