Department of Orthopaedics and Rehabilitation Medicine, Faculty of Medical Sciences, University of Fukui, Matsuoka Shimoaizuki 23, Eiheiji, Fukui, 910-1193, Japan.
Eur J Nucl Med Mol Imaging. 2012 Oct;39(10):1528-37. doi: 10.1007/s00259-012-2192-y. Epub 2012 Aug 2.
(18)F-FDG PET is used to investigate the metabolic activity of neural tissue. MRI is used to visualize morphological changes, but the relationship between intramedullary signal changes and clinical outcome remains controversial. The present study was designed to evaluate the use of 3-D MRI/(18)F-FDG PET fusion imaging for defining intramedullary signal changes on MRI scans and local glucose metabolic rate measured on (18)F-FDG PET scans in relation to clinical outcome and prognosis.
We studied 24 patients undergoing decompressive surgery for cervical compressive myelopathy. All patients underwent 3-D MRI and (18)F-FDG PET before surgery. Quantitative analysis of intramedullary signal changes on MRI scans included calculation of the signal intensity ratio (SIR) as the ratio between the increased lesional signal intensity and the signal intensity at the level of the C7/T1 disc. Using an Advantage workstation, the same slices of cervical 3-D MRI and (18)F-FDG PET images were fused. On the fused images, the maximal count of the lesion was adopted as the standardized uptake value (SUV(max)). In a similar manner to SIR, the SUV ratio (SUVR) was also calculated. Neurological assessment was conducted using the Japanese Orthopedic Association (JOA) scoring system for cervical myelopathy.
The SIR on T1-weighted (T1-W) images, but not SIR on T2-W images, was significantly correlated with preoperative JOA score and postoperative neurological improvement. Lesion SUV(max) was significantly correlated with SIR on T1-W images, but not with SIR on T2-W images, and also with postoperative neurological outcome. The SUVR correlated better than SIR on T1-W images and lesion SUV(max) with neurological improvement. Longer symptom duration was correlated negatively with SIR on T1-W images, positively with SIR on T2-W images, and negatively with SUV(max).
Our results suggest that low-intensity signal on T1-W images, but not on T2-W images, is correlated with a poor postoperative neurological outcome. SUV(max) of lesions showing increased signal intensity and SUVR measured on fusion MRI/PET scans are more sensitive parameters for predicting clinical outcome than signal intensity on the MRI scan.
（18）F-FDG PET 用于研究神经组织的代谢活性。MRI 用于观察形态学变化，但髓内信号变化与临床结果之间的关系仍存在争议。本研究旨在评估使用 3-D MRI/(18)F-FDG PET 融合成像来定义 MRI 扫描上的髓内信号变化以及（18）F-FDG PET 扫描上测量的局部葡萄糖代谢率与临床结果和预后的关系。
我们研究了 24 例因颈椎压迫性脊髓病而行减压手术的患者。所有患者均在术前接受了 3-D MRI 和（18）F-FDG PET 检查。MRI 扫描上髓内信号变化的定量分析包括计算信号强度比（SIR），即病变信号强度与 C7/T1 椎间盘水平信号强度的比值。使用 Advantage 工作站，将颈椎 3-D MRI 和（18）F-FDG PET 图像的相同切片融合。在融合图像上，采用病变的最大计数作为标准化摄取值（SUV(max)）。以类似的方式计算 SUV 比（SUVR）。采用日本矫形协会（JOA）颈椎脊髓病评分系统对神经功能进行评估。
T1 加权（T1-W）图像上的 SIR，但 T2 加权（T2-W）图像上的 SIR 与术前 JOA 评分和术后神经改善无显著相关性。病变 SUV(max)与 T1-W 图像上的 SIR 显著相关，但与 T2-W 图像上的 SIR 不相关，与术后神经功能结局也显著相关。SUVR 与 T1-W 图像上的 SIR 和病变 SUV(max)与神经改善的相关性均优于 SIR。症状持续时间较长与 T1-W 图像上的 SIR 呈负相关，与 T2-W 图像上的 SIR 呈正相关，与 SUV(max)呈负相关。
我们的结果表明，T1-W 图像上的低信号强度，而不是 T2-W 图像上的信号强度，与术后神经功能不良相关。显示信号强度增加的病变的 SUV(max)和融合 MRI/PET 扫描上测量的 SUVR 是预测临床结果的比 MRI 扫描上的信号强度更敏感的参数。
