Magnetic resonance imaging as the first diagnostic imaging modality forpregnant women with suspected acute appendicitis

ABSTRACT

Objective@#The sensitivity of ultrasonography is poor in pregnant women with suspected appendicitis. Additional magnetic resonance imaging (MRI) is usually required, which can delay the diagnosis and surgical intervention. We hypothesized that the use of MRI as the first diagnostic tool could increase the detection rate and reduce the time for diagnosis. Therefore, we sought to investigate the diagnostic yield of ultrasonography vs. MRI and the emergency department length of stay (ED-LOS) of pregnant women with suspected appendicitis. @*Methods@#This was a retrospective, observational study in the ED of a single tertiary teaching hospital from January 2010 to December 2017. Patients who underwent ultrasonography or MRI or both were enrolled. The primary outcome was the diagnostic yield of acute appendicitis and the ED-LOS. The secondary outcome was the proportion of complicated appendicitis cases. @*Results@#A total of 145 pregnant women were enrolled (ultrasonography only, n=73; MRI only, n=26; both ultrasonography and MRI, n=46). The diagnostic yield was 23.5% (28/119) by ultrasonography and 79.2% (57/72) by MRI. The diagnostic yield of ultrasonography was significantly lower than that of MRI, especially in the second and third trimesters. The ED-LOS was significantly longer in the ultrasonography plus MRI group than that in the MRI-only group (9 hours vs. 6 hours, P=0.002). @*Conclusion@#In this study, MRI had a higher diagnostic yield than ultrasonography and can reduce the time to diagnosis. Thus, MRI should be considered as the first diagnostic tool for suspected acute appendicitis in pregnant women.