• Investigative Magnetic Resonance Imaging
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• v.12 no.2
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• pp.170-177
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• 2008

Purpose : To evaluate usefulness of MR imaging after serial brain US in the high-risk neonates before discharge of the neonatal intensive care unit. Materials and Methods : Retrospective comparison of 412 US and 121 MR scans in 121 neonates and young infants were performed. Grading of germinal matrix/intraventricular hemorrhage (GMH/IVH) was performed and presence of intracranial hemorrhage other than GMH/IVH and parencyma lesions was also analyzed. Results : Among the 242 lateral ventricles, Seven GMH and 46 IVH were additionally detected by MRI. On the other hand, 30 GMH were only detected by US. US demonstrated Grade 1/2/3/4 GMH/IVH in 24/8/13/0 ventricles each, while each grades were identified in 3, 49, 10, 2 ventricles on MR images. Other intracranial lesions additionally detected on MR images were cerebral hemorrhage (n=4), cerebellar hemorrhage (n=4), extraaxial hemorrhage (n=8), diffuse excessive signal change of the white matter (n=72), non-cavitary lesion (n=4), encephalomalacia (n=2), and ventriculomegaly (n=5). Conclusion : MR imaging could be an excellent complimentary study after serial brain US for additional detection of the intracranial pathology, particularly IVH and white matter lesions, though US would be better in follow-up of GMH in some neonates.

• Journal of the Korean Arthroscopy Society
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• v.16 no.2
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• pp.147-152
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• 2012

Purpose: The purpose of this study was to compare the preoperative magnetic resonance image (MRI) findings with postoperative arthroscopic findings on meniscus injury with anterior cruciate ligament (ACL) rupture. Materials and Methods: We reviewed MRI images and arthroscopic findings of 225 patients treated by ACL reconstruction due to rupture, from February 2001 to November 2010. There were 154 cases of meniscus tear in arthroscopic findings. We examined the sensitivity for detecting meniscal tears varied with the presence of a rupture of the ACL, with the location of the tear within the meniscus, and among configurations of meniscal tears. Results: In the presence of a rupture of the ACL, the sensitivity of MRI was 0.88 for medial meniscal tears and 0.69 for lateral meniscal tears. And sensitivity of MRI was lowest in posterior horn and peripheral portion tears in lateral meniscus injury accompanying ACL rupture, sensitivity was low in anterior horn and flap shape tears in medial meniscus injury accompanying ACL rupture. Conclusion: In Meniscus injury with ACL rupture, a special attention shoulder given to the posterior horn and peripheral portion injury in lateral meniscus during arthroscopic surgery due to difficulty in detecting on MRI.

• Investigative Magnetic Resonance Imaging
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• v.3 no.2
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• pp.113-124
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• 1999

종래의 영상진단 방법은 골수의 이상을 검사하는데 상당한 제한점이 있는 상황에서 MR 영상은 골수를 칩습한 병변을 직접 묘출할 있는 우선적인 영상진단법으로 그 이용이 점차 증대되고 이다. 비록 골수 천자나 생검에 비해 조직학적 진단의 특이성은 떨어지나 환자의 임상증세와 혈액상을 연관지어 MR 영상 소견을 판독하면 골수의 병변을 진단하고 그 치료에 관한 반응을 해석하는데 유용한 정보를 줄 수 있으리라 기대된다.

• Journal of the Korean Orthopaedic Association
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• v.53 no.6
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• pp.530-539
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• 2018

Purpose: We aimed to evaluate the magnetic resonance imaging (MRI) findings of congenital postaxial polydactyly of the foot. Materials and Methods: Three-hundred and forty-seven feet of 288 patients who underwent congenital postaxial polydactyly or polysyndactyly correction were divided into five subtypes according to the radiographic shapes of deformity origins (widened metatarsal head, bifid, fused duplicated, incompletely duplicated, or completely duplicated). MRIs were assessed to determine whether they unrevealed areas were fused or separated. MRI was also used to assess cases with radiographic phalangeal aplasia. Results: Huge variations were noted in MRIs. Fusion or separation at the base or head between original and extra digits were observed, and MRI effectively depicted phalangeal aplastic areas. Conclusion: MRI evaluations of congenital postaxial polydactyly of the foot are useful for determining the anatomical statuses which were not visualized by plain radiography (level of evidence: 3).

• Investigative Magnetic Resonance Imaging
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• v.3 no.2
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• pp.173-178
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• 1999

Purpose : To evaluate the usefulness of functional MRI (fMRI) of visual cortex in patients with ischemic infarction in the occipital lobe. Materials and Methods : Four patients with the symptoms and signs of visual cortical ischemia were included. Functional MRI was performed by 2D-FLASH technique with the parameter of 90/56msec TR/TE, $40^{\circ}$ flip angle, $240{\times}240{\;}FOV,{\;}64{\times}128$ matrix number, 8.32 seconds acquisition time, 8mm slice thickness. An axial slice including both visual cortices was selected and alternative activation and resting of the visual cortex was performed using red color photostimulator. all patients undertook visual field test, and vascular abnormality was examined by MRA (n=4) and DSA (n=2). fMRI results were compared with the results of a visual field test, conventional MRI and cerebral angiography. Results : On fMRI, decreased activity of the visual cortex was found in the occipital lobe corresponding to stenosis of the posterior cerebral artery or its branch noted on angiogram. However, 2 of 4 patients showed no abnormal findings on conventional MRI. Visual field defect was noted in 3 patients, one and of whom showed no abnormality on conventional MRI and diffusion-weighted image, but revealed decreased activity in the corresponding visual cortex on fMRI. Conclusion : fMRI may be a sensitive method for detection of the status of decreased blood flow or vascular reserve which other methods can not.

• Investigative Magnetic Resonance Imaging
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• v.17 no.2
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• pp.133-143
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• 2013

Purpose : To evaluate and compare the accuracy of magnetic resonance imaging (MRI) and ultrasound (US) for detection and estimation of invasion depth of colorectal carcinoma (CRC) by correlation with histopathologic findings in vitro, and to find out the best MR pulse sequence for accurate delineation of tumor from surrounding normal tissue. Materials and Methods: Resected specimens of CRC from 45 patients were examined about tumor detectability and invasion depth of US using high frequency (5-17 MHz) linear transducer in a tube filled with normal saline and MRI in a 8-channel quadrate head coil. The institutional review board approved this study and informed consent was waived. MRI with seven pulse sequences of in- and out-of-phases gradient echo T1 weighted images, fast spin echo T2 weighted image and its fat suppression image, fast imaging employing steady-state acquisition (FIESTA) and its fat suppression image, and diffusion weighted image (DWI) were performed. In each case, both imaging findings of MRI and US were evaluated independently for detection and estimation of invasion depth of tumor by consensus of two radiologists and were compared about diagnostic accuracy according to the histopathologic findings as reference standard. Seven MR pulse sequences were evaluated on the point of accurate delineation of tumor from surrounding normal tissue in each specimen. Results: In specimens of CRC, both imaging modalities of MRI (91.1%) and US (86.7%) showed relatively high diagnostic accuracy to detect tumor and evaluate invasion depth of tumor. In early CRC, diagnostic accuracy of US was 87.5% and that of MRI was 75.0%. There was no statistically significant difference between two imaging modalities (p > 0.05). The best pulse sequence among seven MR sequences for accurate delineation of tumor from surrounding normal tissue in each specimen of CRC was fast spin echo T2 weighted image. Conclusion: MRI and US show relatively high diagnostic accuracy to detect tumor and evaluate invasion depth of resected specimen of CRC. The most excellent pulse sequence of MRI for accurate delineation of tumor from surrounding normal tissue in CRC is fast spin echo T2 weighted image.

• Journal of Veterinary Clinics
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• v.27 no.6
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• pp.755-759
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• 2010

A 6-year-old, intact female Dachshund was presented with generalized seizure for 2 days. Based on the neurologic and physical examinations, intracranial diseases were suspected. 1.5T and 7.0T magnetic resonance imaging (MRI) of the brain were taken. The MRI results revealed diffuse hyperintense lesions in the area of the diencephalon to the medulla oblongata in the T2-weighted images. Canine distemper virus-induced meningoencephalitis was confirmed by the result of RT-PCR of the cerebrospinal fluid (CSF). The dog was euthanized 7 days after diagnosis due to poor prognosis and clinical deterioration. Postmortem histopathologic examination was consistent with the MRI findings. This is the first case report using 1.5T and 7.0T MRI to compare the virus-induced intracranial lesions in meningoencephalitis.

• Journal of Veterinary Clinics
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• v.24 no.2
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• pp.247-250
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• 2007

A 3-year-old, intact female English cocker spaniel dog was evaluated for an acute onset of tetraplegia. Utilizing magnetic resonance (MR) imaging, the cause of the neurologic deficits was determined to be an peracute hemorrhage of spinal cord. The MR study additionally demonstrated parenchymal hyperintensity on T2weighted images and similarly located hypointensity on T1weighted images. Hemorrhagic myelomalcia was suspected based on these MR characteristics, which was subsequently confirmed histopathologically.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.9
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• pp.1138-1143
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• 2020

MRI scans in the abdominal area are difficult to achieve optimal images due to artificial respiration. Among 45 patients (male:female = 30:15) who underwent abdominal MRI examination, a metronome-based examination method was studied for patients whose breathing is difficult and difficult to examine. The images examined without using a metronome were divided into group A, and the images examined using a metronome were divided into group B. Image quality improvement (30%) and inspection time (approximately 50 seconds) were reduced in images using metronome. During abdominal magnetic resonance imaging (ABD MRI), the images examined using a metronome had differences in quality and examination time compared to the unused images. It is more effective to use a metronome brace that controls the patient's respiratory rate during abdominal magnetic resonance imaging under respiratory induction in patients with difficulty in respiratory-gated.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.4 no.1
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• pp.1-6
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• 2011

Purpose: To evaluate the usefulness of ultrasonography in diagnosis of the medial meniscus tear as a screening tool before performing magnetic resonance imaging. Materials and Methods: From April 2009 to September 2010, magnetic resonance imaging (MRI) was taken in 147 knees out of 341 knees examined with ultrasonography (US) under the suspicion of medial meniscus tear. The sonographic findings were 16 without abnormality, 12 inhomogeneity, 4 cluster, 60 cleavage and 55 more than 5mm medial extrusion of medial meniscus. In Statistical analysis, sensitivity and specificity, positive predictive value and negative predictive values were calculated. Results: The MRI showed abnormality in 104 knees. Sensitivity and specificity of ultrasonography for MRI was 94.2% and 23.3%, respectively. Positive predictive value was 74.8%, negative predictive value was 62.5%. The positive predictive value of ultrasonography were 58.3% in heterogeneity, 100% in showing cluster, 75% in visible cleft and 80% in medial extrusion. Conclusion: The US is a useful tool in prediction of medial meniscus tear before confirming it in high-cost MRI.