Prognostic value of changes in spinal cord signal intensity on magnetic resonance imaging in patients with cervical compressive myelopathy
Prognostic value of changes in spinal cord signal intensity on magnetic resonance imaging in patients with cervical compressive myelopathy
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DOI：
10.1016/j.spinee.2013.09.038
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发表时间：
2014-08-01
期刊：
影响因子：
4.5
通讯作者：
Baba, Hisatoshi
中科院分区：
文献类型：
--
作者：
Uchida, Kenzo;Nakajima, Hideaki;Baba, Hisatoshi
背景：术前脊髓颈椎磁共振成像 (MRI) 的信号强度已被证明是颈椎压迫性脊髓病手术结果的潜在预测因素。然而，此类信号的预后价值仍然存在争议。争议的原因之一是缺乏适当的定量方法来评估 MRI 信号强度。目的：量化信号强度并将 MRI T1 和 T2 加权图像 (WI) 上的髓内信号变化与临床结果和预后相关联。研究设计：回顾性病例研究。患者样本：患者（n=148；脊髓型颈椎病，n=102 和骨化后纵骨） 2006 年至 2010 年间，因脊髓型颈椎病接受手术且术前矢状位 T2-WI MRI 出现高信号强度变化的韧带，n=46）。 结果测量：采用日本骨科协会 (JOA) 脊髓型颈椎病评分系统进行神经系统评估。使用术前和术后 JOA 评分计算神经功能改善率。 方法：通过使用信号强度比（SIR；病变相对于 C7-T1 椎间盘水平的信号强度）对 T1 和 T2-WI 上的 MRI 信号进行定量分析。分析 T1 和 T2-WI 上的 SIR 与术前 JOA 评分、JOA 改善率、病程和 MRI 形态分类（囊性或弥漫型）之间的相关性。还对 JOA 改善率进行了多变量回归分析。在一项子研究中，25 名患者从术后 6 个月开始接受了随访 MRI，以分析随访 MRI 中 SIR 的变化与临床结果之间的关系。 结果：T1-WI 上的 SIR 与术后神经功能改善相关，但 T2-WI 上的 SIR 不相关。病程与 T1-WI 上的 SIR 和 JOA 改善率呈负相关，但与 T2-WI 上的 SIR 无关。 “囊性型”的 T2-WI 的 SIR 显着大于“弥漫型”，但两种类型的 T1-WI 的 SIR 和 JOA 改善率没有差异。逐步多元回归分析表明，T1-WI 上的 SIR 和长病程是术后神经系统结果的重要预测因素。随访T1-WI的SIR和术后T1-WI的SIR变化与术后改善率呈正相关。随访 T2-WI 的 SIR 和 T2-WI 的变化与术后神经系统改善呈负相关。结论：我们的结果表明，术前 T1-WI 的低强度信号（而非 T2-WI）与术后神经系统预后不良相关。此外，信号减弱
BACKGROUND CONTEXT: Signal intensity on preoperative cervical magnetic resonance imaging (MRI) of the spinal cord has been shown to be a potential predictor of outcome of surgery for cervical compressive myelopathy. However, the prognostic value of such signal remains controversial. One reason for the controversy is the lack of proper quantitative methods to assess MRI signal intensity.PURPOSE: To quantify signal intensity and to correlate intramedullary signal changes on MRI T1-and T2-weighted images (WIs) with clinical outcome and prognosis.STUDY DESIGN: Retrospective case study.PATIENT SAMPLE: Patients (n=148; cervical spondylotic myelopathy, n=102 and ossified posterior longitudinal ligament, n=46) who underwent surgery for cervical compressive myelopathy and had high signal intensity change on sagittal T2-WI MRI before surgery between 2006 and 2010.OUTCOME MEASURE: Neurologic assessment was conducted with the Japanese Orthopedic Association (JOA) scoring system for cervical myelopathy. The rate of neurologic improvement was calculated with the use of preoperative and postoperative JOA scores.METHODS: Quantitative analysis of MRI signal on both T1-and T2-WIs via use of the signal intensity ratio (SIR; signal intensity of lesion relative to that at C7-T1 disc level) was performed. Correlations between SIR on T1-and T2-WIs and preoperative JOA score, JOA improvement rate, disease duration, and MRI morphologic classification (cystic or diffuse type) were analyzed. Multivariate regression analysis for JOA improvement rate was also analyzed. In a substudy, 25 patients underwent follow-up MRI starting from 6 months after surgery to analyze the relationship between changes in SIR on follow-up MRI and clinical outcome.RESULTS: SIR on T1-WIs, but not SIR on T2-WIs, correlated with postoperative neurologic improvement. The disease duration correlated negatively with SIR on T1-WIs and JOA improvement rate but not with SIR on T2-WIs. SIR on T2-WIs of "cystic type'' was significantly greater than of "diffuse type,'' but SIR on T1-WI and JOA improvement rate were not different in the two types. Stepwise multivariate regression analysis indicated that SIR on T1-WIs and long disease duration were significant predictors of postoperative neurologic outcome. SIR on follow-up T1-WI and changes in SIR on T1-WI after surgery correlated positively with postoperative improvement rate. SIR on follow-up T2-WI and changes on T2-WI correlated negatively with postoperative neurologic improvement.CONCLUSIONS: Our results suggest that low intensity signal on preoperative T1-WIs but not T2-WIs correlated with poor postoperative neurologic outcome. Furthermore, decreased signal