MR小肠造影前口服等渗甘露醇时间的探讨

Study of the Optimization Time for Taking Oral Isosmotic Mannitol in Magnetic Resonance Imaging Enterography Examination

目的:探讨选择口服等渗甘露醇在MR小肠造影效果的最佳时间。方法:对20例志愿者者行MR小肠造影,随机平均分两组:第一组检查前30min,第二组检查前45 min匀速口服2.5%等渗甘露醇2000ml做为肠道对比剂。MR扫描前1min肌注山莨菪碱20 mg抑制肠蠕动。扫描序列包括:(1)平扫:冠状面快速进动真稳态采集序列2D FIESTA,单次激发快速自旋回波(SSFSE)和快速扰相梯度回波(FSPGR);(2)增强:冠状面和横断面LAVA序列。记录患者小肠充盈效果,以差、优良等级评估,将MR小肠造影诊断结果与肠镜及临床诊断相对照。结果:20例(100%)回肠和空肠远段充盈效果优良。第一组呼吸运动伪影、肠蠕动伪影为1例,其余9例空肠近段充盈效果优良,图像可诊断率90%,诊断结果与病理或小肠镜相符7例,正确率77.8%(7/9);第二组4例空肠近段充盈良好,6例充盈效果差,其中呼吸运动伪影、肠蠕动伪影为1例,图像可诊断率40%,诊断结果与病理或小肠镜相符3例,正确率75%(3/4)。结论:在MR小肠造影前30min较检查前45min口服等渗甘露醇溶液小肠充盈效果更佳,口服等渗甘露醇法MR小肠造影是易行、可靠的小肠检查方法。

Purpose： To discuss the optimization time for oral isosmotic mannitol before MR enterography of small bowel. Methods： Twenty volunteers were received MR small intestine enterography, who were divided into two groups randomly： 30 min or 45 min before the examination, 2000 ml 2.5% isosmotic mannitol solution were taken continuously as a intraluminal contrast media, and 20 mg mountain scopolamine were received lmin before the MR exam to reduce small-bowel peristalsis. MRI sequences included： true steady-state acquisition sequence of 2D FIESTA, fat-saturated unenhanced coronal T2-weighted single-shot FSE （SSFSE）, T1 weighted coronal fast spoiled gradient echo （FSPGR）, and coronal and transverse post-enhanced LAVA sequence. The side effects were recorded and the image quality was graded as bad, good or excellent. The results between MR enterography and the surgical, pathological or clinical results were compared. Results： MR enterography was excellent with good filling in ileum and distal jejunum in all patients. The ileum and jejunum were with excellent filling in 9 patients （90%） in group 1, 90% of the images could be used to diagnose, of which, 7 case＇s diagnosis was in consistent with pathology or small intestine endoscope results, with the accuracy rate of 77.8%; Proximal jejunum was with good filling in 4 case （40%） and bad filling in the other 6 patients （60%） in group 2, 40% of the images could be used to diagnose, of which, 3 cases were in consistent with the pathology or small intestine endoscope results, with the accuracy rate of 75%; 2 cases were with respiratory motion mannitol artifacts or peristalsis artifacts. Conclusion： For the better small intestine filling, taking oral isosmotic 30min before MR enterography is better than that taking 45min before. MR enterography with oral isosmotic mannitol is a feasible and dependable method to diagnose small bowel disease.