Volumetric cartilage measurements of porcine knee at 1.5-T and 3.0-T MR imaging: Evaluation of precision and accuracy
Volumetric cartilage measurements of porcine knee at 1.5-T and 3.0-T MR imaging: Evaluation of precision and accuracy
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DOI：
10.1148/radiol.2412051330
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发表时间：
2006-11-01
期刊：
影响因子：
19.7
通讯作者：
Link, Thomas M.
中科院分区：
文献类型：
--
作者：
Bauer, Jan S.;Krause, Stefanie J.;Link, Thomas M.
目的：比较3.0-T和1.5-T磁共振（MR）成像的精度和准确性，在量化软骨体积通过使用直接体积测量作为参考standard.Materials和方法：当地动物实验委员会没有要求其批准这项研究。猪膝关节获自屠宰场。这些标本用于优化成像参数，包括脂肪饱和稳态（SPGR）序列、水激发SPGR序列、3.0 T快速自旋回波序列和脂肪饱和SPGR序列的有效信噪比（SNRE）和对比度噪声比（CNRE）。通过使用优化的序列，18个标本在每个序列不到6分钟的时间内成像。对四个样本进行五次重复测量以进行精确度分析。用半自动软件分割软骨，计算体积。成像后，刮下软骨，并通过使用盐水置换法直接测量体积以计算准确度。结果：SNRE和CNRE值，分别是最高的水激发序列在3.0 T（1.81秒（-1/2）和1.27秒（-1/2）），其次是脂肪饱和的SPGR序列（1.52秒（-1/2）和1.07秒（-1/2））。1.5 T下的快速自旋回波序列和脂肪饱和SPGR序列的SNRE较低（分别为1.27 sec（-1/2）和0.59 sec（-1/2））。在股骨MR为基础的体积计算的准确性误差分别为5.0%，3.0%，21%，和16%的水激发，脂肪饱和SPGR，快速自旋回波序列在3.0 T和脂肪饱和SPGR序列在1.5 T，分别。结论：在我们的研究中显示，在3.0 T的MR成像，以更好地量化软骨体积。SNRE和CNRE显著改善，导致确定软骨体积的准确性显著提高。
Purpose: To compare the precision and accuracy of 3.0-T and 1.5-T magnetic resonance (MR) imaging in the quantification of cartilage volume by using direct volumetric measurements as a reference standard.Materials and Methods: The local animal experimentation committee did not require its approval for this study. Porcine knees were obtained from an abattoir. These specimens were used to optimize imaging parameters regarding effective signal-to-noise ratio (SNRE) and contrast-to-noise ratio (CNRE) for a fat-saturated spoiled gradient-recalled acquisition in the steady state (SPGR) sequence, a water excitation SPGR sequence, and a fast spin-echo sequence at 3.0 T and a fat-saturated SPGR sequence at 1.5 T. By using the optimized sequences, 18 specimens were imaged in less than 6 minutes per sequence. A fivefold repetition of measurements of four specimens was performed for precision analysis. Cartilage was segmented by using semiautomatic software to calculate the volume. After imaging, the cartilage was scraped off and the volume was measured directly by using a saline-displacement method to calculate accuracy. Precision and accuracy errors were calculated as the root-mean-squares of the single errors per specimen.Results: SNRE and CNRE values, respectively, were highest for the water excitation sequence at 3.0 T (1.81 sec(-1/2) and 1.27 sec(-1/2)), followed by the fat-saturated SPGR sequence (1.52 sec(-1/2) and 1.07 sec(-1/2)). The fast spin-echo sequence and the fat-saturated SPGR sequence at 1.5 T had lower SNRE (1.27 sec(-1/2) and 0.59 sec(-1/2), respectively). Accuracy error for MR-based volume calculation at the femur was 5.0%, 3.0%, 21%, and 16% for the water excitation, fat-saturated SPGR, and fast spin-echo sequences at 3.0 T and the fat-saturated SPGR sequence at 1.5 T, respectively.Conclusion: MR imaging at 3.0 T was shown in our study to better quantify cartilage volume. SNRE and CNRE were substantially improved, resulting in significantly higher accuracy in determining cartilage volume.