脊椎术后感染MRI诊断价值

THE VALUE OF MRI IN THE DIAGNOSIS OF POSTOPERATIVE INFECTION OF VERTEBRAL COLUMN

目的分析脊椎术后感染的MRI表现,以提高对其认识。方法回顾性分析32例经临床证实的脊椎术后感染病例,其中行MRI平扫检查24例,平扫和增强扫描检查7例,直接增强扫描检查1例,观察椎间盘炎、脊椎骨髓炎、硬膜外脓肿及软组织感染MRI平扫和增强扫描的表现。结果椎间盘炎(20例):椎间盘破坏、髓核裂隙消失、终板破坏及椎间隙变窄,MRI平扫呈等(长)T1、长T2信号17例,等T1、短T2信号1例,椎间盘信号正常1例;增强扫描5例,斑点状强化1例,不规则强化4例。骨髓炎(22例):20例为脊椎骨髓炎并椎间盘炎,2例为单纯脊椎骨髓炎,平扫病变呈长(短)T1、长T2信号4例(6个椎体),呈长T1、长T2信号17例(39个椎体);增强扫描6例(12个椎体)病变区均有强化。硬膜外脓肿(15例):呈等T1、长T2信号,增强扫描明显强化,5例有脓腔形成,呈长T1、长T2信号,增强扫描无强化;2例脊髓内有斑片状水肿信号。软组织感染(10例):6例有脓肿形成,周围伴广泛软组织水肿,4例为蜂窝组织炎;增强扫描脓肿壁、周围软组织水肿及蜂窝组织炎有强化。结论脊椎术后椎间盘炎、骨髓炎、硬膜外脓肿和软组织感染MRI表现较有特征性,MRI能早期发现病变,对改善病人预后具有重要的临床意义。

Objective To analyze MRI appearance of infection of the postoperative spine. Methods A retrospective review was carried out in 32 patients infected after surgery for vertebral column who were confirmed clinically. Of whom, 24 under went plain MRI scan, seven underwent plain scan plus enhancement scanning, and one underwent a direct enhancement scanning, the appearance of discitis, osteomyelitis of vertebral column, epidural abscess, and soft tissue infection on the above scans was ob- sei＇ved. Results Discitis （20 cases） ： disc destructed, nucleus puiposus disappeared, lamina terminalis destructed and interverte- bral space narrowed. Plain MRI scan showed： plain isointense or hypointense on Tl-weighted images and hyperintense on T2- weighted images in 17 cases, isointense on Tl-weighted images and hypointense on T2-weighted images in one case, one with nor- mal disc signal. Five underwent contrast-enhanced scan showed nodular enhancement in one case, and patchy enhancement in four. Osteomyelitis was noted in 22 cases, which included 20 with spinal osteomyelitis and discitis, two with merely spinal osteomyelitis. A plain scan showed hyper- or hypointense on Tl-weighted images and hyperintense on T2-weighted images in four cases （six verte- brae）, hyperintense Tl-weighted signal and hyperintense T2-weighted signal in 17 cases （39 vertebrae）. An enhancement scanning done in six cases （12 vertebrae） indicated that the all diseased region were enriched. Epidural abscess 15 cases, appeared as isoin tense Tl-weighted and hyperintense Tz-weighted signal, an enhancement scan showed obviously enriched; an abscess cavity was noted in five cases, the signals appeared as hyperintense T1- and T2-weighted, no reinforcement was observed after enhancement scanning. Edema of spinal cord found in two cases. Soft tissue infection in 10 cases： abscessation was noted in six cases with exten- sive edema surrounded, and four with phlegmon, an enhancement scan indicated enrichment in the wall of the abscess and around the soft tissue. Conclusion The manifestations of discitis, osteomylitis, epidural abscess, and soft tissue infection on MRI after surgery of the spine are characteristic. MRI can early detect the conditions, which is of important clinical significance in improving the prognosis of the patients.