Musculoskeletal MRI at 3.0 T and 7.0 T: A comparison of relaxation times and image contrast
Musculoskeletal MRI at 3.0 T and 7.0 T: A comparison of relaxation times and image contrast
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DOI：
10.1016/j.ejrad.2011.09.021
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发表时间：
2013-05-01
影响因子：
3.3
通讯作者：
Gold, Garry E.
中科院分区：
文献类型：
--
作者：
Jordan, Caroline D.;Saranathan, Manojkumar;Gold, Garry E.
目的：测量和比较肌肉骨骼组织在3.0T和7.0T时的松弛时间，为7.0T时的肌肉骨骼方案选择合适的参数。材料和方法：测量5名健康志愿者膝关节在3.0T和7.0T时软骨、肌肉、滑液、骨髓和皮下脂肪的松弛时间T-1和T-2。用自旋回波反转恢复序列测量T-1弛豫时间，共6次反转。使用具有7个回波时间的自旋回波序列测量T-2弛豫时间。T-1和T-2测量技术的准确性在两种磁场强度下的模体中都得到了验证。我们利用测量的弛豫时间来帮助设计7.0T肌肉骨骼方案，该方案保留了我们3.0T方案的良好对比特性，同时在更高的信噪比效率下获得了显著更高的分辨率。结果：所有组织在7.0T时的T-1驰豫时间始终高于3.0T时的测量结果，而在7.0T时的T-2弛豫时间始终低于在3.0T时测量的T-2弛豫时间，测量的弛豫时间被用来帮助开发高分辨率的7.0T序列，其与标准临床3.0T序列的液体到软骨的对比相似：质子密度加权快速自旋回波(FSE)、T-2加权FSE和3D-FSE-Cube。可以根据这些值优化7.0T下肌肉骨骼方案的参数，从而在肌肉骨骼成像中产生更高的分辨率，与标准3.0T临床方案的对比度相似。(C)2011爱思唯尔爱尔兰有限公司。保留所有权利。
Objective: The purpose of this study was to measure and compare the relaxation times of musculoskeletal tissues at 3.0 T and 7.0 T, and to use these measurements to select appropriate parameters for musculoskeletal protocols at 7.0 T.Materials and methods: We measured the T-1 and T-2 relaxation times of cartilage, muscle, synovial fluid, bone marrow and subcutaneous fat at both 3.0 T and 7.0 T in the knees of five healthy volunteers. The T-1 relaxation times were measured using a spin-echo inversion recovery sequence with six inversion times. The T-2 relaxation times were measured using a spin-echo sequence with seven echo times. The accuracy of both the T-1 and T-2 measurement techniques was verified in phantoms at both magnetic field strengths. We used the measured relaxation times to help design 7.0 T musculoskeletal protocols that preserve the favorable contrast characteristics of our 3.0 T protocols, while achieving significantly higher resolution at higher SNR efficiency.Results: The T-1 relaxation times in all tissues at 7.0 T were consistently higher than those measured at 3.0 T, while the T-2 relaxation times at 7.0 T were consistently lower than those measured at 3.0 T. The measured relaxation times were used to help develop high resolution 7.0 T protocols that had similar fluid-to-cartilage contrast to that of the standard clinical 3.0 T protocols for the following sequences: proton-density-weighted fast spin-echo (FSE), T-2-weighted FSE, and 3D-FSE-Cube.Conclusion: The T-1 and T-2 changes were within the expected ranges. Parameters for musculoskeletal protocols at 7.0 T can be optimized based on these values, yielding improved resolution in musculoskeletal imaging with similar contrast to that of standard 3.0 T clinical protocols. (C) 2011 Elsevier Ireland Ltd. All rights reserved.