Gandy S J, Dieppe P A, Keen M C, Maciewicz R A, Watt I, Waterton J C
Department of Medical Physics & Bioengineering, Bristol General Hospital, Guinea St, Bristol BS1 6SY, UK.
Osteoarthritis Cartilage. 2002 Dec;10(12):929-37. doi: 10.1053/joca.2002.0849.
Magnetic resonance imaging (MRI) has the potential to provide accurate quantification of structural changes in joint disease, with sensitivity to change, as it can provide direct visualization of the cartilage and bone. In this study, we investigated whether knee cartilage volume, as assessed by MRI, is sensitive to change over time in patients with osteoarthritis (OA).
Sixteen patient volunteers (10 male, six female) with established OA of the knee were entered into the study and demographic data recorded. At baseline, 12 months and 37+/-2 months, patients underwent simple measures of disease severity, as well as extended weight-bearing AP knee X-rays. In addition the patient's index knee was imaged using MR at 1.0 T using a 3-D spoiled gradient-echo sequence with fat-suppression, repetition time 50 ms, echo time 11 ms, flip-angle 40 degrees, sagittal slice thickness 1.56 mm and in-plane pixel resolution 0.55 mm. Manual image segmentation was performed on all knee cartilage compartments and the respective cartilage volumes determined.
Eleven of the original patients recruited completed the 3-year study. Radiographic features indicated that the majority had a spectrum of well-established OA at entry. The average decrease in medial tibiofemoral joint space width was 0.21+/-0.37 mm (mean+/-S.D.). Comparison of MR images at baseline and 37+/-2 months indicated little evidence of cartilage lesion shape or size change in any of the compartments. There was no significant MRI volume change in any of the knee cartilage compartments over the course of 1 year. The change in total knee cartilage volume, as measured by MRI, was a loss of only 1.6%, or 0.36+/-1.3 ml (mean+/-S.D.), over the 3 years.
The failure to identify loss of cartilage volume over 3 years in this cohort of patients with established knee OA using MRI challenges the face validity of this endpoint to assess structural changes in OA.
磁共振成像（MRI）有潜力对关节疾病的结构变化进行准确量化，并具有对变化的敏感性，因为它能直接显示软骨和骨骼。在本研究中，我们调查了通过MRI评估的膝关节软骨体积在骨关节炎（OA）患者中随时间的变化是否敏感。
16名确诊为膝关节OA的患者志愿者（10名男性，6名女性）进入本研究，并记录人口统计学数据。在基线、12个月和37±2个月时，患者接受疾病严重程度的简单测量，以及负重位膝关节前后位X线片检查。此外，使用1.0T磁共振成像对患者的患侧膝关节进行成像，采用三维扰相梯度回波序列并脂肪抑制，重复时间50ms，回波时间11ms，翻转角40度，矢状位层厚1.56mm，平面像素分辨率0.55mm。对所有膝关节软骨区域进行手动图像分割，并确定各自的软骨体积。
最初招募的16名患者中有11名完成了3年的研究。影像学特征表明，大多数患者在入组时患有一系列明确的OA。胫股内侧关节间隙宽度平均减少0.21±0.37mm（均值±标准差）。基线和37±2个月时的MRI图像比较表明，在任何区域均几乎没有软骨损伤形状或大小变化的证据。在1年的时间里，任何膝关节软骨区域的MRI体积均无显著变化。通过MRI测量，全膝关节软骨体积在3年中仅减少了1.6%，即0.36±1.3ml（均值±标准差）。
在这组确诊为膝关节OA的患者中，使用MRI未能在3年内识别出软骨体积的减少，这对该终点评估OA结构变化的表面效度提出了挑战。
