Diffusion-weighted Imaging For The Detection Of Symptomatic Meckel's Diverticulum With MR-Enterography In Pediatric Patients

Objective1.To retrospectively investigate the values of MRE for detecting symptomatic Meckel's diverticulum in pediatric patients.2.The aim of this study was to retrospectively evaluate the diagnostic performance of diffusion-weighted imaging(DWI)in MR-enterography(MRE)to detect symptomatic Meckel's diverticulum(MD)in paediatric patients.Materials and Methods1.We retrospectively selected from our MR database patients who underwent MR-enterography between June 2014 and September 2015 for suspected MD after negative or inconclusive upper sonography or scintigraphy or for whom the referring physician wanted to exclude presence of an Meckel's diverticulum.There were 13 males and 3 females,with a mean age of 3.3 years of age ranging from 0.4 to 8.2 years old,The first symptom included unexplained gastrointestinal bleeding,abdominal pain,small-bowel obstruction,intussusception,vomiting and fever.Two experienced radiologists determined the diverticulum 's location?shape?contents and peripheral structural abnormalities.2.2014 and May 2016 for suspected MD after a negative or inconclusive upper sonography or scintigraphy or for whom the referring physician needed to exclude the presence of a MD.MRE of thirty-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.Results1.MD were diagnosed by MRE in all children,13 MD and 3 intestinal duplication cysts were pathologically confirmed,the accuracy of MRE was 81.3%(13/16).The diverticulum 's location: the right lower quadrant in 2 cases,around the navel in 4 cases,the left lower quadrant in 4 cases,the middle quadrant in 2 cases and pelvic cavity in 1 case.The diverticulum 's shape: diverticulum as a blind-ending fluid-filled or gas-filled structure in 11 cases,and a solid-appearing mass in 2 cases.The wall of the diverticulum showed a focus of restricted diffusion in 12 cases and mural enhancement comparable with that of adjacent small bowel in 12 cases,Interruption of the wall continuity in 1 cases.Hemorrhage in diverticulum appearing as T1 WI signal hyperintensity and/or T2 WI signal hypointensity in 2 cases,Extravasation of intravascular contrast medium into the gastrointestinal tract due to active bleeding from a Meckel diverticulum in 2 cases.Peripheral structural abnormalities included soft-tissue stranding,adjacent mesenteric stranding and enhancement,free fluid,small-bowel obstruction and prominent lymph nodes.2.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)and 45.7 % [95 % CI: 28.8 %-63.3 %](16/35),respectively.With the addition of DWI the above results resulted 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)and 71.4 %[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 sensitivity or accuracy.Conclusions1.MRE was more sensitive for symptomatic Meckel's diverticulum than sonography and scintigraphy.MRE may play an important diagnostic role going forward in the setting of suspected symptomatic Meckel diverticula,particularly given its lack of ionizing radiation.2.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.