Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
Department of Radiology, VA San Diego Healthcare System, San Diego, CA.
Invest Radiol. 2019 Jun;54(6):349-355. doi: 10.1097/RLI.0000000000000547.
In human menisci, we aimed to investigate whether calcium pyrophosphate crystal deposition (CPPD) affects biomechanical and quantitative MR properties, and their zonal distribution.
From 9 cadaveric knees, sectioned triangular meniscus pieces were harvested. Samples were classified into "normal" or "CPPD" groups based upon visual inspection. Micro computed tomography scan verified CPPD. Using magnetic resonance imaging, ultrashort echo time (UTE) T2* and spin echo (SE) T2, quantitative values in 3 zones (red, red-white, and white) were determined. Using biomechanical test, indentation forces in the same zones were determined. Effects of CPPD and meniscal zone on indentation force and quantitative MR values were compared.
On UTE MRI scans, CPPD-affected menisci exhibited punctate dark regions, found mostly (92%) in avascular white and red-white zones. Indentation forces were significantly higher for CPPD samples in the red-white (all P < 0.02) and white (all P < 0.004) zones but not in the vascular red zone (all P > 0.2). Similarly, UTE T2* red zone values were similar between both groups (6.6 milliseconds, P = 0.8), whereas in the red-white and white zones, CPPD samples had significantly lower values (5.1 milliseconds, P = 0.005 to 0.007). In contrast, SE T2 values showed no difference with CPPD (P = 0.12 to 0.16). UTE T2*, but not SE T2, correlated significantly with indentation force (R = -0.29, P = 0.009).
Dark CPP deposits were detectable on UTE images featuring high signal intensity from surrounding meniscal tissue. Preliminary results indicate that CPP deposits were almost exclusively found in the avascular zones. Compared with normal, CPPD menisci featured higher indentation stiffness and lower UTE T2* values in the affected zones.
在人类半月板中，我们旨在研究焦磷酸钙晶体沉积 (CPPD) 是否会影响生物力学和定量磁共振 (MR) 属性及其分区分布。
从 9 个尸体膝关节中采集了三角形半月板切片。根据肉眼观察，将样本分为“正常”或“CPPD”组。微计算机断层扫描 (micro CT) 扫描证实 CPPD 的存在。使用磁共振成像 (MRI)，超短回波时间 (UTE) T2* 和自旋回波 (SE) T2，确定 3 个区（红区、红白区和白区）的定量值。使用生物力学测试，确定相同区的压痕力。比较 CPPD 和半月板区对压痕力和定量 MR 值的影响。
在 UTE MRI 扫描中，CPPD 影响的半月板显示出点状暗区，这些暗区主要（92%）存在于无血管的白区和红白区。在红白区（所有 P < 0.02）和白区（所有 P < 0.004），CPPD 样本的压痕力明显更高，但在有血管的红区（所有 P > 0.2）则不然。同样，两组 UTE T2红区值相似（约 6.6 毫秒，P = 0.8），而在红白区和白区，CPPD 样本的 UTE T2值明显较低（约 5.1 毫秒，P = 0.005 至 0.007）。相比之下，SE T2 值与 CPPD 无差异（P = 0.12 至 0.16）。UTE T2*与压痕力显著相关（R = -0.29，P = 0.009），但 SE T2 则不然。
UTE 图像上可以检测到 CPP 沉积物的暗区，这些暗区表现为周围半月板组织的高信号强度。初步结果表明，CPP 沉积物几乎仅存在于无血管区。与正常半月板相比，CPPD 半月板在受影响区的压痕刚度更高，UTE T2*值更低。
