• Journal of the Korean Arthroscopy Society
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• v.13 no.1
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• pp.14-21
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• 2009

Purpose: To investigate MRI findings of the repaired anterior cruciate ligament (ACL). Materials and Methods: Seventeen of arthroscopic ACL primary repair with sutures pull-out technique were followed for 21.4 months (range: 12 to 60 months). Stability was assessed with physical examination and KT-1000 arthrometer (MED metric, San Diego, CA) and postoperative MRI checked with time. The patients were divided into 2 groups according to the location of tear which was defined with the location of remained synovial sleeve. Group I (11 patients) comprised that the tear was located within proximal 1/3 of ACL substance and group II (6 patients) comprised below proximal 1/3. MRI findings of the repaired ACL were evaluated by its course, sharpness, thickness and signal intensity using 3 grade system and correlated with its location of tear. Results: In all cases, Lachman test and flexion-rotation drawer test were negative, pivot-shift test was less than grade 1 and the mean side-to-side difference by use of KT-1000 arthrometer was 1.4 mm (range: -1.0 to 2.5 mm). The overall continuity of the repaired ACL was well maintained in all cases. However, mild sagging was observed in 10 cases(58.8%), mild obscure contour in 6 cases (35.3%), increased thickness in 8 cases (47.1%) and slight increased signal intensity in 5 cases (29.5%). There was no statistical significance in all parameters between 2 groups. And a focal defect at the femoral attachment site in sagittal image was observed in 7 cases (41.2%) of all patients which comprised 2 cases (18.2%) of group I and 5 cases (83.3%) of group II. It was observed more frequently in group II with statistical significance (p=0.035). Conclusion: Some abnormal MRI findings such as mild sagged course, obscure contour, increased thickness and signal intensity, the focal defect at femoral attachment site could be observed even though the stability was well maintained clinically. We thought that the focal defect was affected by the location of tear of ACL.

• Korean Journal of Radiology
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• v.22 no.5
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• pp.725-734
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• 2021

Objective: To intraindividually compare hepatocellular carcinoma (HCC) washout between MRIs using hepatobiliary agent (HBA) and extracellular agent (ECA). Materials and Methods: This study included 114 prospectively enrolled patients with chronic liver disease (mean age, 55 ± 9 years; 94 men) who underwent both HBA-MRI and ECA-MRI before surgical resection for HCC between November 2016 and May 2019. For 114 HCCs, the lesion-to-liver visual signal intensity ratio (SIR) using a 5-point scale (-2 to +2) was evaluated in each phase. Washout was defined as negative visual SIR with temporal reduction of visual SIR from the arterial phase. Illusional washout (IW) was defined as a visual SIR of 0 with an enhancing capsule. The frequency of washout and MRI sensitivity for HCC using LR-5 or its modifications were compared between HBA-MRI and ECA-MRI. Subgroup analysis was performed according to lesion size (< 20 mm or ≥ 20 mm). Results: The frequency of portal venous phase (PP) washout with HBA-MRI was comparable to that of delayed phase (DP) washout with ECA-MRI (77.2% [88/114] vs. 68.4% [78/114]; p = 0.134). The frequencies were also comparable when IW was allowed (79.8% [91/114] for HBA-MRI vs. 81.6% [93/114] for ECA-MRI; p = 0.845). The sensitivities for HCC of LR-5 (using PP or DP washout) were comparable between HBA-MRI and ECA-MRI (78.1% [89/114] vs. 73.7% [84/114]; p = 0.458). In HCCs < 20 mm, the sensitivity of LR-5 was higher on HBA-MRI than on ECA-MRI (70.8% [34/48] vs. 50.0% [24/48]; p = 0.034). The sensitivity was similar to each other if IW was added to LR-5 (72.9% [35/48] for HBA-MRI vs. 70.8% [34/48] for ECA-MRI; p > 0.999). Conclusion: Extracellular phase washout for HCC diagnosis was comparable between MRIs with both contrast agents, except for tumors < 20 mm. Adding IW could improve the sensitivity for HCC on ECA-MRI in tumors < 20 mm.

• Journal of the Korean Society of Radiology
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• v.83 no.4
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• pp.938-944
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• 2022

Spinal epidermoid cysts are extremely rare benign tumors and can be congenital or acquired. Acquired spinal epidermoid cysts are found in the lumbosacral region. To our knowledge, no case of epidermoid cyst related to spinal cord stimulator insertion has yet been reported. We report the MRI findings of a rare case of thoracic intradural epidermoid cyst acquired after spinal cord stimulator insertion in a 50-year-old female.

• Journal of the Korean Society of Radiology
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• v.82 no.5
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• pp.1334-1340
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• 2021

Amyloidosis has been reported to be associated with non-Hodgkin lymphoma. Amyloidosis and lymphoma can be related in two ways: lymphoma-associated systemic amyloidosis and peritumoral amyloidosis with lymphoma. We report a rare case of peritumoral amyloidosis in a patient with head and neck mucosa-associated lymphoid tissue lymphoma. On CT, the oropharyngeal mass showed an irregularly shaped soft-tissue density with multifocal amorphous calcifications and heterogeneous enhancement. On MRI, the mass showed heterogeneous low signal intensity on both T1- and T2-weighted images. On contrast-enhanced MR images, the mass showed good enhancement with several inner non-enhancing foci. Concurrent pathologies, such as peritumoral amyloidosis, should be considered when calcifications are noted in patients with pre-treatment lymphoma.

• Journal of the Korean Society of Radiology
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• v.85 no.1
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• pp.247-251
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• 2024

Respiratory epithelial adenomatoid hamartoma (REAH) in the head and neck is a rare benign lesion containing glandular tissue covered with ciliated respiratory epithelium. In the head and neck, REAH of the nasal cavity, paranasal sinuses, and nasopharynx have been reported in literature. Due to rareness of REAH and insufficient knowledge of its imaging features, the diagnosis can be challenging when we encounter a non-specific cystic mass at an uncommon site in the head or neck. Here, we report the case of a pathologically confirmed REAH showing a cystic mass centered at the buccal space (retromaxillary fat pad) with CT and MRI findings.

• Journal of the Korean Society of Radiology
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• v.84 no.3
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• pp.745-749
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• 2023

Gerstmann-Sträussler-Scheinker (GSS) disease is a rare hereditary prion disease which is clinically characterized by a progressive cerebellar ataxia followed by cognitive impairment. We report a rare case of GSS disease in a 39-year-old male patient who complained of a progressive gait disturbance followed by dysarthria with cognitive impairment, after five months from the onset of initial symptom. His brain MRI scan revealed multifocal symmetric diffusion restricted lesions with T2/FLAIR hyperintensities in bilateral cerebral cortices, basal ganglia, and thalami. His family members also manifested similar symptoms in their 40-50s, suggesting the possibility of a genetic disease. Finally, he was genetically diagnosed with GSS disease by real-time quaking-induced conversion and prion protein (PRNP) gene sequencing test.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1528-1535
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• 1997

Many radiological modalities has been applied to medicine as a basic fundamental diagnosis and therapy recently. The prevalence of computer systems affect most images to be digitized. However conventional X-ray film images are not digital images eventhough they covers 70% of all radiologica images. This is the hinderacne of building PACS. In this paper all radiological digital imaging parts such as DSA. CR. MRI. SPECT. PET and ultrasonography were briefly introduced and the applications were described. In brief digital radiography contribute to enhance the medical service quality. And the digital substituition of conventional X-ray film image is inevitable.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.5
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• pp.663-666
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• 2013

This paper demonstrates four different radio frequency (RF) resonators at 3 T magnetic resonance imaging (MRI) system. An approach based on microstrip transmission line to identical RF resonators except upper stripline structure is investigated. Electromagnetic simulation results are compared for RF resonators and discussed in detail at 3 T.

• Proceedings of the Korea Contents Association Conference
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• 2017.05a
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• pp.111-112
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• 2017

MRI는 부분 영역을 자세히 영상화하는 검사임에도 인체에 위해한 RF를 전신에 주고 있다. 이러한 문제점을 개선하기 위해 저자들은 RF차단 방호복을 자제제작하여 적용한 결과 적용 전보다 적용 후가 95% 이상 RF를 차단하였다. 따라서 MRI 검사 시 본 연구의 방호복이 인체의 위해를 줄일 수 있는 최적의 대안임을 알 수 있다.

• Korean Journal of Radiology
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• v.23 no.9
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• pp.931-934
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• 2022