鼻咽癌放疗后放射性脑干和脊髓损伤的磁共振表现

Magnetic Resonance Imaging Manifestations of Radiation Injury in Brain Stem and Cervical Spinal Cord of Nasopharyngeal Carcinoma Patients after Radiotherapy

背景与目的:鼻咽癌(nasopharyngealcarcinoma,NPC)放射治疗后脑干和颈髓放射性损伤的诊断相当重要。磁共振(magneticresonanceimaging,MRI)用于诊断鼻咽癌放疗后放射性脑损伤已有较多报道,但脑干和颈髓放射性损伤的MRI表现文献报道较少。本研究旨在分析鼻咽癌放疗后脑干和颈髓放射性损伤的MRI特征。方法:对60例鼻咽癌患者在放射治疗后6个月至5年内进行了MRI检查,MRI检查序列包括T1-weightedimage(T1WI)、T2-weightedimage(T2WI)、fluidattenuatedinversionrecovery(FLAIR);所有患者均做了MRI增强扫描。结果:6例为颈髓放射性损伤;54例为脑干放射性损伤,其中脑桥20例,桥脑基底部与延髓上段26例,中脑受累3例,延髓5例。病灶在MRI上T1WI表现为等信号和低信号,T2WI上为高信号,增强后病灶无强化者11例(18.3%),强化者49例(81.7%)。强化者有2种强化形式:均匀斑片状强化(21例,42.9%)和不均匀的既有环形又有斑片状的强化(28例,57.1%)。结论:MRI可以清晰地显示脑干和脊髓放射性损伤的病灶,结合病史可以确诊。

BACKGROUND & OBJECTIVE: It is very important to diagnose the radiation injury in brain stem and cervical spinal cord of patients with nasopharyngeal carcinoma (NPC) after radiotherapy. Magnetic resonance imaging (MRI) manifestations of radiation encephalopathy have been widely reported, while those of radiation injury in brain stem and cervical spinal cord have been seldom reported. This study was to analyze the MRI characteristics of radiation injury in brain stem and cervical spinal cord of patients with NPC after radiotherapy. METHODS: MRI was performed in 60 NPC patients 6 months to 5 years after radiotherapy. The imaging sequences included T1-weighted image (T1WI), T2-weighted image (T2WI), fluid attenuated inversion recovery (FLAIR). All patients received T1WI contrast-enhanced scanning. RESULTS: Of the 60 patients, 6 had lesions in cervical spinal cord, 54 had lesions in brain stem. Of the 54 cases of radiation injury in brain stem, most lesions located in pons (20 cases), basis pons and medulla oblongata (26 cases), others located in mesencephalon (3 cases), medulla oblongata (5 cases). All lesions showed hypo- or iso-intense signal on T1WI, and hyper-intense signal on T2WI. After contrast-enhanced scanning, 11 cases (18.3%) had no enhancement; 49 (81.7%) markedly enhanced with 21 cases (42.9%) of homogenous patchy enhancement, and 28 cases (57.1%) of hetergenerous ringed and patchy enhancement. CONCLUSION: MRI shows clearly the radiation injury in brain stem and cervical spinal cord of NPC patients after radiotherapy.