MR体素内不相干运动弥散加权成像及T2 mapping评估腰椎间盘退行性变

MR intravoxel incoherent motion diffusion weighted imaging and T2 mapping for evaluating lumbar intervertebral disc degeneration

目的观察MR体素内不相干运动弥散加权成像(IVIM-DWI)及T2 mapping技术评估腰椎间盘退行性变(IVDD)的价值。方法前瞻性纳入19例下腰部疼痛患者和31名健康志愿者,采集L1~S1椎体矢状位T2WI、T2 mapping及IVIM-DWI;根据Pfirrmann标准进行IVDD分级,观察不同分级及不同层面椎间盘T2值及其对应上、下位椎体IVIM参数的差异,并进行相关性分析,评价其诊断价值。结果不同Pfirrmann分级椎间盘之间,前纤维环(AAF)、髓核(NP)和后纤维环(PAF)T2值差异及对应下位椎体表观弥散系数(ADC)差异均有统计学意义(P均<0.05),不同层面椎间盘NP、PAF的T2值差异均有统计学意义(P均<0.05)。椎间盘PAF的T2值与其上、下位椎体ADC呈正相关(r=0.128、P=0.043,r=0.148、P=0.019);椎间盘Pfirrmann分级与AAF、NP及PAF的T2值均呈负相关(r=-0.187、P=0.003,r=-0.579、P<0.001,r=-0.401、P<0.001),与其上、下位椎体慢ADC(ADC_(slow))均呈正相关(r=0.196、P=0.002,r=0.126、P=0.046);椎间盘层面位置(L_(1-2)→L_(5)-S_(1))与NP及PAF的T2值均呈负相关(r=-0.183、P=0.004,r=-0.356、P<0.001),而与其上、下位椎体ADC_(slow)呈正相关(r=0.196、P=0.003,r=0.126、P=0.026)。结论IVIM-DWI及T2 mapping技术用于评估IVDD具有一定潜在价值,以椎间盘T2值及其对应下位椎体ADC的价值较高。

Objective To observe the value of MR intravoxel incoherent motion diffusion weighted imaging(IVIM-DWI)and T2 mapping for evaluating lumbar intervertebral disc degeneration(IVDD).Methods Nineteen patients with low back pain and 31 healthy volunteers were prospectively enrolled.Sagittal T2WI,T2 mapping and IVIM-DWI of L1—S1 vertebral bodies were collected,and IVDD was graded according to Pfirrmann standard.The differences of T2 values of intervertebral disc and IVIM parameters of corresponding upper and lower vertebral bodies of different Pfirrmann grades and different layers were observed,and the correlation analysis was performed to explore the diagnostic values.Results The differences of T2 values of anterior annulus fibrosus(AAF),nucleus pulposus(NP)and posterior annulus fibrosus(PAF)of different Pfirrmann grades and the apparent diffusion coefficient(ADC)of the corresponding lower vertebral body were all significant difference(all P<0.05),as well as T2 values of NP and PAF of different layers of intervertebral discs(both P<0.05).T2 value of PAF of intervertebral disc was positively correlated with ADC of upper and lower vertebral bodies(r=0.128,P=0.043;r=0.148,P=0.019),while Pfirrmann grade of intervertebral disc was negatively correlated with T2 values of AAF,NP and PAF(r=-0.187,P=0.003;r=-0.579,P<0.001;r=-0.401,P<0.001)but positively correlated with slow ADC(ADC_(slow))of upper and lower vertebral bodies(r=0.196,P=0.002;r=0.126,P=0.046).The position of intervertebral disc(L_(1-2)→L_(5)-S_(1))was negatively correlated with T2 values of NP and PAF(r=-0.183,P=0.004;r=-0.356,P<0.001)but positively correlated with ADC_(slow) of upper and lower vertebral bodies(r=0.196,P=0.003;r=0.126,P=0.026).Conclusion IVIM-DWI and T2 mapping had certain potential value for evaluating IVDD,and T2 value of intervertebral disc and ADC of corresponding lower vertebral body were more valuable.