中轴型脊柱关节病活动性骶髂关节炎~1H-MRS初探

目的探讨中轴型脊柱关节病活动性骶髂关节炎1H-MRS频谱特征及意义。材料与方法对10例经临床和常规MRI确诊为中轴型脊柱关节病活动性骶髂关节炎患者(病例组,含活动组和非活动组)及同期11例健康志愿者(对照组)行双侧骶髂关节斜冠状面FSE序列T1WI、STIR序列T2WI,1H-MRS检查。常规MRI图像由2名MR诊断医师在工作站盲法分别进行阅片。应用LCModel软件对MRS资料进行后处理,观察水峰、脂质峰位置,记录水脂比并作统计学分析。结果所有研究对象均获得满意的骶髂关节频谱图,可观察到多个代谢物波峰:位于0.9 ppm的甲基峰,位于1.3 ppm、1.6 ppm、2.0 ppm的亚甲基峰,位于5.3 ppm的乙烯基峰及位于4.7 ppm的水峰。活动组、非活动组和对照组水脂比分别为(1.71±1.14)、(0.43±0.08)、(0.42±0.23);活动组水脂比高于对照组及非活动组,差异有统计学意义(Z=-4.46、-2.92,均P0.05),对照组与非活动组之间水脂比相接近,差异无统计学意义(Z=-0.87,P0.05)。结论 1H-MRS可以在常规MRI基础上量化骶髂关节炎的水肿程度,有望成为评价骶髂关节炎症活动性的一种无创性的新手段。

Evaluation of1H-MRS in detecting active sacroiliitis in patients with axial spondyloarthritis

AbstractObjective: To evaluate the value and characteristics of proton magnetic resonance spectroscopy (1H-MRS) in detecting active Sacroiliitis in patients with axial Spondyloarthritis (SpA).Materials and Methods:1H-MRS and conventional MRI examinations were done oblique coronary on bilateral SIJs of 21 participants, involving 10 patients (the case group, including active a.nd inactive case groups) underwent clinical and conventional MRI evaluation for axial SpA active sacroiliitis and 11 healthy volunteers (the control group). The conventional MRI images were transmitted to two experienced radiologists respectively to read, evaluate at the workstation under the blind method. The spectrum image analysis was carried out with the LCModel software, and water to lipid ratio (WLR) was calculated for statistical analysis.Results:1H-MRS spectra of the sacroiliac joints shows several metabolite peaks: the peak around 0.9 ppm is from the methyl protons, the 1.3 ppm, 1.6 ppm and 2.0 ppm are assigned to the methylene protons of the lipid chain, the 5.2 ppm is from the oleifnic protons, and the water peak is at 4.7 ppm. The area under the water peak and the major lipid peak were used to calculate water to lipid ratio (WLR). The mean value of WLR were compared from all the three groups (active case group, 1.71±1.14, inactive case group, 0.43±0.08, and healthy control group, 0.42±0.23). The WLR of active case group were higher than both the inactive case group and the healthy control group, and the differences were statistically signiifcant(Z=-4.46,-2.92, allP<0.05). However, the WLR between the inactive case group and the healthy control group was similar with no signiifcant difference(Z =-0.87,P>0.05).Conclusions:1H-MRS can quantify the bone marrow edema of sacroiliitis based on the conventional MRI, which maybe a new noninvasive method of assessing the activity of sacroiliitis.