OBJECTIVE As biologic augmentation methods emerge, objective measures of soft tissues are necessary for developmental study. The purpose of this study was to develop a quantitative MRI mapping protocol for the ACL. The objectives were (1) to provide age-based T2 relaxation, T2* relaxation, and volume values in healthy individuals, (2) to establish the intra-rater and inter-rater reliability of ACL mapping, and (3) to determine whether 3-T or 7-T MRI is more appropriate for future clinical trials. MATERIALS AND METHODS Thirty healthy participants, aged 18-62, asymptomatic for knee pathology and without history of knee injury underwent both a 3-T and 7-T MRI. Manual image mapping of the anterior cruciate ligament was performed by two observers and processed to obtain T2, T2*, and volume values. Analysis of variance and two-way random effects model were used to calculate statistical significance and intraclass correlation coefficients. RESULTS Across all participants, 3-T and 7-T mean T2, T2* and volume values were 37.1 ± 7.9 and 39.7 ± 6.2 ms (p = 0.124), 10.9 ± 1.3 and 10.9 ± 0.9 ms (p = 0.981), and 2380 ± 602 and 2484 ± 736 mm3 (p = 0.551), respectively. The T2, T2*, and volume did not vary between age cohorts (p > 0.05). Excellent inter-rater and intra-rater reliability regarding T2 and T2* values was found. While ACL volume exhibited good inter-rater reliability and excellent intra-rater reliability. CONCLUSIONS T2 relaxation values and ACL volume do not vary with age and therefore can be used as a quantifiable, non-invasive method to assess ACL graft maturation. 7-T MRI analysis was not superior to 3-T MRI analysis, suggesting that 3-T MRI is practical and capable for future comparative studies.

中文翻译：

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3-T MRI映射是一种定量评估前交叉韧带的有效体内方法：评估者的信度和跨年龄的比较。

目的随着生物增强方法的出现，软组织的客观测量对于发育研究是必要的。这项研究的目的是为ACL开发定量MRI映射方案。目标是（1）提供健康个体中基于年龄的T2松弛，T2 *松弛和体积值；（2）建立ACL映射的评分者内和评分者间可靠性；以及（3）确定是否3-T或7-T MRI更适合将来的临床试验。材料与方法30名健康参与者，年龄18-62岁，无膝关节病理症状且无膝关节损伤史，均接受了3T和7T MRI检查。两名观察员对前交叉韧带进行了手动成像，并进行了处理，以获得T2，T2 *和体积值。使用方差分析和双向随机效应模型来计算统计显着性和类内相关系数。结果在所有参与者中，3-T和7-T的平均T2，T2 *和体积值分别为37.1±7.9和39.7±6.2 ms（p = 0.124），10.9±1.3和10.9±0.9 ms（p = 0.981），以及分别为2380±602和2484±736 mm3（p = 0.551）。在不同年龄组之间，T2，T2 *和体积没有变化（p> 0.05）。发现有关T2和T2 *值的出色的评估者间和评估者内可靠性。而ACL量显示出良好的评估者间可靠性和出色的评估者内可靠性。结论T2弛豫值和ACL体积不会随年龄变化，因此可以用作评估ACL移植物成熟度的一种可量化的非侵入性方法。7-T MRI分析不优于3-T MRI分析，