扩散加权成像结合MR小肠造影诊断儿童美克尔憩室合并症

Diffusion-Weighted Imaging for the Detection of Symptomatic Meckel’s Diverticulum with MR-Enterography in Pediatric Patients

目的回顾性分析扩散加权成像（DWI）结合MR小肠造影（MRE）在儿童美克尔憩室（MD）合并症中的诊断价值。方法搜集经超声、核素检查或临床体征怀疑MD合并症的35例患儿的临床及MRE资料。两名儿科影像医师通过共同分析阅片确定憩室的存在。设计4种序列组合阅片：（1）标准序列组（单次激发快速自旋回波序列和二维平衡稳态自由进动序列）;（2）标准序列＋DWI组;（3）标准序列＋增强扫描（CE-MR）组;（4）标准序列＋DWI＋CE-MR组。结果手术病理证实MD 20例,标准序列组诊断敏感性、特异性、阳性预测值、阴性预测值及准确性分别为：40.0%（95%CI：19.1%-63.9%）（8/20）;53.3%（95%CI：26.6%-78.7%）（8/15）;53.3%（95%CI：26.6%-78.7%）（8/15）;40.0%（95%CI：19.1%-63.9%）（8/20）;45.7%（95%CI：28.8%-63.3%）16/35）。标准序列＋DWI序列后分别为85.0%（95%CI：62.1%-96.7%）（17/20）;53.3%（95%CI：26.6%-78.7%）（8/15）;70.8%（95%CI：48.9%-87.3%）（17/24）;72.7%（95%CI：39.0%-93.9%）（8/11）;71.4%（95%CI：53.6%-58.3%）（25/35）,诊断敏感性显著提高（40.0%vs 85.0%,P=0.012）。标准序列＋CE-MR组和标准序列＋DWI组的诊断敏感性及准确性无统计学意义。结论相对于标准序列组,DWI序列明显提高了MD诊断敏感性。因此,有望替代屏气增强扫描序列,应用于不能有效屏气的低年龄组患儿。

Objective The aim of this study was to retrospectively evaluate the diagnostic performance of diffusionweighted imaging （DWI） in MR-enterography （MRE） to detect symptomatic Meckelg diverticulum （MD） in paediatric patients. Methods The clinical and MRE data of 35 children suspected of having MD comorbidities fi＇om our hospital [＇rom July 2014 to May 2016 were collected by ultrasound, nuclide examination or clinical signs in our hospital. MRE of thiity- five children were blindly analyzed by two pediatric radiologists to evaluate the presence of MD and decisions were made by consensus. The following image sets were examined and compared： （ 1 ） ＂standard＂ sequences （ Single-shot turbo spin- echo and Balanced turbo field echo sequences） , （2） ＂standard＂ ＋ DWI-MR, （3） ＂standard＂ ＋ contrast material-enhanced T1-weighted sequences （CE-MR）,and （4） ＂standard＂ ＋ DWI-MR ＋ CE-MR. Results Twenty MDs were pathologically confirmed. The detection of symptomatic MD via standard MRI resulted in the following sensitivity, specificity, PPV, NPV and accuracy results： 40.0 % （95% CI： 19.1% -63.9%） （8/20）,53.3 % （95% CI： 26.6% -78.7%） （8/15）, 53.3 % （95 %CI： 26.6% -78.7%） （8/15）,40.0 % （95% CI： 19.1% -63.9%） （8/20） and45.7 % （95% CI： 28.8% -63.3% ） （16/35） ,respectively. With the addition of DWI the above results resulted in the following： 85.0 % （95 % CI：62.1% -96.7%） （17/20）,53.3% （95 % CI：26.6% -78.7%） （8/15）,70.8% （95% CI：48.9% -87.3%） （17/24）,72.7 % （95% CI： 39.0%-93.9%） （8/11）and71.4% （95% CI： 53.6%-58.3%） （25/ 35）. Diagnostic sensitivity （40.0% vs. 85.0% ,P =0. 012） was significantly increased by adding DWI to standard MRI. The two methods （standard MRI ＋ DWI and standard MRI ＋ CE-MR） showed no significant difference in diagnostic sensi- tivity or accuracy. Conclusion DWI improved the diagnostic sensitivity of symptomatic MD compared to standard MRI. These advantages might allow MRE application without intravenous contrast material in young children who cannot cooperate with breath-hold instructions necessary to perform post contrast T1-weighted sequences.