64层CT脊髓造影多平面重组对颈神经根损伤的诊断价值

The value of multiplanar reconstruction using 64-slice CT myelography in cervical nerve root injury

目的前瞻性研究64层 CT 的脊髓造影(CTM)多平面重组(MPR)在颈神经根损伤中的诊断价值及其替代直接扫描横断面图像及常规 X 线脊髓造影的可能性。方法对26例临床诊断为颈神经损伤患者进行 X 线脊髓造影和64层 CT 各向同性扫描,然后进行 MPR 成像,并进行 MPR 多方向调整,使病变显示于冠状、矢状和横断面上。其中26例(54个神经根)进行了手术探查并有术后诊断结果,就其冠状、矢状断面 MPR 图像、直接扫描 CT 横断面图像、脊髓造影平片对病变的诊断符合率进行对比,并比较横断面 MPR 与直接扫描横断而 CT 的图像数量。结果以患侧蛛网膜下腔内颈神经根前后支走行区和神经孔处充盈缺损消失,连续性无神经根显示为直接征象,CTM 发现神经根损伤31个。间接征象表现为:(1)创伤性脊膜膨出:椎管内患侧硬膜囊膨大、变形,呈柱形高密度影,并可沿椎间孔向外延伸,形成神经根鞘膜囊肿,与蛛网膜下腔间有低密度的细线状分隔,在撕裂水平可见29个膨出。(2)蛛网膜囊肿:硬膜囊一侧膨大变形,呈囊样扩张,病变未经椎间孔向外延伸,与蛛网膜下腔间有细线状分隔26个。(3)蛛网膜下腔不对称:一侧腔变窄,脊髓有不同程度的移位,多层面显示各神经根走行区未见连续性充盈缺损17个。64层 CT 多向调整的冠状面 MPR 对病变的诊断符合率为92.6%(50/54个),高于直接扫描 CT 横断图像(77.8%,42/54个)及平片(68.5%,37/54个),3种影像方法与术后诊断结果进行 Kappa 一致性检验比较,X 线平片、CTM 横断面和曲面冠状 MPR 的 Kappa 值分别为0.686、0.772、0.920,P 值均<0.05。可见曲面冠状 MPR 与手术诊断结果高度一致。而图像数量明显少于横断面 CT(MPR 50幅图像,横断面 CT 400幅图像)。结论多向调整的冠状面 MPR 解决了多层 CT 图像数量庞大的问题,该方法省时、易行,可直观清晰显示颈神经根损伤范围,提高了诊断符合率。

Objective To study the diagnostic value of multi-direction adjusted multiplanar reconstruction （MPR） by 64-slice CT myelography （CTM） in diagnosing cervical nerve injury, and the possibility of the MPR to replace conventional myelography and CT direct-scanning axial images. Methods Twenty-six patients with cervical nerve root injury were examined by conventional myelography and 64-slice CT using isotropic parameters. Then multi-direction MPR were performed to display nerve roots on coronal and sagittal planes besides axial images. Twenty-six patients were performed surgical operations and diagnosis were obtained. The coincident diagnosing rate with surgical operations results were compared statistically among multi-direction MPR, direct-scanning axial CT images, conventional myelography. The numbers of images were also compared between axial MPR and direct scanning axial CT images. Results Direct sign of nerve root avulsion was the loss of normal nerve root defect seen in the lsovist filled thecal sac in 64-slice CT, which was found in 31 nerve roots. Indirect signs included： （1） Traumatic pseudomeningocele： 29 nerve roots showed the leak of lsovist into nerve root sheath, and extended into foramina; （2） Arachnoid cyst： 26 nerve roots clearly displays cystic distension in nerve root, which has lowdensity fine clew form septation from subarachnoid cavity and no nerve root in the cyst ; （ 3 ） Deformity of the subarachnoid space ： deformity of thecal sac, partially lack of Isovist into arachnoid space, which was found in 17 nerve roots. The coincident diagnosing rate of cervical nerve root injury by muhi-direction adjusted coronal MPR imaging was 92.6% （50/54）, which was higher than by axial CT （77. 8%, 42/54 ） and conventional myelography （68.5%, 37/54）, There was significant difference between the conventional myelography, direct-scanning axial CT, multi-direction MPR images （ Kappa = 0. 686, 0. 772, 0. 920, respectively, P 〈 0.05 ） , the coronal MPR imaging was significantly higher than those of the other two imaging modalities. The number of long-axial MPR images was much fewer than that of axial CT images （ MPR 50 images, axial CT 400 images）. Conclusion Multi-direction adiusted coronal MPR has solved the problem of too many images by multi-slice CT , and it displayed the extension roundly and directly , and it would be an effective method for cervical nerves root injury, and it greatly improves diagnostic accuracy, and it is the trend of CT diagnosing of cervical nerves root iniury.