Breda Stephan J, Poot Dirk H J, Papp Dorottya, de Vries Bas A, Kotek Gyula, Krestin Gabriel P, Hernández-Tamames Juan A, de Vos Robert-Jan, Oei Edwin H G
Department of Radiology & Nuclear Medicine, Erasmus MC University Medical Center Rotterdam, Rotterdam, The Netherlands.
Department of Orthopedics and Sports Medicine, Erasmus MC University Medical Center Rotterdam, Rotterdam, The Netherlands.
J Magn Reson Imaging. 2020 Aug;52(2):420-430. doi: 10.1002/jmri.27108. Epub 2020 Feb 28.
Quantitative MRI of patellar tendinopathy (PT) can be challenging due to spatial variation of T * relaxation times.
Prospective.
Sixty-five athletes with PT.
FIELD STRENGTH/SEQUENCE: 3D UTE scans covering the patellar tendon were acquired using a 3.0T scanner and a 16-channel surface coil.
Voxelwise median T * was quantified with monoexponential, fractional-order, and biexponential fitting. We applied two methods for T * analysis: first, a standard approach by analyzing all voxels covering the proximal patellar tendon. Second, within subregions of the patellar tendon, by using thresholds on biexponential fitting parameter percentage short T * (0-30% for mostly long T *, 30-60% for mixed T *, and 60-100% for mostly short T *).
Average test-retest reliability was assessed in three athletes using coefficients-of-variation (CV) and coefficients-of-repeatability (CR).
With standard image analysis, we found a median [interquartile range, IQR] monoexponential T * of 6.43 msec [4.32-8.55] and fractional order T * 4.39 msec [3.06-5.78]. The percentage of short T * components was 52.9% [35.5-69.6]. Subregional monoexponential T * was 13.78 msec [12.11-16.46], 7.65 msec [6.49-8.61], and 3.05 msec [2.52-3.60] and fractional order T * 11.82 msec [10.09-14.44], 5.14 msec [4.25-5.96], and 2.19 msec [1.82-2.64] for 0-30%, 30-60%, and 60-100% short T *, respectively. Biexponential component short T * was 1.693 msec [1.417-2.003] for tissue with mostly short T * and long T * of 15.79 msec [13.47-18.61] for mostly long T *. The average CR (CV) was 2 msec (15%), 2 msec (19%) and 10% (22%) for monoexponential, fractional order and percentage short T *, respectively.
Patellar tendinopathy is characterized by regional variability in binding states of water. Quantitative multicompartment T * analysis in PT can be facilitated using a voxel selection method based on using biexponential fitting parameters.
1 TECHNICAL EFFICACY STAGE: 1 J. Magn. Reson. Imaging 2020;52:420-430.
由于T*弛豫时间的空间变化，髌腱病（PT）的定量MRI可能具有挑战性。
1）比较使用标准方法与在髌腱特定组织区域进行分析的T*定量。2）评估不同方法拟合超短回波时间（UTE）弛豫测量数据的重测可靠性。
前瞻性研究。
65名患有PT的运动员。
场强/序列：使用3.0T扫描仪和16通道表面线圈获取覆盖髌腱的3D UTE扫描图像。
采用单指数、分数阶和双指数拟合对体素中位数T进行定量。我们应用了两种T分析方法：第一，通过分析覆盖髌腱近端的所有体素的标准方法。第二，在髌腱的子区域内，根据双指数拟合参数短T百分比（大部分为长T时为0 - 30%，混合T时为30 - 60%，大部分为短T时为60 - 100%）设置阈值。
使用变异系数（CV）和重复性系数（CR）评估三名运动员的平均重测可靠性。
采用标准图像分析，我们发现单指数T的中位数[四分位间距，IQR]为6.43毫秒[4.32 - 8.55]，分数阶T为4.39毫秒[3.06 - 5.78]。短T成分的百分比为52.9%[35.5 - 69.6]。子区域单指数T分别为13.78毫秒[12.11 - 16.46]、7.65毫秒[6.49 - 8.61]和3.05毫秒[2.52 - 3.60]，分数阶T分别为11.82毫秒[10.09 - 14.44]、5.14毫秒[4.25 - 5.96]和2.19毫秒[1.82 - 2.64]，对应短T为0 - 30%、30 - 60%和60 - 100%。对于大部分为短T的组织，双指数成分短T为1.693毫秒[1.417 - 2.003]，对于大部分为长T的组织，长T为15.79毫秒[13.47 - 18.61]。单指数、分数阶和短T*百分比的平均CR（CV）分别为2毫秒（15%）、2毫秒（19%）和10%（22%）。
髌腱病的特征是水结合状态的区域变异性。使用基于双指数拟合参数的体素选择方法可以促进PT中的定量多区域T*分析。
1 技术效能阶段：1 《磁共振成像杂志》2020年；52:420 - 430。
