轴向负荷 MR 检查在腰椎退行性疾病中的诊断价值

The diagnosis value of axially loaded position MRI for lumbar degenerative disease

目的：探讨轴向负荷（ALP）MRI 在腰椎退行性疾病（LDD）诊断中的有效性和优势。方法选择重庆医科大学附属第二医院骨科2013年11月—2014年10月84例患有 LDD 病例纳入研究组进行回顾性分析。患者均先行常规仰卧腰大肌放松体位（RPRP）MR 检查；再在 ALP 加压后行MR 检查,测量 RPRP 体位和 ALP 体位 MR 检查下硬膜囊横截面积（DSCA）。根据 ALP 体位下 MR 检查过程中的症状复制情况分为阳性组及阴性组,对2组各自的 DSCA 的变化情况进行统计学分析。结果与 RPRP 体位 MR 检查相比,ALP 体位 MR 检查下 DSCA 明显缩小（〉15 mm2）者49例（58.3%,49/84）,76个椎间盘（30.2%,76/252）；两种不同体位 MR 检查 L3/4、L4/5、L5/ S1的 DCSA 差异均有统计学意义（P 值均〈0.05）；且 ALP 体位 MR 检查中复制临床症状阴性组与阳性组之间,L4/5与 L5/ S1水平 DSCA 缩小的程度差异均有统计学意义（P 值均〈0.05）,而 L3/4水平差异无统计学意义（P 〉0.05）。结论对于 LDD 患者,与 RPRP 体位 MR 检查相比,ALP 体位 MR 检查复制出临床症状的患者与其余患者 DSCA 缩小情况在 L4/5、L5/ S1椎间盘有差异,ALP 体位 MR 检查能提高症状与轴向负荷加压 MR 检查的相关性,提高了诊断阳性率,可发现隐匿性滑脱及椎间孔狭窄。对于临床症状、体征与影像学检查不符的患者也有一定的诊断价值。

Objective To investigate the efficacy and advantage of axially loaded position MRI for the diagnosis of lumbar degenerative disease （ LDD）. Methods To review 84 patients of LDD in the Second Affiliated Hospital of Chongqing Medical University from November 2013 to October 2014, and all the patients were examined by routine psoas relaxed position （ RPRP） MRI and axially loaded position （ALP） MRI. Meanwhile, the size of the dural sac cross-sectional area （DSCA） was recorded. According to whether the symptom was replicable in extension position with axial loaded, all patients were divided into two groups （the negative and the positive groups）. The difference of DSCA changes between these two groups was statistically analysed. Results Compared with RPRP, there was a significant decrease （ 〉 15 mm2 ） of the DSCA during ALP in 49 patients （58. 3% , 49 / 84） and 76 disc levels （30. 2% , 76 / 252）. Meanwhile, the differences of DSCA between these two postures in L3 / 4 , L4 / 5 or L5 / S1 were statistically significant （all P values 〈 0. 05）. Of note, in L4 / 5 and L5 / S1 , the variations of DSCA in the negative and the positive groups during ALP were statistically different （all P values 〈 0. 05）. However, in L3 / 4 , there was no statistical difference （ P 〉 0. 05）. Conclusions For LDD, compared with RPRP, the variations of DSCA in the negative and the positive groups during ALP are statistically different in L4 / 5 and L5 / S1 , and ALP can further improve the correlation between symptoms and MRI. And thus, it can also improve the positive rate, especially occult slippage and intervertebral foramen stenosis. Meanwhile, for the patients with inconsistent clinical symptoms, physical signs and imaging examination, the diagnostic value is superior.