• 제목/요약/키워드: Contrast-enhanced magnetic resonance imaging

검색결과 203건 처리시간 0.024초

Targeting a Safe Entry Point for C2 Pedicle Screw Fixation in Patients with Atlantoaxial Instability

  • Chun, Hyoung-Joon;Bak, Koang-Hum
    • Journal of Korean Neurosurgical Society
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    • 제49권6호
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    • pp.351-354
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    • 2011
  • Objective : This investigation was conducted to evaluate a new, safe entry point for the C2 pedicle screw, determined using the anatomical landmarks of the C2 lateral mass, the lamina, and the isthmus of the pars interarticularis. Methods : Fifteen patients underwent bilateral C1 lateral mass-C2 pedicle screw fixation, combined with posterior wiring. The C2 pedicle screw was inserted at the entry point determined using the following method : 4 mm lateral to and 4 mm inferior to the transitional point (from the superior end line of the lamina to the isthmus of the pars interarticularis). After a small hole was made with a high-speed drill, the taper was inserted with a 30 degree convergence in the cephalad direction. Other surgical procedures were performed according to Harm's description. Preoperatively, careful evaluation was performed with a cervical X-ray for C1-C2 alignment, magnetic resonance imaging for spinal cord and ligamentous structures, and a contrast-enhanced 3-dimensional computed tomogram (3-D CT) for bony anatomy and the course of the vertebral artery. A 3-D CT was checked postoperatively to evaluate screw placement Results : Bone fusion was achieved in all 15 patients (100%) without screw violation into the spinal canal, vertebral artery injury, or hardware failure. Occipital neuralgia developed in one patient, but this subsided after a C2 ganglion block. Conclusion : C2 transpedicular screw fixation can be easily and safely performed using the entry point of the present study. However, careful preoperative radiographic evaluation, regardless of methods, is mandatory.

Non-infected and Infected Bronchogenic Cyst: The Correlation of Image Findings with Cyst Content

  • Jeon, Hong Gil;Park, Ju Hwan;Park, Hye Min;Kwon, Woon Jung;Cha, Hee Jeong;Lee, Young Jik;Park, Chang Ryul;Jegal, Yangjin;Ahn, Jong-Joon;Ra, Seung Won
    • Tuberculosis and Respiratory Diseases
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    • 제76권2호
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    • pp.88-92
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    • 2014
  • We hereby report a case on bronchogenic cyst which is initially non-infected, then becomes infected after bronchoscopic ultrasound (US)-guided transesophageal fine-needle aspiration (FNA). The non-infected bronchogenic cyst appears to be filled with relatively echogenic materials on US, and the aspirate is a whitish jelly-like fluid. Upon contrast-enhanced MRI of the infected bronchogenic cyst, a T1-weighted image shows low signal intensity and a T2-weighted image shows high signal intensity, with no enhancements of the cyst contents, but enhancements of the thickened cystic wall. The patient then undergo video-assisted thoracic surgery 14 days after the FNA. The cystic mass is known to be completely removed, and the aspirate is yellowish and purulent. To understand the image findings that pertain to the gross appearance of the cyst contents will help to diagnose bronchogenic cysts in the future.

Boundary-Aware Dual Attention Guided Liver Segment Segmentation Model

  • Jia, Xibin;Qian, Chen;Yang, Zhenghan;Xu, Hui;Han, Xianjun;Ren, Hao;Wu, Xinru;Ma, Boyang;Yang, Dawei;Min, Hong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제16권1호
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    • pp.16-37
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    • 2022
  • Accurate liver segment segmentation based on radiological images is indispensable for the preoperative analysis of liver tumor resection surgery. However, most of the existing segmentation methods are not feasible to be used directly for this task due to the challenge of exact edge prediction with some tiny and slender vessels as its clinical segmentation criterion. To address this problem, we propose a novel deep learning based segmentation model, called Boundary-Aware Dual Attention Liver Segment Segmentation Model (BADA). This model can improve the segmentation accuracy of liver segments with enhancing the edges including the vessels serving as segment boundaries. In our model, the dual gated attention is proposed, which composes of a spatial attention module and a semantic attention module. The spatial attention module enhances the weights of key edge regions by concerning about the salient intensity changes, while the semantic attention amplifies the contribution of filters that can extract more discriminative feature information by weighting the significant convolution channels. Simultaneously, we build a dataset of liver segments including 59 clinic cases with dynamically contrast enhanced MRI(Magnetic Resonance Imaging) of portal vein stage, which annotated by several professional radiologists. Comparing with several state-of-the-art methods and baseline segmentation methods, we achieve the best results on this clinic liver segment segmentation dataset, where Mean Dice, Mean Sensitivity and Mean Positive Predicted Value reach 89.01%, 87.71% and 90.67%, respectively.

당뇨발 치료 동향: 대한족부족관절학회 회원 설문조사 분석 (Current Trends in the Treatment of Diabetic Foot: Analysis of the Korean Foot and Ankle Society (KFAS) Member Survey)

  • 원성훈;민태홍;천동일;배서영;2021 대한족부족관절학회 학술위원회
    • 대한족부족관절학회지
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    • 제26권1호
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    • pp.30-39
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    • 2022
  • Purpose: This study aimed to report the current trends in the management of diabetic foot over the last few decades through a survey of the Korean Foot and Ankle Society (KFAS) members. Materials and Methods: A web-based questionnaire containing 40 questions was sent to all KFAS members in September 2021. The questions were mainly related to the demographics of patients with diabetic foot, diagnostic tools, and multidisciplinary treatment. Answers with a prevalence of ≥50% of respondents were considered a tendency. Results: Seventy-eight of the 550 members (14.2%) responded to the survey. The most common demographic factors of diabetic foot patients were male dominance with a high percentage in the 60- to 70-year-old. Although the need for multidisciplinary treatment is highly recognized in the treatment of diabetic foot patients, the actual implementation rate is about 39%. The contrast-enhanced magnetic resonance imaging (88.5%) was reported to be the most used tool for the diagnosis of osteomyelitis of the diabetic foot. It was reported that the use of antibiotics was started empirically and then changed based on bacterial culture tests in 82.1% of patients. Simple wound dressing and antibiotic treatment were most frequently reported for mild ulcers. Conclusion: This study provides updated information on the current trends in the management of a diabetic foot in Korea. Both consensus and variations in the approach to patients with diabetic foot were identified by this survey study. Further efforts are required for better access to a multidisciplinary approach, such as appropriate insurance payment policies and patient education.

Isolated unilateral temporalis muscle hypertrophy of unknown etiology: a case report and literature review

  • Jun Ho Choi;Seung Yeon Choi;Jae Ha Hwang;Kwang Seog Kim;Sam Yong Lee
    • 대한두개안면성형외과학회지
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    • 제24권6호
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    • pp.278-283
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    • 2023
  • The initial instance of isolated unilateral temporalis muscle hypertrophy (IUTMH) was reported in 1990. Since then, only few cases have been documented. The cause of this condition remains ambiguous; however, it is presumed to be linked to compensatory and stress-induced hypertrophy. We introduce a rare case of the diagnosis and treatment of IUTMH. A 39-year-old woman presented with a steadily enlarging pain-free swelling on the left side of her face, first noticed a month ago. Apart from a hyperthyroidism medication regimen her medical history was unremarkable. She had no history of temporomandibular joint disease, bruxism, surgery, or trauma. However, she complained of having been under substantial stress lately. Contrast-enhanced magnetic resonance imaging revealed asymmetric temporalis muscle hypertrophy. The treatment plan consisted of administering type A botulinum toxin injections into left temporalis muscle, supplemented by lifestyle changes and relaxation techniques. At a follow-up visit 9 months after the injections, the muscle contour was normalized both in physical and in radiologic examinations. While further supportive evidence is needed, it can be anticipated that cosmetic treatment with botulinum toxin, rather than surgical interventions, will become the standard treatment of IUTMH.

두경부 MALT 림프종 환자에서 나타난 국소적 종괴 주위 아밀로이증의 전산화단층촬영 및 자기공명영상 소견: 증례 보고 (CT and MRI Features of Localized Peritumoral Amyloidosis in a Patient with Head and Neck Mucosa-Associated Lymphoid Tissue Lymphoma: A Case Report)

  • 김한준;홍현숙;김지윤
    • 대한영상의학회지
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    • 제82권5호
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    • pp.1334-1340
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    • 2021
  • 아밀로이드증과 비호지킨림프종과의 연관관계는 이전의 연구들에서 보고된 바 있다. 림프종과 아밀로이드증과의 연관관계는 두 개의 구분되는 범주로 나뉘는데 림프종 연관 전신성 아밀로이드증과 종괴 주위 아밀로이드증이다. 저자들은 두경부 MALT 림프종 환자에서 발생한 국소적 종괴 주위 아밀로이드증의 드문 증례를 보고하고자 한다. 전산화단층촬영에서 병변은 연조직음영을 보이는 무정형석회화를 동반한 불규칙한 모양의 종괴였으며, 조영증강 시 불균일한 조영증강을 보였다. 자기공명영상에서는 종괴가 T1 강조영상과 T2 강조영상에서 모두 불균일한 낮은 신호 강도를 보였다. 종괴는 강한 조영증강을 보였으며, 내부에는 여러 개의 조영증강되지 않는 부분들을 포함하고 있었다. 림프종 환자에서 치료 전 영상검사에서 발견된 석회화들은 종괴 주위 아밀로이드증과 같은 동반된 다른 이차성 병변을 시사하는 소견이 될 수 있을 것이다.

초기 간암 선별 검사로서 단축 자기공명영상 검사의 진단능: 고식적 역동학적 자기공명영상검사와의 비교 (Diagnostic Performance of Simulated Abbreviated MRI for Early-Stage Hepatocellular Carcinoma Screening: A Comparison to Conventional Dynamic Contrast-Enhanced MRI)

  • 임은솔;김성모;신상수;허숙희;이종은;정용연
    • 대한영상의학회지
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    • 제82권5호
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    • pp.1218-1230
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    • 2021
  • 목적 고위험 환자에서 초기 간암 선별 검사로써 단축 자기공명영상 검사의 환자별 진단능을 기존의 고식적 간 자기공명영상검사와 비교하고자 한다. 대상과 방법 간암 고위험군에서 간 자기공명영상 검사를 시행 받은 총 201명의 환자에 대해 연구를 시행하였다. 단축 자기공명영상 검사 군의 프로토콜은 T2 강조영상, 담도기 T1 강조영상, 확산강조영상 등으로 구성되며, 두 명의 영상의학과 의사가 각각의 환자에 대해 후향적으로 단축 자기공명영상검사 군 및 고식적 자기공명영상검사 군, 두 군의 영상을 독립적으로 평가하였다. 두 연구자 간 일관성은 Cohen's kappa 값을 이용하여 비교하였다. 복합적인 참조표준을 이용하여 두 군에서 각각 진단능을 평가하여 비교하였다. 결과 79 명의 환자에서 총 93개의 간암이 발견되었다. 두 연구자 간 일관성은 두 군에서 모두 매우 양호하였다(κ = 0.839, 0.948). 단축 자기공명영상검사 군에서 민감도 및 음성예측도는 각각 94.9% 및 96.4%였으며, 이는 고식적 자기공명영상검사 군과 큰 차이를 보이지 않았다(96.2%, 97.5%). 결론 단축 자기공명영상검사는 고식적 자기공명영상검사에 비교하여 임상적으로 허용 가능한 민감도와 음성예측도를 갖는다. 따라서 간암 고위험군 환자에서 간암 선별검사로써 새로운 대안이 될 수 있을 것이다.

요추 신경근 평가를 위한 1.5T MR의 단일 방향 경사자장을 사용한 확산강조 자기공명신경조영 (Diffusion-Weighted MR Neurography with Unidirectional Motion-Probing Gradient to Evaluate Lumbar Nerve Roots at 1.5T MR)

  • 윤나연;하두회;이상민;최혜정
    • 대한영상의학회지
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    • 제85권3호
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    • pp.607-617
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    • 2024
  • 목적 최근 확산강조 자기공명신경조영(diffusion-weighted MR neurography; 이하 DW MRN)이 신경근 평가에 도움이 된다고 보고되었다. 본 연구는 1.5T MR에서 단일방향 경사자장을 사용한 DW MRN의 요추 신경근 평가의 유용성을 확인하고자 한다. 대상과 방법 앞뒤 방향 경사자장의 DW MRN을 포함한 64요추 MR을 후향적으로 분석했다. 제3 요추에서 제1 천추까지 총 512개 요추 신경근의 변화를 T2 강조영상, 조영증강 T1 강조영상, 그리고 DW MRN에서 평가하고 일치도와 상관관계 분석을 했다. 결과 T2 강조영상에서 78개의 신경근 압박이 있었고, 조영증강 T1 강조영상에서 52개 신경근이 조영증강되었다. DW MRN에서 67개 신경근의 부종과 고신호강도가 있었다. 조영증강 T1 강조영상과 DW MRN 모두 신경근의 변화가 나타난 경우는 42개였다. DW MRN과 조영증강 T1 강조영상, T2 강조영상 간에 중간 또는 상당한 일치도와 양의 상관관계를 보였다(κ = 0.59-0.65, ρ = 0.600-0.653). 결론 앞뒤 단일방향을 사용한 DW MRN은 척추 신경근의 변화 평가에 도움이 되며, 가돌리늄 조영증강을 대체 또는 보완하는 역할을 할 수 있을 것이다.

Measurement of Apparent Diffusion Coefficient Values from Diffusion-Weighted MRI: A Comparison of Manual and Semiautomatic Segmentation Methods

  • Kim, Seong Ho;Choi, Seung Hong;Yoon, Tae Jin;Kim, Tae Min;Lee, Se-Hoon;Park, Chul-Kee;Kim, Ji-Hoon;Sohn, Chul-Ho;Park, Sung-Hye;Kim, Il Han
    • Investigative Magnetic Resonance Imaging
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    • 제19권2호
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    • pp.88-98
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    • 2015
  • Purpose: To compare the interobserver and intraobserver reliability of mean apparent diffusion coefficient (ADC) values using contrast-enhanced (CE) T1 weighted image (WI) and T2WI as structural images between manual and semiautomatic segmentation methods. Materials and Methods: Between January 2011 and May 2013, 28 patients who underwent brain MR with diffusion weighted image (DWI) and were pathologically confirmed as having glioblastoma participated in our study. The ADC values were measured twice in manual and semiautomatic segmentation methods using CE-T1WI and T2WI as structural images to obtain interobserver and intraobserver reliability. Moreover, intraobserver reliabilities of the different segmentation methods were assessed after subgrouping of the patients based on the MR findings. Results: Interobserver and intraobserver reliabilities were high in both manual and semiautomatic segmentation methods on CE-T1WI-based evaluation, while interobserver reliability on T2WI-based evaluation was not high enough to be used in a clinical context. The intraobserver reliability was particularly lower with the T2WI-based semiautomatic segmentation method in the subgroups with involved $lobes{\leq}2$, with partially demarcated tumor borders, poorly demarcated inner margins of the necrotic portion, and with perilesional edema. Conclusion: Both the manual and semiautomatic segmentation methods on CE-T1WI-based evaluation were clinically acceptable in the measurement of mean ADC values with high interobserver and intraobserver reliabilities.

What Effects Does Necrotic Area of Contrast-Enhanced MRI in Osteoporotic Vertebral Fracture Have on Further Compression and Clinical Outcome?

  • Lee, Ja Myoung;Lee, Young Seok;Kim, Young Baeg;Park, Seung Won;Kang, Dong Ho;Lee, Shin Heon
    • Journal of Korean Neurosurgical Society
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    • 제60권2호
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    • pp.181-188
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    • 2017
  • Objective : The objective of this study was to analyze the correlation between further compression and necrotic area in osteoporotic vertebral fracture (OVF) patients with contrast-enhanced magnetic resonance imaging (CEMRI). In addition, we investigated the radiological and clinical outcome according to the range of the necrotic area. Methods : Between 2012 and 2014, the study subjects were 82 OVF patients who did not undergo vertebroplasty or surgical treatment. The fracture areas examined on CEMRI at admission were defined as edematous if enhancement was seen and as necrotic if no enhancement was seen. The correlation between further compression and the necrotic and edematous areas of CEMRI, age, and bone mineral density was examined. Also, necrotic areas were classified into those with less than 25% (non-necrosis group) and those with more than 25% (necrosis group) according to the percentages of the entire vertebral body. For both groups, further compression and the changes in wedge and kyphotic angles were examined at admission and at 1 week, 3 months, and 6 months after admission, while the clinical outcomes were compared using the visual analog scale (VAS) and Eastern Cooperative Oncology Group (ECOG) performance status grade. Results : Further compression was $14.78{\pm}11.11%$ at 1 month and $21.75{\pm}14.43%$ at 6 months. There was a very strong correlation between the necrotic lesion of CEMRI and further compression (r=0.690, p<0.001). The compression of the necrosis group was $33.52{\pm}12.96%$, which was higher than that of the non-necrosis group, $14.96{\pm}10.34%$ (p<0.005). Also, there was a statistically significantly higher number of intervertebral cleft development and surgical treatments being performed in the necrosis group than in the non-necrosis group (p<0.005). Moreover, there was a statistical difference in the decrease in the height of the vertebral body, and an increase was observed in the kyphotic change of wedge angle progression. There was also a difference in the VAS and ECOG performance scales. Conclusion : The necrotic area of CEMRI in OVF had a strong correlation with further compression over time. In addition, with increasing necrosis, intervertebral clefts occurred more frequently, which induced kyphotic changes and resulted in poor clinical outcomes. Therefore, identifying necrotic areas by performing CEMRI on OVF patients would be helpful in determining their prognosis and treatment course.