Prognostic relevance of the postoperative evolution of intramedullary spinal cord changes in signal intensity on magnetic resonance imaging after anterior decompression for cervical spondylotic myelopathy
Prognostic relevance of the postoperative evolution of intramedullary spinal cord changes in signal intensity on magnetic resonance imaging after anterior decompression for cervical spondylotic myelopathy
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DOI：
10.3171/spi-07/12/615
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发表时间：
2007-12-01
影响因子：
2.8
通讯作者：
Ferrante, Luigi
中科院分区：
文献类型：
--
作者：
Mastronardi, Luciano;Elsawaf, Ahmed;Ferrante, Luigi
物体。脊髓型颈椎病(CSM)患者髓内信号强度改变的区域(T1加权磁共振[MR]图像为低信号，T2加权MR图像为高信号)已由多位研究者描述。这些改变在术后演变中的作用仍不是很清楚。共有47名患者在手术前和结束时接受了磁共振成像(术中磁共振成像[iMRI])，采用前路颈椎减压融合术。使用与手术室(BrainSuite)集成的1.5T扫描仪进行成像。术后3个月和6个月对患者进行临床随访，并使用日本骨科学会(JOA)和Nurick评分进行评估，并进行磁共振成像。47例中37例(78.7%)术前MRI显示髓内信号改变(与正常相比)。23例在T1和T2加权像上信号改变，14例仅在T2加权像上改变。术后T2加权像高信号消退12例(52.2%)。其中4例(17.4%)在手术结束时iMRI高信号消退。术后iMRI未发现残余压缩，术后最大压缩水平脊髓横径扩张与术后JOA评分和Nurick分级无明显相关性。在手术结果和患者临床病史的长短之间观察到有统计学意义的相关性。根据术前髓内信号改变的存在，也观察到显著的相关性。无脊髓信号改变的患者效果最好，仅在T2加权像上有信号改变的患者结果可接受，而在T1和T2加权图像上均有脊髓信号改变的患者的结果最差。最后，术后脊髓信号改变消退的患者与预后较好的患者之间存在统计学意义上的相关性。脊髓型颈椎病患者脊髓内信号强度的改变可以是可逆的(T2加权成像为高信号)，也可以是不可逆的(T1加权成像为低信号)。T2加权像上高信号区的消退与较好的预后相关，而T1加权低信号是不可逆损害的表现，因此预后最差。这一患者系列的初步经验似乎排除了信号强度恢复时间与CSM预后之间的关系。
Object. Areas of intramedullary signal intensity changes (hypointensity on T1-weighted magnetic resonance [MR] images and hyperintensity on T2-weighted MR images) in patients with cervical spondylotic myelopathy (CSM) have been described by several investigators. The role of postoperative evolution of these alterations is still not well known.Methods. A total of 47 patients underwent MR imaging before and at the end of the surgical procedure (intraoperative MR imaging [iMRI]) for cervical spine decompression and fusion using an anterior approach. Imaging was performed with a 1.5-tesla scanner integrated with the operative room (BrainSuite). Patients were followed clinically and evaluated using the Japanese Orthopaedic Association (JOA) and Nurick scales and also underwent MR imaging 3 and 6 months after surgery.Results. Preoperative MR imaging showed an alteration (from the normal) of the intramedullary signal in 37 (78.7%) of 47 cases. In 23 cases, signal changes were altered on both T1- and T2-weighted images, and in 14 cases only on T2-weighted images. In 12 (52.2%) of the 23 cases, regression of hyperintensity on T2-weighted imaging was observed postoperatively. In 4 (17.4%) of these 23 cases, regression of hyperintensity was observed during the iMRI at the end of surgery. Residual compression on postoperative iMRI was not detected in any patients.A nonsignificant correlation was observed between postoperative expansion of the transverse diameter of the spinal cord at the level of maximal compression and the postoperative JOA score and Nurick grade. A statistically significant correlation was observed between the surgical result and the length of a patient's clinical history. A significant correlation was also observed according to the preoperative presence of intramedullary signal alteration. The best results were found in patients without spinal cord changes of signal, acceptable results were observed in the presence of changes on T2-weighted imaging only, and the worst results were observed in patients with spinal cord signal changes on both T1- and T2-weighted imaging. Finally, a statistically significant correlation was observed between patients with postoperative spinal cord signal change regression and better outcomes.Conclusions. Intramedullary spinal cord changes in signal intensity in patients with CSM can be reversible (hyperintensity on T2-weighted imaging) or nonreversible (hypointensity on T1-weighted imaging). The regression of areas of hyperintensity on T2-weighted imaging is associated with a better prognosis, whereas the T1-weighted hypointensity is an expression of irreversible damage and, therefore, the worst prognosis. The preliminary experience with this patient series appears to exclude a relationship between the time of signal intensity recovery and outcome of CSM.