• Korean Journal of Radiology
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• v.21 no.5
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• pp.561-571
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• 2020

Objective: To evaluate the clinical utility of ultrafast dynamic contrast-enhanced (DCE)-MRI compared to conventional DCE-MRI by studying lesion conspicuity and size according to the level of background parenchymal enhancement (BPE). Materials and Methods: This study included 360 women (median age, 54 years; range, 26-82 years) with 361 who had undergone breast MRI, including both ultrafast and conventional DCE-MRI before surgery, between January and December 2017. Conspicuity was evaluated using a five-point score. Size was measured as the single maximal diameter. The Wilcoxon signed-rank test was used to compare median conspicuity score. To identify factors associated with conspicuity, multivariable logistic regression was performed. Absolute agreement between size at MRI and histopathologic examination was assessed using the intraclass correlation coefficient (ICC). Results: The median conspicuity scores were 5 at both scans, but the interquartile ranges were significantly different (5-5 at ultrafast vs. 4-5 at conventional, p < 0.001). Premenopausal status (odds ratio [OR] = 2.2, p = 0.048), non-mass enhancement (OR = 4.1, p = 0.001), moderate to marked BPE (OR = 7.5, p < 0.001), and shorter time to enhancement (OR = 0.9, p = 0.043) were independently associated with better conspicuity at ultrafast scans. Tumor size agreement between MRI and histopathologic examination was similar for both scans (ICC = 0.66 for ultrafast vs. 0.63 for conventional). Conclusion: Ultrafast DCE-MRI could improve lesion conspicuity compared to conventional DCE-MRI, especially in women with premenopausal status, non-mass enhancement, moderate to marked BPE or short time to enhancement.

• Korean Journal of Radiology
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• v.25 no.4
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• pp.374-383
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• 2024

Objective: To evaluate the diagnostic performance and image quality of 1.5-mm slice thickness MRI with deep learningbased image reconstruction (1.5-mm MRI + DLR) compared to routine 3-mm slice thickness MRI (routine MRI) and 1.5-mm slice thickness MRI without DLR (1.5-mm MRI without DLR) for evaluating temporal lobe epilepsy (TLE). Materials and Methods: This retrospective study included 117 MR image sets comprising 1.5-mm MRI + DLR, 1.5-mm MRI without DLR, and routine MRI from 117 consecutive patients (mean age, 41 years; 61 female; 34 patients with TLE and 83 without TLE). Two neuroradiologists evaluated the presence of hippocampal or temporal lobe lesions, volume loss, signal abnormalities, loss of internal structure of the hippocampus, and lesion conspicuity in the temporal lobe. Reference standards for TLE were independently constructed by neurologists using clinical and radiological findings. Subjective image quality, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were analyzed. Performance in diagnosing TLE, lesion findings, and image quality were compared among the three protocols. Results: The pooled sensitivity of 1.5-mm MRI + DLR (91.2%) for diagnosing TLE was higher than that of routine MRI (72.1%, P < 0.001). In the subgroup analysis, 1.5-mm MRI + DLR showed higher sensitivity for hippocampal lesions than routine MRI (92.7% vs. 75.0%, P = 0.001), with improved depiction of hippocampal T2 high signal intensity change (P = 0.016) and loss of internal structure (P < 0.001). However, the pooled specificity of 1.5-mm MRI + DLR (76.5%) was lower than that of routine MRI (89.2%, P = 0.004). Compared with 1.5-mm MRI without DLR, 1.5-mm MRI + DLR resulted in significantly improved pooled accuracy (91.2% vs. 73.1%, P = 0.010), image quality, SNR, and CNR (all, P < 0.001). Conclusion: The use of 1.5-mm MRI + DLR enhanced the performance of MRI in diagnosing TLE, particularly in hippocampal evaluation, because of improved depiction of hippocampal abnormalities and enhanced image quality.

• Investigative Magnetic Resonance Imaging
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• v.6 no.1
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• pp.5-20
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• 2002

허혈성 심질환 환자의 평가도구로서 MRI의 역할이 확대된 데에는 소위 "one-stop shop"이라는 통합적 심장검사법의 개발이 계기가 되었다. 즉 한 번의 MRI 검사로서 심실벽운동을 평가하여 심근의 기능과 예비능을 측정하여 만성 심근경색을 평가할 수 있고, 심근의 관류를 평가할 수 있고, 관동맥의 혈류 예비능과 심근의 viability를 평가하고, 관동맥 조영술을 통해, 수술 후의 우회로 평가 및 관동맥의 협착 여부의 진단이 가능한 프로토콜이 MRI장비마다 각각 개발되어 보급되고 있다. 하드웨어와 소프트웨어의 개발과 지속적인 연구를 통해서 MRI는 허혈성 심질환의 진단적 검사로서 기존의 다른 검사들과 비교하여 높은 시간적, 공간적 해상력으로 정확한 구조와 기능의 평가를 제공할 수 있는 가장 유용한 검사가 될 것으로 사료된다 특히, MR 관동맥조영술, 심근관류검사, 심근 표지법, dobutamine 부하검사, viability 평가, plaque characterization, MR spectroscopy 분야에서 현재 활발히 연구가 진행되고 있으며 향후 임상적용이 확대될 것으로 예상된다.

• Journal of the Korean Society of Physical Medicine
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• v.2 no.1
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• pp.93-99
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• 2007

Purpose : The aim of this study is to consider degenerative spine disease theoretically and compare plain radiography which is a basic study for low back pain with MRI in cases of degenerative lumbar spine disease to find out whether the abnormalities agree with each other. Methods : In 4 cases of lumbar degenerative disease, we studied the relation of the abnormalities such as disc space narrowing, spinal space narrowing, loss of lordosis and osteophytes on plain radiography with those on MRI of HIVD, spinal stenosis and spondylolisthesis. Results : Many abnormalities such as disc space narrowing, spinal space narrowing, loss of lordosis, osteophytes and change of cortex & bone marrow on plain radiography suggest HIVD, spinal stenosis, spondylolysis or spondylolisthesis on MRI. Conclusion : For low back pain patients, plain radiography is a basic study in diagnosis of HIVD, spinal stenosis, spondylolysis or spondylolisthesis but MRI or CT scan is necessary to develop(build) a treatment plan like an operation.

• Childhood Kidney Diseases
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• v.13 no.1
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• pp.92-95
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• 2009

Rhabdomyolysis is a potentially life-threatening disease which may result from a variety of causes. We describe the features of magnetic resonance imaging(MRI) and bone scintigraphy, and their importance for diagnosis and treatment of a patient with rhabdomyolysis.

• Proceedings of the KOSOMBE Conference
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• v.1995 no.11
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• pp.173-176
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• 1995

We have developed a fast steady state free precession interferometry (SSFPI) technique which is useful for the fMRI (functional Magnetic Resonance Imaging). As is known, SSFP sequence with a suitable adjustment of gradient (readout) allows us to measure precession angle $\theta$ which is in turn related to the field inhomogeneity [1-3]. When the method is applied to the susceptibility effect based functional magnetic resonance imaging (fMRI), it was found that the direct susceptibility effect measurement was possible without perturbations such as the backgrounds and inflow effect. In this paper, simulation results and experimental results obtained with 2.0 Tesla MRI system are also presented.

• Journal of Pharmacopuncture
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• v.14 no.3
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• pp.99-107
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• 2011

Objectives : The purpose of this study is to report the image changes of two cases of Lumbar intervertebral Disc Sequestration after oriental medical treatment. Methods : We examined 2 patients with Lumbar intervertebral Disc Sequestration who showed changes on MRI images before/after the treatment. And we assessed clinical symptoms by using numeric rating scale(NRS) and straight leg raising test(SLRT). Results & Conclusions : In this study, the first MRI examination of Lumbar intervertebral Disc Sequestration patients was performed at the first visit and re-examination of MRI was done after treatment. In each case, the size of the disc sequestration was considerably reduced in MRI image. And both patients represented effective improvment in NRS score and SLRT test angle.

• Korean Journal of Radiology
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• v.23 no.4
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• pp.426-445
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• 2022

Endometriosis, a common chronic inflammatory disease in female of reproductive age, is closely related to patient symptoms and fertility. Because of its high contrast resolution and objectivity, MRI can contribute to the early and accurate diagnosis of ovarian endometriotic cysts and deeply infiltrating endometriosis without the need for any invasive procedure or radiation exposure. The ovaries, which are the most frequent site of endometriosis, can be afflicted by multiple related conditions and diseases. For the diagnosis of deeply infiltrating endometriosis and secondary adhesions among pelvic organs, fibrosis around the ectopic endometrial gland is usually found as a T2 hypointense lesion. This review summarizes the MRI findings obtained for ovarian endometriotic cysts and their physiologically and pathologically related conditions. This article also includes the key imaging findings of deeply infiltrating endometriosis.

• Korean Journal of Radiology
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• v.22 no.12
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• pp.1938-1945
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• 2021

Breast radiologists are increasingly seeing patients with axillary adenopathy related to COVID-19 vaccination. Vaccination can cause levels I-III axillary as well as cervical lymphadenopathy. Appropriate management of vaccine-related adenopathy may vary depending on clinical context. In patients with current or past history of malignancy, vaccine-related adenopathy can be indistinguishable from nodal metastasis. This article presents imaging findings of oncology patients with adenopathy seen in the axilla or neck on cross-sectional imaging (breast MRI, CT, or PET-CT) after COVID-19 vaccination. Management approach and rationale is discussed, along with consideration on strategies to minimize false positives in vaccinated cancer patients. Time interval between vaccination and adenopathy seen on breast MRI, CT, or PET-CT is also reported.

• Korean Journal of Radiology
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• v.22 no.3
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• pp.308-323
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• 2021

An increasing number of adult congenital heart disease (ACHD) patients continue to require life-long diagnostic imaging surveillance using cardiac CT and MRI. These patients typically exhibit a large spectrum of unique anatomical and functional changes resulting from either single- or multi-stage palliation and surgical correction. Radiologists involved in the diagnostic task of monitoring treatment effects and detecting potential complications should be familiar with common cardiac CT and MRI findings observed in patients with repaired complex ACHD. This review article highlights the contemporary role of CT and MRI in three commonly encountered repaired ACHD: repaired tetralogy of Fallot, transposition of the great arteries after arterial switch operation, and functional single ventricle after Fontan operation.