Advanced Knee ASL Imaging at 7T

7T 先进膝关节 ASL 成像

基本信息

批准号：
10644152
负责人：
Xiufeng Li
金额：
$ 56.15万
依托单位：
UNIVERSITY OF MINNESOTA
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-09-01 至 2023-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10644152
关键词：
Address Adipocytes Adolescent Adult Affect Algorithms Blood Blood capillaries Blood flow Bone Development Bone Marrow Brain Clinical Clinical Research Communities Custom Diagnosis Diagnostic Disease Disease Progression Echo-Planar Imaging Etiology Family Functional disorder Goals Healthcare Image Imaging technology Knee Knee bone Knowledge Lesion Libraries Logistic Regressions Magnetic Resonance Imaging Measures Methodology Methods Modeling Monitor Noise Nomograms Osteochondritis Dissecans Patients Performance Perfusion Physiologic pulse Physiological Physiology Play Population Prognosis RF coil ROC Curve Research Role Safety Signal Transduction Slice Techniques Therapy Evaluation Time Tissue Viability Tissues Treatment Efficacy Uncertainty arterial spin labeling bone bone repair design disease diagnosis efficacy evaluation healing human model imaging modality imaging platform imaging study imaging system improved magnetic field novel prognostic performance research study response skeletal disorder software systems tool treatment response virtual virtual model

项目摘要

Abstract Bone marrow perfusion can provide essential knowledge about bone physiology, improve our understanding of disease etiology and pathophysiology, assist the differentiation between normal and abnormal bone marrow, and assess the response to prescribed therapies. Arterial spin labeling (ASL) magnetic resonance imaging (MRI), as a noninvasive and non-contrast-enhanced approach, is well suited for longitudinal monitoring of disease progression and routine evaluation of therapy response. But ASL imaging of knee epiphyseal bone marrow is challenging because ASL imaging is a low signal-to-noise ratio technique, and the perfusion level is significantly low in epiphyseal yellow bone marrow mainly consisting of fat cells with a sparse network of capillaries. Ultrahigh (≥7T) magnetic field can specifically benefit ASL imaging and overcome these challenges by increasing SNR, prolonging blood and tissue T1, and improving parallel imaging performance. However, the current clinically approved single-transmit MRI system and associated imaging methods are incapable of managing the transmit B1 (B1+) fields needed to realize the promised improvement in imaging quality, reliability, and robustness of 7T while existing RF coils are unable to provide adequate B1+ coverage for optimal ASL imaging. Our long-term goal is to develop and improve UHF imaging methods to better facilitate scientific research and clinical studies to improve the management of skeletal diseases and patient healthcare. The rationale is that the existing technical challenges for UHF imaging, including ASL, can be overcome or mitigated, ultimately to realize UHF potentials with promised benefits and superior imaging ability. The objective of this proposal is to develop and establish an optimized, safe, and efficient parallel transmit (pTx) platform for new pTx-integrated knee ASL imaging methods and explore their clinical potentials in juvenile osteochondritis dissecans (JOCD) patients. We will develop an optimized, safe, and efficient pTx platform for knee ASL imaging by developing a novel 32-channel loop-dipole transmit and receive array knee coil, building a VOP library using 13 human models from the Virtual Family (including morphed models) and evaluating alternative strategies for highly efficient knee ASL imaging, such as utilizing population-matched safety factors for adults and juveniles, respectively. We will develop and optimize pTx-integrated knee ASL imaging methods that will utilize optimized pTx RF pulses. We will also explore the clinical potentials of 7T knee ASL imaging in JOCD in terms of its ability in predicting 6- and 12-month healing status and differentiating patients with and without stable lesions and evaluate the diagnostic and prognostic performance of bone marrow blood flow measures using receiver operating characteristics (ROC) curve analyses. We will also develop a novel multivariate logistic regression model with a new nomogram to predict the healing status after 6, 12 months of nonoperative treatment.

抽象的骨髓灌注可以提供有关骨骼生理学的基本知识，提高我们对疾病病因和病理生理学，有助于正常和异常骨髓之间的分化，并评估对规定疗法的反应。动脉自旋标记（ASL）磁共振成像（MRI）作为一种非侵入性和非对比度增强方法，非常适合纵向监测疾病进展和治疗反应的常规评估。但是膝关节骨的ASL成像骨髓具有挑战性，因为ASL成像是一种低信噪比技术，并且灌注水平为 epiyseal黄色骨髓的明显低，主要由脂肪细胞组成，稀疏网络的网络毛细血管。 Ultrahigh（≥7T）磁场可以特异性地受益于ASL成像并克服这些挑战通过增加SNR，延长血液和组织T1并改善并行成像性能。但是，当前经过临床批准的单经MRI系统和相关的成像方法是无能力的管理要确保成像质量，可靠性， 7T的鲁棒性是在现有的RF线圈时无法为最佳ASL提供足够的B1+覆盖范围成像。我们的长期目标是开发和改善UHF成像方法，以更好地促进科学研究和临床研究，以改善骨骼疾病和患者医疗保健的管理。理由是可以克服或减轻包括ASL在内的UHF成像的现有技术挑战，最终可以通过承诺的好处和出色的成像能力实现UHF潜力。该提议的目的是开发和建立一个新的PTX集成的优化，安全和高效的并行传输（PTX）平台膝盖ASL成像方法并探索其在少年骨软骨炎（JOCD）中的临床潜力患者。我们将通过开发一个优化，安全和高效的PTX平台，以通过开发一个小说32通道环路传输并接收阵列膝盖线圈，使用13个人类模型构建VOP库来自虚拟家族（包括变形的模型），并评估高效膝盖的替代策略 ASL成像，例如分别为成年人和少年使用人群匹配的安全因子。我们将开发并优化了PTX集成的膝关节成像方法，该方法将利用优化的PTX RF脉冲。我们还将探索JOCD中7T膝盖ASL成像的临床潜力，以预测6和6和 12个月的愈合状态和患有和没有稳定病变的患者并评估诊断使用接收器操作特征（ROC）的骨髓血流测量值的预后性能（ROC）曲线分析。我们还将开发一个新型的多元逻辑回归模型，并具有新的列表预测6，12个月的非手术治疗后的愈合状态。