• Annals of Clinical Neurophysiology
• /
• 제4권2호
• /
• pp.114-118
• /
• 2002

Backgrounds : Carpal tunnel syndrome (CTS) is a common condition that is usually diagnosed by electrophysiologic studies. However, CTS provide limited information to determine the causes of CTS and to choose the treatment method. We evaluated diagnostic sensitivity of MR imaging and treatment decisions by MR imaging in electrodiagnosed CTS. Methods : 14 patients (26 wrists) with electrodiagnosed CTS were studied using MR imaging. In 26 wrists for which axial T1 & T2 weighted images were obtained at 1.5T with a decided wrist coil. Previously described MR imaging of CTS such as increased median nerve signal, flattening of median nerve, reticular bowing, tenosynovitis and space occupying lesions were retrospectively evaluated. Degree of improvement was evaluated by global symptom score (GSS). The GSS rated symptoms from 0 (no symptoms) to 10 (severe) in each of five categories: pain, numbness, paresthesia, weakness/clumsiness, and nocturnal awakening. Subjects' GSS was recorded at baseline, 2 weeks, 1 month, 6 months after treatment. We decided to medical treatment that showed mainly inflammatory sign such as increased median nerve signal, tenosinovitis and to surgical treatment such as space occupying lesion, high canal pressure sign. Results : MR imaging showed that increased median nerve signal were in 20 wrists (77%), flattening of median nerve were in 6 wrists (23%), reticular bowing were in 3 wrists (12%), tenosynovitis were in 8 wrists (32%), decreased canal size in 2 wrists (7.6%), space occupying lesion were in 1 wrist (4%). A good outcome was revealed in 21 wrists by medical treatment that showed mainly increased median nerve signal, tenosynovitis. The mean GSS were 27.7 at baseline, 11.2 at 2 weeks, 11.0 at 6 months in medical treatment group. Another 5 wrist had surgical treatment shown by ganglion and high canal pressure sign such as median nerve flattening, reticular bowing, decreased canal size: 3 wrists had good prognosis, but 2 wrists (one patient) had no significant improvement due to small carpal tunnel size. Conclusions : Our results are in agreement with most previously described MR imaging signs of CTS. MR imaging plays an important role in several cases and especially in the assessment of failure of surgical treatment. Knowledge of MR findings may permit more rational choice of treatment.

• Investigative Magnetic Resonance Imaging
• /
• 제3권1호
• /
• pp.73-77
• /
• 1999

목적: 슬관절 반월판 열상의 진단에 있어서 양자밀도강도 고속스핀에코영상을 수술소견과 비교하여 진단의 민감도 및 특이도를 분석하여 고식적스핀에코의 대체 방법으로 사용할 수 있는가 알아보고자 하여다. 대상 및 방법: 임상적으로 슬관절 내장층이 의심되어 슬관절 자기공명영상 검사를 시행하고 2개월 이내에 관절경 또는 관혈적 수술을 시행하여 결과가 확진된 102명을 대상으로 하였다. 모든 환자에서 1.5T 영상장치를 사용하여 시상면 및 관상면 양자밀도강도 고속스핀에코 자기공명영상 검사를 시행하였다. 수술 결과를 모르는 3명의 방사선과 의사가 후향적으로 반월판 파열 유무에 대해 분서하고 내측 및 외측 반월판 열상의 민감도 및 특이도를 구하였다. 결과: 양자밀도강조 고속스핀에코 자기공명영상으로 분석한 슬관절 반월판 열상의 민감도 및 특이도는 내측 반월판의 경우 각각 94%, 93% 였고 외측이 경우는 각각 92%, 88% 였다. 결론: 양자밀도강조 고속 스핀에코영상은 반월판 열상의 진단에서 고식적 스핀에코영상과 유사하게 높은 민감도와 특이도를 보였다. 따라서 반월판 영상을 진단하는데 고식적 스핀에코영상의 대체방법으로 사용할 수 있을 것으로 생각한다.

• 한국임상수의학회지
• /
• 제30권4호
• /
• pp.320-323
• /
• 2013

척수 경색은 고양이에서 급성 척수 병증의 주요한 원인으로써 인식되고 있다. 사후 조직 병리학적 검사를 통해 확진 할 수 있지만 MR 영상학적 특징은 척수 경색의 진단에 가치있는 정보를 제공한다. 본 증례의 목적은 두 마리의 고양이에서 발생한 급성 척수 경색의 영상학적 특징을 설명하고 그 진단에 있어서 low field MRI (0.3 Tesla)의 유용성을 평가하는 것이다. 미확인 연령의 중성화 수컷, mixed breed 고양이가 급성의 사지 부전 마비를 주증으로 내원하였고 9살령의 중성화 암컷 domestic short hair 고양이는 후지 부전 마비로 내원하였으며 하루 후 후지 완전 마비가 나타났다. 이후 실시된 MR 영상에서 첫번째 고양이의 경우 두번째 경추부터 여섯번 째 경추 수준의 척수에서 병변이 분포하였으며 두번째 고양이의 경우 두번째 요추부터 다섯번째 요추 수준에서 병변이 나타났다. 두 고양이에서 공통적으로 주로 회백질에 분포한 척수 실질 내에 국소적인 병변이 확인되었으며 T2 강조 영상 및 FLAIR 영상에서 고신호를 나타내었고 DWI 영상에서 고신호, ADC map 에서는 저신호를 나타내었다. 히스토리, 임상증상 및 다른 실험실적 검사와 함께 MR 영상학적 특징을 통해 두 고양이에서 급성 척수 경색이 진단되었다.

• 대한방사성의약품학회지
• /
• 제3권1호
• /
• pp.25-31
• /
• 2017

Liposomes are defined as spherical, self-closed structures formed by lipid bilayers containing aqueous phase. Most liposomes are composed of various amphipathic lipids such as phospholipids and cholesterol. We used amphipathic lipids (DPPC, DPPG) as liposome components and prepared around 100 nm liposomes by standard extrusion method. Nuclear/MR dual imaging agents based on liposome platform were prepared by adding radioactive $^{131}I$-HIB (hexadecyl-4-tributylstannylbenzoate) and Gd-DTPA into liposome bilayer and inside liposome, respectively. Gamma camera and MR imaging both showed signal increases in liver.

• 대한방사선기술학회지:방사선기술과학
• /
• 제46권5호
• /
• pp.427-433
• /
• 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.

• 대한의용생체공학회:학술대회논문집
• /
• 대한의용생체공학회 1997년도 춘계학술대회
• /
• pp.230-234
• /
• 1997

The matching pursuit (MP) algorithm developed by S. Mallat and Z. Zhang is applied to magnetic resonance (MR) imaging. Since matching pursuit is a greedy algorithm to find waveforms which are the best match for an object-signal, the signal can be decomposed with a few iterations. In this paper, we propose an application of the MP algorithm to the MR imaging to reduce imaging time. Inner products of residual signals and selected waveforms in the MP algorithm are derived from the MR signals by excitation of RF pulses which are fourier transforms of selected waveforms. Results from computer simulations demonstrate that the imaging time is reduced by using the MP algorithm and further a progressive reconstruction can be achieved.

• Korean Journal of Radiology
• /
• 제2권3호
• /
• pp.151-158
• /
• 2001

Objective: To determine the ability of MR imaging to detect the pathological changes occurring in radiofrequency (RF) thermal lesions and to assess its accuracy in revealing the extent of tissue necrosis. Materials and Methods: Using an RF electrode, thermal lesions were created in the livers of 18 rabbits. The procedure involved three phases. In the acute phase, six animals were killed the day after performing thermal ablation with RF energy, and two on day 3. In the subacute and chronic phases, eight rabbits underwent percutaneous hepatic RF ablation. After performing MR imaging, two animals were sacrificed at 1, 2, 4, and 7 weeks after the procedure, and MRpathologic correlation was performed. Results: In the acute phase, the thermal ablation lesions appeared at gross examination as well-circumscribed, necrotic areas, representing early change in the coagulative necrosis seen at microscopic examination. They were hypointense on T2-weighted images, and hyperintense on T1-weighted images. Gadolinium-enhanced MR imaging showed that a thin hyperemic rim surrounded the central coagulative necrosis. In the subacute phase, ablated lesions also showed extensive coagulative necrosis and marked inflammation at microscopic examination. Beyond two weeks, the lesions showed gradual resorption of the necrotic area, with a peripheral fibrovascular rim. The size of lesions measured by MR imaging correlated well with the findings at gross pathologic examination. Conclusion: MR imaging effectively demonstrates the histopathological tissue change occurring after thermal ablation, and accurately determines the extent of the target area.

• Journal of Korean Neurosurgical Society
• /
• 제47권6호
• /
• pp.437-441
• /
• 2010

Objective : The precise intra- vs. extradural localization of aneurysms involving the paraclinoid internal carotid artery is critical for the evaluation of patients being considered for aneurysm surgery. The purpose of this study was to investigate the clinical usefulness of T2-weighted threedimensional (3-D) fast spin-echo (FSE) magnetic resonance (MR) imaging in the evaluation of unruptured paraclinoid aneurysms. Methods : Twenty-eight patients with unruptured cerebral aneurysms in their paraclinoid regions were prospectively evaluated using a T2- weighted 3-D FSE MR imaging technique with oblique coronal sections. The MR images were assessed for the location of the cerebral aneurysm in relation to the dural ring and other surrounding anatomic compartments, and were also compared with the surgical or angiographic findings. Results : All 28 aneurysms were identified by T2-weighted 3D FSE MR imaging, which showed the precise anatomic relationships in regards to the subarachnoid space and the surrounding anatomic structures. Consequently, 13 aneurysms were determined to be intradural and the other 15 were deemed extradural as they were confined to the cavernous sinus. Of the 13 aneurysms with intradural locations, three superior hypophyseal artery aneurysms were found to be situated intradurally upon operation. Conclusion : High-resolution T2-weighted 3-D FSE MR imaging is capable of confirming whether a cerebral aneurysm at the paraclinoid region is intradural or extradural, because of the MR imaging's high spatial resolution. The images may help in identifying patients with intradural aneurysms who require treatment, and they also can provide valuable information in the treatment plan for paraclinoid aneurysms.

• 대한의생명과학회지
• /
• 제10권3호
• /
• pp.285-291
• /
• 2004

To determine the magnetic resonance (MR) imaging findings and natural history of cerebral fat embolism in a cat model, and to correlate the MR imaging and histologic fmdings. Intemel carotid artery of 11 cats was injected with 0.1 ml of triolein. T2-weighted, T1-weighted and Gd-enhanced T1-weighted images were obtained serially for 2 hours, 1 days, 4 days, 1 week, 2 weeks and 3 weeks after embolization. Any abnormal signal intensity was evaluated. After MR imaging at 3 weeks, brain tissue was obtained for light microscopic (LM) examination using hematoxylin-eosin (HE) and Luxol fast blue staining, and for electron microscopic examination. The LM examination with HE staining revealed normal histological findings in the greater part of an embolized lesion. Cystic change was observed in the gray matter of 8 cats, while in the gray and white matter of 3 cats. At LM examination, Luxol fast blue, staining demonstrated demyelination around the cystic change occurring in the white matter, and EM examination of the embolized cortex revealed sporadic intracapillary fat vacuoles (n=11) and disruption of the blood-brain barrier (n=4). Most lesions were normal, however, and perivascular interstitial edema and cellular swelling were mild compared with the control side. The greater part of an embolized lesion showed reversible findings at MR and histological examination. Irreversible focal necrosis was, however, observed in gray and white matter at weeks 3.

• Journal of Yeungnam Medical Science
• /
• 제8권1호
• /
• pp.220-230
• /
• 1991

Internuclear ophthalmoplegia is a conjugated gaze disorder characterized by impaired adduction on the side of a lesion involving the medial longitudinal fasciculus with dissociated nystagmus of the other abducting eye. Six patients with INO(who had clinical cerebrovascular diseases) underwent MR imaging and the results were as follows : 1. The MLF lesions were identified by MR imaging in 5 cases 2. The ratio of unilateral INO to bilateral INO was 5:1 3. The nature of lesions was infarction in 4 cases and hemorrhage in 1 case 4. The sites of MLF lesion were in the midbrain in 4 cases and in the pons in 1 case 5. All 5 cases of INO identified by MR imaging had other lesion sites in addition to MLF lesion.