• 제목/요약/키워드: dynamic MRI

검색결과 136건 처리시간 0.022초

Hyperpolarized Carbon-13 Magnetic Resonance Imaging: Technical Considerations and Clinical Applications

  • Ying-Chieh Lai;Ching-Yi Hsieh;Yu-Hsiang Juan;Kuan-Ying Lu;Hsien-Ju Lee;Shu-Hang Ng;Yung-Liang Wan;Gigin Lin
    • Korean Journal of Radiology
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    • 제25권5호
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    • pp.459-472
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    • 2024
  • Hyperpolarized (HP) carbon-13 (13C) MRI represents an innovative approach for noninvasive, real-time assessment of dynamic metabolic flux, with potential integration into routine clinical MRI. The use of [1-13C]pyruvate as a probe and its conversion to [1-13C]lactate constitute an extensively explored metabolic pathway. This review comprehensively outlines the establishment of HP 13C-MRI, covering multidisciplinary team collaboration, hardware prerequisites, probe preparation, hyperpolarization techniques, imaging acquisition, and data analysis. This article discusses the clinical applications of HP 13C-MRI across various anatomical domains, including the brain, heart, skeletal muscle, breast, liver, kidney, pancreas, and prostate. Each section highlights the specific applications and findings pertinent to these regions, emphasizing the potential versatility of HP 13C-MRI in diverse clinical contexts. This review serves as a comprehensive update, bridging technical aspects with clinical applications and offering insights into the ongoing advancements in HP 13C-MRI.

승모판 역류 In-Vitro 모델을 활용한 초음파 및 4D flow MRI 기반 혈류 정량화 비교연구 (In-Vitro Model Design of Mitral Valve Regurgitation and Comparative Study of Quantification between PISA and 4D flow MRI)

  • 이주연;권민성;허형규
    • 한국가시화정보학회지
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    • 제22권1호
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    • pp.40-48
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    • 2024
  • This study presents an in-vitro model designed to simulate mitral valve regurgitation, aiming to compare the quantification results between Proximal Isovelocity Surface Area(PISA) and 4D Flow MRI on both fixed and valve annulus tracking(VAT) views. The in-vitro model replicates the dynamic conditions of the mitral valve in a pulsatile environment, utilizing a piston pump set at 60 bpm. Through systematic experiments and analysis, the study evaluates the accuracy and effectiveness of PISA and 4D Flow MRI in assessing regurgitation severity, considering both fixed and valve annulus tracking. The displacement length measured in echo closely resembled that of optical measurements, making it advantageous for structural analysis. VAT-4D flow MRI exhibited the smallest deviation from actual flow rate values, establishing it as most accurate method for quantitative regurgitation assessment.

MRI-guided Wire Localization Open Biopsy is Safe and Effective for Suspicious Cancer on Breast MRI

  • Wang, Hai-Yi;Zhao, Yu-Nian;Wu, Jian-Zhong;Wang, Zheng;Tang, Jing-Hai
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권5호
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    • pp.1715-1718
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    • 2015
  • Background: Magnetic resonance imaging of breast, reported to be a high sensitivity of 94% to 100%, is the most sensitive method for detection of breast cancer. The purpose of this study was to investigate our clinical experience in MRI-guided breast lesion wire localization in Chinese women. Materials and Methods: A total of 44 patients with 46 lesions undergoing MRI-guided breast lesion localization were prospectively entered into this study between November 2013 and September 2014. Samples were collected using a 1.5-T magnet with a special MR biopsy positioning frame device. We evaluated clinical lesion characteristics on pre-biopsy MRI, pathologic results, and dynamic curve type baseline analysis. Results: Of the total of 46 wire localization excision biopsied lesions carried out in 44 female patients, pathology revealed fourteen malignancies (14/46, 30.4%) and thirty-two benign lesions (32/46, 69.6%). All lesions were successfully localized followed by excision biopsy and assessed for morphologic features highly suggestive of malignancy according to the American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) category of MRI (C4a=18, C4b=17, C4c=8,C5=3). Of 46 lesions, 37 were masses and 9 were non-mass enhancement lesions. Thirty-two lesions showed a continuous kinetics curve, 11 were plateau and 3 were washout. Conclusions: Our study showed success in MRI-guided breast lesion wire localization with a satisfactory cancer diagnosis rate of 30.4%. MRI-guided wire localization breast lesion open biopsy is a safe and effective tool for the workup of suspicious lesions seen on breast MRI alone without major complications. This may contribute to increasing the diagnosis rate of early breast cancer and improve the prognosis in Chinese women.

Comparison between Computer Tomography and Magnetic Resonance Imaging in the Diagnosis of Small Hepatocellular Carcinoma

  • Lertpipopmetha, Korn;Tubtawee, Teeravut;Piratvisuth, Teerha;Chamroonkul, Naichaya
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권11호
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    • pp.4805-4811
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    • 2016
  • Background: Hepatocellular carcinomas (HCCs) less than 2 cm in diameter generally demonstrate a good outcome after curative therapy. However, the diagnosis of small HCC can be problematic and requires one or more dynamic imaging modalities. This study aimed to compare the sensitivity and agreement between CT and MRI for the diagnosis of small HCCs. Methods: CT and/or MRI scans of HCCs (1-2 cm) diagnosed by histopathology or typical vascular pattern according to the 2005 AASLD criteria were blindly reviewed by an abdominal radiologist. The reports were defined as conclusive/typical when arterial enhancement and washout during the portal/delayed phases were observed and as inconclusive when typical vascular patterns were not observed. The sensitivity and Cohen's kappa (k) for agreement were calculated. Results: In 27 patients, 27 HCC nodules (1-2 cm) were included. Diagnosis with a single-imaging modality (CT or MRI) was 81 % versus 48 % (p = 0.01). The CT sensitivity was significantly higher than MRI (78 % versus 52 %, p = 0.04). Among 27 nodules that underwent both CT and MRI, a discordance in typical enhancement patterns was found (k = 0.319, p = 0.05). In cases with inconclusive CT results, MRI gave only an additional 3.7 % sensitivity to reach a diagnosis. In contrast, further CT imaging following inconclusive MRI results gave an additional 29.6 % sensitivity.Conclusions: A single typical imaging modality is sufficient to diagnose small HCCs. Compared with MRI, multiphasic CT has a higher sensitivity. The limitations of MRI could be explained by the greater need for patient cooperation and the types of MRI contrast agent.

Monitoring Cerebral Perfusion Changes Using Arterial Spin-Labeling Perfusion MRI after Indirect Revascularization in Children with Moyamoya Disease

  • Seul Bi Lee;Seunghyun Lee;Yeon Jin Cho;Young Hun Choi;Jung-Eun Cheon;Woo Sun Kim
    • Korean Journal of Radiology
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    • 제22권9호
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    • pp.1537-1546
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    • 2021
  • Objective: To assess the role of arterial spin-labeling (ASL) perfusion MRI in identifying cerebral perfusion changes after indirect revascularization in children with moyamoya disease. Materials and Methods: We included pre- and postoperative perfusion MRI data of 30 children with moyamoya disease (13 boys and 17 girls; mean age ± standard deviation, 6.3± 3.0 years) who underwent indirect revascularization between June 2016 and August 2017. Relative cerebral blood flow (rCBF) and qualitative perfusion scores for arterial transit time (ATT) effects were evaluated in the middle cerebral artery (MCA) territory on ASL perfusion MRI. The rCBF and relative time-to-peak (rTTP) values were also measured using dynamic susceptibility contrast (DSC) perfusion MRI. Each perfusion change on ASL and DSC perfusion MRI was analyzed using the paired t test. We analyzed the correlation between perfusion changes on ASL and DSC images using Spearman's correlation coefficient. Results: The ASL rCBF values improved at both the ganglionic and supraganglionic levels of the MCA territory after surgery (p = 0.040 and p = 0.003, respectively). The ATT perfusion scores also improved at both levels (p < 0.001 and p < 0.001, respectively). The rCBF and rTTP values on DSC MRI showed significant improvement at both levels of the MCA territory of the operated side (all p < 0.05). There was no significant correlation between the improvements in rCBF values on the two perfusion images (r = 0.195, p = 0.303); however, there was a correlation between the change in perfusion scores on ASL and rTTP on DSC MRI (r = 0.701, p < 0.001). Conclusion: Recognizing the effects of ATT on ASL perfusion MRI may help monitor cerebral perfusion changes and complement quantitative rCBF assessment using ASL perfusion MRI in patients with moyamoya disease after indirect revascularization.

Patellofemoral Instability - Diagnostic approach -

  • 경희수
    • 대한관절경학회:학술대회논문집
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    • 대한관절경학회 2008년도 춘계 공동 학술대회
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    • pp.98-111
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    • 2008
  • 슬개대퇴 불안정성의 진단은 정확한 해부학적 지식을 바탕으로 역동적인(dynamic) 기전을 이해하여야 한다. 슬개골의 저명한 탈구는 쉽게 진단되지만, 경미한 외상으로 슬개골이 탈구되어 정복된 후에는 올바른 진찰(dynamic study)없이 방사선 검사(static study)으로 진단을 놓치는 경우가 많다. 그러므로 병력, 이학적 진찰, 방사선 검사, CT, MRI 그리고 관절경 검사까지 다양하게 필요할 수 있다.

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자기공명영상 동적검사 시 조영제 역류방지용 밸브의 유용성 (Usefulness of Reverse Flow Prevention Valves for Back-flow Prevention of Gadolinium Based Contrast Agent in Dynamic Examination of Magnetic Resonance Imaging)

  • 손순룡
    • 한국콘텐츠학회논문지
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    • 제20권6호
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    • pp.439-444
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    • 2020
  • 이 연구는 자기공명영상검사 시 조영제 주입용으로 사용되는 자동주입기에서 조영제 역류에 의한 생리식염수의 오탁 현상을 방지할 수 있는 대안을 모색하고자 하였다. 연구방법은 실린지 내에서 조영제 역류를 차단할 대안으로 밸브를 자체 제작한 다음, 임상적용의 유용성을 알아보기 위해 생리식염수의 상태를 세 그룹으로 나누고 조영제 주입을 실험하여 각각 채취한 생리식염수의 지방소거 T1 강조영상으로 신호강도를 비교하였다. 연구결과, 그룹 1의 조영제 주입 전 생리식염수와 그룹 3의 역류방지용 밸브를 적용한 조영제 주입 후 생리식염수가 통계적으로 유의한 차이가 없었다(p>0.05). 이는 자체 제작한 역류방지용 밸브가 조영제 주입 시 생리식염수로 역류하는 조영제를 완벽히 차단한 것으로 분석된다. 결론적으로 조영제 자동주입기를 활용한 자기공명영상 동적검사 시 본 연구에서 제시한 역류방지밸브를 적용한다면 조영제 역류로 인한 생리식염수의 오탁 현상을 예방할 수 있으리라 본다.