采用3.0T MRI T2和T2* mapping评价下腰痛患者腰椎间盘退变

目的探讨下腰痛患者腰椎间盘的T2和T2*值与退变Pfirrmann分级的相关性,明确T2和T2*值是否可以作为影像学生物标记定量评价IVD退变。方法 2015年3月-2015年6月间,对66例下腰痛患者采用3.0T MRI行腰椎常规结构成像和定量成像(T2和T2*mapping)。Pfirrmann分级由两位放射诊断医生依据矢状位T2WI通过协商进行。在正中矢状位的T2 map和T2*map上由一位放射诊断医生手工绘制感兴趣区尽可能包括髓核和内层纤维环测量IVD的T2和T2*值。采用Pearson相关比较IVD的T2和T2*值与Pfirrmann分级相关性,并对相邻的Pfirrmann分级的T2和T2*值比较。结果 IVD的T2和T2*值与Pfirrmann分级呈负相关,相关系数分别为-0.612和-0.354,P值均小于0.001。PfirrmannⅠ级到Ⅲ级T2和T2*值显著降低,Ⅲ级到Ⅴ级下降变缓。除Ⅳ级与Ⅴ级IVD的T2和T2*值差别没有统计学意义外,其他相邻的Pfirrmann分级IVD的T2和T2*值差别均有统计学意义。结论 IVD的T2和T2*值具有作为影像学生物标记定量评价IVD的退变潜在可能性,有助于IVD退变的早期诊断和客观评价退变程度。晚期IVD退变T2和T2*值下降变缓,以形态学改变为主。

T2 and T2* Mapping to Evaluate Lumber Intervertebral Disc Degeneration in Patients with Low Back Pain Using 3.0 Tesla MRI

Objective To correlate T2 and T2* value of intervertebral disc (IVD) with Pfirrmann grades of IVD degeneration in patients with low back pain, in order to identify whether T2 and T2* value can be imaging biomarkers for quantitative assessment of IVD degeneration.Methods Sixty-six patients with low back pain underwent conventional structure imaging and quantitative imaging (T2 and T2* mapping) of lumber IVD using 3 Tesla MR system. Pfirrmann grades were performed by two diagnostic radiologists in concensus on the basis of the sagittal T2-weighted images. T2 and T2* values of IVD were measured by one diagnostic radiologist through manual drawing region-of-interest (ROI) on midsagittal T2 and T2* maps to cover the nucleus pulposus and inner annulus fibrosus. The correlation between Pfirrmann grades and the two quantitative parameters of IVD was assessed by Pearson correlation test. The difference in T2 and T2* values of contiguous Pfirrmann grades were compared using t test.Results T2 and T2* values of IVD were of negative correlation to Pfirrmann grades with correlation coefficients of -0.612 and -0.354 (P<0.001), respectively. Except grades Ⅳ andⅤ, T2 and T2* values of contiguous Pfirrmann grades showed statistical significant differences.Conclusion T2 and T2* values of IVD could be potential imaging biomarkers for quantitative assessment of IVD degeneration, which might be helpful of early diagnosis and objective evaluation of degeneration. For the end stage degeneration, the decrease of T2 and T2* values is slow down, and morphological changes become obvious.