• 제목/요약/키워드: 7T-MRI

검색결과 361건 처리시간 0.028초

만성 족관절 외측 불안정성에 대한 $Brostr{\ddot{o}}m$ 변형 술식 (The Modified $Brostr{\ddot{o}}m$ Procedure for Chronic Lateral Ankle Instability)

  • 송하헌;심대무;이병창;김동철;조용우;양정환
    • 대한족부족관절학회지
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    • 제8권1호
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    • pp.81-85
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    • 2004
  • Purpose: The purpose of this study is to evaluate the surgical results of modified $Brostr{\ddot{o}}m$ procedure for chronic lateral ankle instability and to assess whether or not associated injuries may affect postoperative satisfaction. Materials and Methods: Twenty- four patients with chronic lateral ankle instability were evaluated retrospectively from August 1998 to March 2002. Average age was 29.3 years. All patients were performed pre & postoperative ankle anteroposterior and lateral view, stress anterior drawer and varus test using Telos device, MRI and intraoperative arthroscopic evaluations before ligament reconstruction. Results: Of the 24 cases, 23 cases was improved more than average 12 points on AOFAS scales. On modified scales of Hamilton, 3 excellent, 20 good, 1 fair results. On stress view, average 2.2 mm difference was improved on anterior drawer test and average 1.7 degree on varus test. Associated injuries were 8 osteochondral defects, 4 anterior impingements, 2 loose bodies, 2 os subfibulare, 2 os submalleolare and 2 partial ruptures of peroneus brevis. 8 cases with no associated injuries rated excellent or good. Conclusion: The modified $Brostr{\ddot{o}}m$ procedure is believed to be an effective and successful method for chronic lateral ankle instability that didn't respond to conservative treatment. Because associated injuries in chronic lateral ankle instability may affect postoperative satisfaction, appropriate detection and treatment may need for postoperative satisfaction.

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턱관절원판 전방 변위로 인한 개구 장애의 템플레이트 치료 (Template therapy for mouth opening limitation by temporomandibular joint disorders)

  • 이기철;신승우;표성운
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제36권4호
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    • pp.270-274
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    • 2010
  • Introduction: Limited mouth opening is a representative clinical symptom of temporomandibular disorders (TMD) with anterior disc displacement without reduction (ADDWOR). Various treatment methods have been proposed for patients with ADDWOR. This study examined the clinical effectiveness of template therapy for patients with mouth opening difficulty due to the ADDWOR. Material and Methods: A total of 14 patients (female 12, male 2, average age: $29.1{\pm}14.4$), who had been treated in the template clinic, Sooncheonhyang University Bucheon Hospital, from January of 2006 to December of 2008, were enrolled in this study. The subjects were selected according to the following criteria: more than 2 weeks after the onset of locking, mouth opening range <35 mm, and confirmed ADDWOR without a synovial pathology by magnetic resonance imaging (MRI). All patients were treated with the template appliance, instructed to wear it while sleeping and exercise for at least 10 hours per day. The maximum mouth opening (MMO) range and pain recognition scores before and after template therapy were recorded and compared. A paired t-test and Wilcoxon's signed rank test were used for statistical analysis. Results: After the periodical follow up, significant improvement in the opening range was observed in the template treatment group. The average MMO range before treatment was $30.2{\pm}3.5mm$ and the average MMO after treatment and follow up was $47.1{\pm}4.7mm$. The mean amount of mouth opening increment was $16.9{\pm}5.4mm$ (P<0.01) and the pain recognition scores before and after treatment was also improved.(P=0.001) Conclusion: The template appliance proved to be efficient for the treatment of TMD with a closed lock and painful joint due to ADDWOR.

Optimization of Multi-Atlas Segmentation with Joint Label Fusion Algorithm for Automatic Segmentation in Prostate MR Imaging

  • Choi, Yoon Ho;Kim, Jae-Hun;Kim, Chan Kyo
    • Investigative Magnetic Resonance Imaging
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    • 제24권3호
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    • pp.123-131
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    • 2020
  • Purpose: Joint label fusion (JLF) is a popular multi-atlas-based segmentation algorithm, which compensates for dependent errors that may exist between atlases. However, in order to get good segmentation results, it is very important to set the several free parameters of the algorithm to optimal values. In this study, we first investigate the feasibility of a JLF algorithm for prostate segmentation in MR images, and then suggest the optimal set of parameters for the automatic prostate segmentation by validating the results of each parameter combination. Materials and Methods: We acquired T2-weighted prostate MR images from 20 normal heathy volunteers and did a series of cross validations for every set of parameters of JLF. In each case, the atlases were rigidly registered for the target image. Then, we calculated their voting weights for label fusion from each combination of JLF's parameters (rpxy, rpz, rsxy, rsz, β). We evaluated the segmentation performances by five validation metrics of the Prostate MR Image Segmentation challenge. Results: As the number of voxels participating in the voting weight calculation and the number of referenced atlases is increased, the overall segmentation performance is gradually improved. The JLF algorithm showed the best results for dice similarity coefficient, 0.8495 ± 0.0392; relative volume difference, 15.2353 ± 17.2350; absolute relative volume difference, 18.8710 ± 13.1546; 95% Hausdorff distance, 7.2366 ± 1.8502; and average boundary distance, 2.2107 ± 0.4972; in parameters of rpxy = 10, rpz = 1, rsxy = 3, rsz = 1, and β = 3. Conclusion: The evaluated results showed the feasibility of the JLF algorithm for automatic segmentation of prostate MRI. This empirical analysis of segmentation results by label fusion allows for the appropriate setting of parameters.

Postmortem analysis of a failed liquid nitrogen-cooled prepolarization coil for SQUID sensor-based ultra-low field magnetic resonance

  • Hwang, Seong-Min;Kim, Kiwoong;Yu, Kwon Kyu;Lee, Seong-Joo;Shim, Jeong Hyun
    • 한국초전도ㆍ저온공학회논문지
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    • 제16권4호
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    • pp.44-48
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    • 2014
  • A liquid nitrogen-cooled prepolarization ($B_p$) coil made for ultra-low field nuclear magnetic resonance and magnetic resonance imaging (ULF-MR) designed to generate 7 mT/A was fabricated. However, with suspected internal insulation failure, the coil was investigated in order to find out the source of the failure. This paper reports detailed build of the failed $B_p$ coil and a number of analysis methods utilized to figure out the source and the mode of failure. The analysis revealed that pyrolytic graphite sheet linings put on either sides of the coil for better thermal conduction acted as an electrical bridge between inner and outer layers of the coil to short out the coil whenever a moderately high voltage was applied across the coil. A simple model circuit simulation corroborated the analysis and further revealed that the failed insulation acted effectively as a damping resistor of $R_{d,eff}=6{\Omega}$ across the coil. This damping resistance produced a 50 ms-long voltage tail after the coil current was ramped down, making the coil not suitable for use in ULF-MR, which requires complete removal of magnetic field from $B_p$ coil within milliseconds.

Molecular Imaging of Arthritis in the Angiogenic Vasculature Using A 123I-Vascular Endothelial Growth Factor Receptor Antibody

  • Kim, Sung-Min;Choi, Na-Eun;Song, Young-Kyu;Cho, Gyung-Goo;Bang, Jeong-Kyu;Kim, Sang-Mi;Lee, Sang-Hoon;Ryu, Eun-Kyoung
    • Bulletin of the Korean Chemical Society
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    • 제33권6호
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    • pp.1890-1894
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    • 2012
  • Vascular endothelial growth factor (VEGF) and its receptor (VEGFR) have been implicated in the pathogenesis of rheumatoid arthritis, which is angiogenesis dependent. Antibody-based molecular imaging improves targeting, and antibody radiolabeling is useful for monitoring biological events $in$ $vivo$ $via$ PET or SPECT. We investigated the potential of molecular imaging to diagnose arthritis with VEGFR-2 $in$ $vivo$. The $^{123}I$-VEGFR-2 antibody was prepared by the iodogen tube method. The radioligand was injected into arthritic mice, and micro SPECT/CT was performed. The arthritic mice were examined by 4.7-T MRI and immunohistochemistry. The $^{123}I$-VEGFR-2 antibody showed high uptake in the arthritic region at 1 h postinjection on SPECT/CT but no uptake in the control animals after radioligand injection. In MR images, the arthritic tissue of the mice was correlated with regions labeled by the $^{123}I$-VEGFR-2 antibody. Immunohistochemical localization showed markedly increased expression of VEGFR-2 in the endothelial cells, fibroblasts, and macrophages of the arthritic mice.

Rapid Progression to Brainstem Encephalitis Caused by Enterovirus 71 Without Throat and Skin Lesions After a One-Day Fever

  • Kyung Min Kim;Soo Yeon Kim;Mi Kyoung Song;Ji Young Kim;Anna Cho;Ji Young Park
    • Pediatric Infection and Vaccine
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    • 제30권2호
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    • pp.91-96
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    • 2023
  • Enterovirus (EV) 71은 무균성 뇌수막염 환자로부터 처음 분리된 이후로 주로 수족구병으로 나타났으며 소아에서 전형적인 피부 발진, 구강 병변 및 발열을 동반한다. 피부 발진은 수포성으로 손과 발에 영향을 미치고 수포가 없는 반구진 양상일 수도 있으며 특히 어린 소아 및 유아에서는 팔꿈치, 무릎 그리고 엉덩이를 침범할 수도 있다. EV 71 감염으로 인한 신경학적 합병증은 매우 드물지만 주로 뇌간 뇌염으로 나타난다. 대근육 운동 발달 지연 이외에 건강했던 30개월 된 남아가 발열, 혼수 증상으로 내원하였고 입원 후 무호흡 및 호흡 정지 증상이 동반되어 뇌척수액 검사 및 뇌 MRI, 뇌파검사를 하였다. 검사 결과 뇌간 뇌염 및 미만성 대뇌 기능 장애가 확인되었고 비인두도말 및 대변 검체에서 EV 71이 검출되었으며 유전자 검사에서 myoclonic epilepsy with ragged red fiber syndrome이 확인되었다. 저자들은 기저미토콘드리아 질환으로 인해 인후 및 피부 발진의 증상 없이 발열 하루 만에 빠르게 진행되는 EV 71 감염으로 인한 뇌간 뇌염 1예를 보고하는 바이다.

병원의 설립형태 및 수익성과 비급여 서비스 가격의 연관성 (Relationship of Hospital Ownership and Profitability with Prices of Non-Covered Services)

  • 김도희;김태현
    • 한국병원경영학회지
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    • 제28권1호
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    • pp.37-51
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    • 2023
  • Purposes: There exist many non-covered services that the National Health Insurance does not cover, and thus, their prices are set by individual health care providers. However, little study has been done to investigate how hospitals set prices for those services. The purpose of this study is to examine the relationship between ownership, profitability, and prices of those services for a sample of general hospitals. Methodology/Approach: Data regarding the prices of major non-covered services (e.g., upper-level hospital room fees, MRI, Da 7inci robot surgery, and LASIK) were obtained from the Health Insurance Review and Assessment Service and the financial information, as well as other characteristics, were derived from the financial reports from the Korea Health Industry Development Institute. Descriptive statistics, t-tests, and multiple linear regression analyses were used to test the relationship between the independent variables and the dependent variables. Findings: Hospitals owned by private universities appeared to have higher prices for non-covered services while regional public hospitals tend to have lower prices. Profitability, measured by operating margin, was not significantly related to the prices. Hospitals that charge higher prices were more likely to be located in the capital area (Seoul, Incheon, and Gyeonggi), and to employ larger number of personnel. Practical Implications: Public hospitals tend to charge lower prices for non-covered services. Relative market power appears to be related to pricing. Further research is needed to investigate whether such a relationship varies over time and its effects on the quality and access.

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MRI Findings in Trigeminal Neuralgia without Neurovascular Compression: Implications of Petrous Ridge and Trigeminal Nerve Angles

  • Hai Zhong;Wenshuang Zhang;Shicheng Sun;Yifan Bie
    • Korean Journal of Radiology
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    • 제23권8호
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    • pp.821-827
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    • 2022
  • Objective: To determine the anatomical characteristics of the petrous ridge and trigeminal nerve in trigeminal neuralgia (TN) without neurovascular compression (NVC). Materials and Methods: From May 2017 to March 2021, 66 patients (49 female and 17 male; mean age ± standard deviation [SD], 56.8 ± 13.3 years) with TN without NVC and 57 controls (46 female and 11 male; 52.0 ± 15.6 years) were enrolled. The angle of the petrous ridge (APR) and angle of the trigeminal nerve (ATN) were measured using magnetic resonance imaging with a high-resolution three-dimensional T2 sequence. Data on the symptomatic side were compared with those on the asymptomatic side in patients and with the mean measurements of the bilateral sides in controls. Receiver operating characteristic (ROC) analysis was conducted to evaluate the performance of APR and ATN in distinguishing TN patients from controls. Results: In TN patients without NVC, the mean ± standard deviation (SD) of APR on the symptomatic side (98.40° ± 19.75°) was significantly smaller than that of the asymptomatic side (105.59° ± 22.45°, p = 0.019) and controls (108.44° ± 15.98°, p = 0.003). The mean ATN ± SD on the symptomatic side (144.41° ± 8.92°) was significantly smaller than that of the asymptomatic side (149.67° ± 8.09°, p = 0.003) and controls (150.45° ± 8.48°, p = 0.001). The area under the ROC curve for distinguishing TN patients from controls was 0.673 (95% confidence interval [CI]: 0.579-0.758) for APR and 0.700 (CI: 0.607-0.782) for ATN. The sensitivity and specificity using the diagnostic cutoff yielding the highest Youden index were 81.8% (54/66) and 49.1% (28/57), respectively, for APR (with a cutoff score of 94.30°) and 65.2% (43/66) and 66.7% (38/57), respectively, for ATN (cutoff score, 148.25°). Conclusion: In patients with TN without NVC, APR and ATN were smaller than those in controls, which may explain the potential cause of TN and provide additional information for diagnosis.

The Short-term Outcomes of Physiotherapy for Patients with Acetabular Labral Tears: An Analysis according to Severity of Injury in Magnetic Resonance Imaging

  • Makoto Kawai;Kenji Tateda;Yuma Ikeda;Ima Kosukegawa;Satoshi Nagoya;Masaki Katayose
    • Hip & pelvis
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    • 제34권1호
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    • pp.45-55
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    • 2022
  • Purpose: The aim of this study was to evaluate the short-term outcome of physiotherapy in patients with acetabular labral tears and to assess the effectiveness of physiotherapy according to the severity of the labral tear. Materials and Methods: Thirty-five patients who underwent physiotherapy for treatment of symptomatic acetabular labral tears were enrolled. We evaluated the severity of the acetabular labral tears, which were classified based on the Czerny classification system using 3-T MRI. Clinical findings of microinstability and extra-articular pathologies of the hip joint were also examined. The International Hip Outcome Tool 12 (iHOT12) was use for evaluation of outcome scores pre- and post-intervention. Results: The mean iHOT12 score showed significant improvement from 44.0 to 73.6 in 4.7 months. Compared with pre-intervention scores, significantly higher post-intervention iHOT12 scores were observed for Czerny stages I and II tears (all P<0.01). However, no significant difference was observed between pre-intervention and post-intervention iHOT12 scores for stage III tears (P=0.061). In addition, seven patients (20.0%) had positive microinstability findings and 22 patients (62.9%) had findings of extra-articular pathologies. Of the 35 patients, eight patients (22.9%) underwent surgical treatment after failure of conservative management; four of these patients had Czerny stage III tears. Conclusion: The iHOT12 score of patients with acetabular labral tears was significantly improved by physiotherapy in the short-term period. Improvement of the clinical score by physiotherapy may be poor in patients with severe acetabular labral tears. Determining the severity of acetabular labral tears can be useful in determining treatment strategies.

급성 신부전 쥐 모델에서 자기 표지된 인간 제대정맥 내피세포의 연속 자기공명영상 (Serial MR Imaging of Magnetically Labeled Humen Umbilical Vein Endothelial Cells in Acute Renal Failure Rat Model)

  • 이선주;이상용;강경표;김원;박성광
    • Investigative Magnetic Resonance Imaging
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    • 제17권3호
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    • pp.181-191
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    • 2013
  • 목적: 급성 신부전 쥐 모델에서 상자성 철 산화물 (superparamagnetic iron oxide(SPIO)로 표지한 인간탯줄혈관내피 세포를 자기공명영상으로 추적할 수 있는지 그 유용성을 평가하고자 하였다. 대상과 방법: 인간탯줄혈관내피 세포를 SPIO와 poly-L-lysine (PLL) 혼합물로 표지 하였다. SPIO 농도에 따라서 이완율, 세포 생존율, 표지 안정성을 SPIO 농도의 변화에 따라 평가하였다. 인간탯줄혈관내피 세포를 급성 신부전 쥐 모델에서 꼬리정맥을 통하여 주사하였다. MR을 이용한 추적 검사는 $T2^*$ 경사에코 MR 영상을 이용하였다. 1, 3, 5, 7일째 추적한 MR 영상 소견을 조직 소견과 서로 견주어 보았다. 결과: SPIO-PLL 혼합물을 표지 한 후 Prussian blue 염색에서 평균 $98.4{\pm}2.4%$ 세포가 양성반응을 보였다. 3일과 5일 후 측정한 이완율은 1일에 비해 큰 차이가 없었다. 인간탯줄혈관내피 세포를 SPIO로 표지 한 후 안정성이 유지됨을 알 수 있었다. 추적 MR 영상에서 급성신부전을 유도한 왼쪽 신장 외곽 신 수질에서 신호강도 소실을 보였으나 오른쪽은 정상이었다. 3, 5, 7일 후 촬영한 영상에서 왼쪽 신 수질에서 보인 신호강도 소실이 점차 사라졌으나 오른쪽 신장에서는 여전히 특별한 변화를 보이지 않았다. 조직학 검사에서도 MR 영상의 신호강도 소실이 Prussian blue 염색을 보인 부분과 일치하였다. 면역화학적 분석에서 신 수질에서 보인 세포들이 인간탯줄혈관내피 세포임을 확인하였다. 결론: MR 영상은 급성 신부전 치료의 한 방법인 세포 치료의 경우 세포 추적 검사에 유용하게 사용될 수 있음을 확인하였다.