腰椎间盘退变的MR定量分析:MRS和T1ρ成像技术

Quantitative study of lumbar disc degeneration:MRS and T1ρ

目的探讨MRS和T1ρ成像技术定量评估腰椎间盘的退变程度的应用价值。方法收集腰痛患者64例,按年龄分为<30岁组(10例)、30～39岁组(12例)、40～49岁组(11例)、50～59岁组(15例)、>59岁组(16例)。对每例患者选取2个腰椎间盘进行MRS扫描,获得髓核氮-乙酰氨基峰下面积(N-acetyl)、水峰下面积(Water),及N-acetyl/Water值;并行T1ρ成像,分别测量髓核及纤维环T1ρ值。比较不同Pfirrmann分级及年龄组间MRS及T1ρ定量分析结果的差异,并分析Pfirrmann分级和年龄与T1ρ和MRS定量分析结果的相关性。结果 64例患者共128个椎间盘中,PfirrmannⅡ级61个,Ⅲ级40个,Ⅳ级23个,Ⅴ级4个。不同Pfirrmann分级椎间盘间及不同年龄组间,髓核T1ρ、N-acetyl、Water及N-acetyl/Water值差异均有统计学意义(P均<0.01),纤维环T1ρ值差异无统计学意义(P>0.05)。N-acetyl、Nacetyl/Water、髓核T1ρ值,随Pfirrmann分级增加、患者年龄增大,均呈下降趋势。结论 MRS和T1ρ成像技术均可用于腰椎间盘退变的定量评估,且与Pfirrmann分级具有良好的相关性。

Objective To investigate the application value of MRS and T1ρimaging in quantitative evaluation of the degeneration of lumbar discs.Methods Sixty-four patients with low back pain were enrolled.The patients were divided into five groups:<30 years old(n=10),30—39 years old(n=12),40—49 years old(n=11),50—59 years old(n=15),>59 years old(n=16).Two lumbar discs were selected for MRS scan in each patient to obtain the N-acetylamino(N-acetyl)and water peak of the nucleus pulposus.And the ratio of N-acetyl and water peak of the nucleus pulposus(Nacetyl/Water)was calculated.T1ρvalues of the nucleus pulposus and the annulus fibrosis was measured.And the differences of quantitative evaluation results among different Pfirrmann grades and age groups were analyzed.The correlation between T1ρ,MRS quantitative evaluation results and Pfirrmann grading,age were also observed,respectively.Results Totally 128 intervertebral discs in 64 patients were analyzed.Among them,there were 61 discs of PfirrmannⅡ,40 discs of Pfirrmann Ⅲ,23 discs of Pfirrmann Ⅳ,4 discs of Pfirrmann Ⅴ.There were significant differences of T1ρvalue in nucleus pulposus,N-acetyl peak,water peak and N-acetyl/water among different Pfirrmann grades intervertebral discs and different age groups(all P<0.01).While there was no statistical difference of T1ρvalue in annulus fibrosus(P>0.05).N-acetyl peak,N-acetyl/water and T1ρvalue in nucleus pulposus increased with the increasing of Pfirrmann grades and the age of patients.Conclusion Both of MRS and T1ρimaging can be used for quantitative assessment of lumbar disc degeneration which have good correlation with Pfirrmann grading.