Goebel Jean-Christophe, Bolbos Radu, Pinzano Astrid, Schaeffer Mathilde, Rengle Adrian, Galois Laurent, Etienne Stéphanie, Netter Patrick, Loeuille Damien, Beuf Olivier, Gillet Pierre
UMR 7561 CNRS - Nancy Université, Vandoeuvre lès Nancy, France.
Biomed Mater Eng. 2008;18(4-5):247-52.
to assess reliability and reproducibility of quantitative MRI (7 T) in assessing rat femoro-tibial cartilage volume.
5 healthy rat knees were scanned in vivo using a 7 T experimental imager. Sagittal high resolution 3D Gradient Echo with fat suppression sequences were performed with a dedicated home-made 2-elements array coil. 3D MRI sets were used to perform manual segmentation of the 3 cartilage compartments (femoral groove, medial and lateral tibial plateaus) by using a tactile screen. To evaluate inter- and intra-observer reproducibilities, the segmentation procedure was done blindly by two trained observers. One observer repeated the operation twice, with a period of 10 months between both readings.
the mean duration to manually segment all the slices covering the cartilaginous joint was 4 hours. On the one hand, the inter-observer root mean square of coefficients of variation was 9.1%, 6.2%, 9.6% for the femoral, medial and lateral tibial compartments respectively. On the other hand, the intra-observer reproducibility was 2.1%, 3.2%, 2.5% for these cartilage compartments cited above.
the image quality obtained at 7 Teslas with our dedicated coil allowed segmentation of the cartilage compartments with good reproducibility. This study demonstrated that MRI is a useful technology to provide a non-invasive and reliable assessment of rat knee cartilage volume.
评估定量磁共振成像（7T）在评估大鼠股骨 - 胫骨软骨体积方面的可靠性和可重复性。
使用7T实验成像仪对5只健康大鼠的膝关节进行活体扫描。采用专用自制的2元素阵列线圈进行矢状面高分辨率三维脂肪抑制梯度回波序列扫描。利用3D MRI数据集，通过触觉屏幕对3个软骨区域（股骨沟、内侧和外侧胫骨平台）进行手动分割。为评估观察者间和观察者内的可重复性，由两名经过培训的观察者在不知情的情况下进行分割操作。一名观察者重复操作两次，两次读数之间间隔10个月。
手动分割覆盖软骨关节的所有切片的平均时长为4小时。一方面，观察者间股骨、内侧和外侧胫骨区域变异系数的均方根分别为9.1%、6.2%、9.6%。另一方面，上述软骨区域的观察者内可重复性分别为2.1%、3.2%、2.5%。
使用我们的专用线圈在7T场强下获得的图像质量能够实现对软骨区域的分割，且具有良好的可重复性。本研究表明，MRI是一种有用的技术，可用于对大鼠膝关节软骨体积进行无创且可靠的评估。
