腰椎间孔MRI和CT三维测量的对比分析

Three-dimensional analysis of lumbar intervertebral foramina using MRI and CT: a comparison study

目的对比分析腰椎间孔MRI和CT三维数据,提高腰椎间孔三维测量的准确性。方法收集2013年8月—2016年8月间的56例腰椎退变病人[男24例、女32例,年龄39~72岁,平均(56.5±7.6)岁]和41名体检腰椎正常者[男18名、女23名,年龄25~36岁,平均(31.4±5.2)岁]的MRI和CT影像资料。采用Mimics19.0软件构建腰椎间孔MRI和CT三维模型,分别测量腰椎间孔容积、矢状面最小面积及冠状面长径,测量数据间的比较采用配对样本t检验。采用组内相关系数(ICC)评价不同测量者之间的一致性。结果不同测量者之间存在较高的一致性(均ICC>0.9)。腰椎正常者MRI上测得的L1~S1各节段椎间孔容积及L1/L2、L2/L3、L3/L4、L4/L5节段的矢状面最小面积均小于CT测量结果(均P<0.05);腰椎退变病人MRI上测得的L1~S1各节段的椎间孔容积以及L1/L2和L2/L3节段的椎间孔矢状面最小面积均小于CT测量结果(均P<0.05)。腰椎退变病人及腰椎正常者其余测量值差异均无统计学意义(均P>0.05)。结论腰椎间孔MRI和CT三维测量数据之间存在差异,主要是由于CT成像尚不能精确识别未发生显著退行性改变的椎间孔后壁软组织。

Objective To improve the measurement accuracy of lumbar intervertebral foramen by analyzing the three-dimensional data obtained from MRI and CT. Methods The MRI and CT data of 56 patients with lumbar degenerative diseases (24 men, 32 women;age 56.5±7.6 years,range 39~72 years) and 41 healthy adults (18 men, 23 women;age 31.4±5.2 years,range 25~36 years) were collected from August 2013 to August 2016. Lumbar foramen three-dimensional models of MRI and CT were created using mimics 19.0 software. The volume, sagittal minimum area, and coronal length of lumbar foramina were measured and compared between MRI and CT using t-test. Intraclass correlation coefficient (ICC) was used to evaluate the agreements of the measurements from MRI and CT models. Results There was high agreement between different measurers (ICC>0.9). In the healthy group, the foramina volume on L1~S1 levels and sagittal minimum area on L1/L2,L2/L3,L3/L4 and L4/L5 levels in MRI models was significantly smaller than that in CT models(P<0.05). In the degenerative lumber group,the foramina volume on L1-S1 levels and sagittal minimum area on L1/L2 and L2/L3 in MRI models was significantly smaller than that in CT models(P<0.05). The other data between two groups existed no statistical difference(P>0.05). Conclusions The measurements of lumbar foramen obtained from the MRI and CT differs significantly. The main cause is that posterior soft tissue of lumbar foramen cannot be accurately identified on CT in people without degeneration.