We thank our radiology colleagues for their interest in our research and for their comments on the value of the physical exam in the evaluation of pregnant women with suspected appendicitis. We certainly agree that clinical judgment should inform the decision to proceed with imaging in these cases. Our cohort included only pregnant women who underwent magnetic resonance imaging (MRI) for suspected appendicitis that could not be ruled out clinically. While some women may have proceeded to surgery without imaging based on their clinical presentation, clinicians are almost always justified in obtaining preoperative imaging in pregnant women with suspected appendicitis, and this is the accepted standard in our institution. The limited utility of clinical judgment alone in reliably diagnosing appendicitis during pregnancy has been extensively reported in the literature in the form of unacceptably high negative laparotomy rates. Further, a hemorrhagic corpus luteum or degenerating fibroid can certainly mimic the abdominal exam findings typical of acute appendicitis; so achieving a final diagnosis of an ovarian mass or uterine fibroids on imaging does not necessarily constitute a failure of clinical acumen.

In our study, comparisons between MRI and ultrasound refer only to imaging of the appendix. We certainly do not mean to say, nor did we, that MRI should replace ultrasound as the initial imaging modality of choice to assess the uterus and adnexa, and we wholly agree that a basic pelvic ultrasound to confirm intrauterine location of a pregnancy should be performed before proceeding with other imaging studies. We want to emphasize that this study was performed in an institution with a high rate of ectopic pregnancy, and the cases of ectopic pregnancy diagnosed on MRI within this cohort represent rare exceptions to the number of ectopic pregnancies appropriately diagnosed on pelvic ultrasound. Ultrasound is also an excellent first-line test for visualizing relatively accessible structures such as the kidneys and gallbladder, regardless of the stage of pregnancy ; however, limited ultrasounds of the appendix have been shown to have poor diagnostic capabilities in pregnant women.

Evidence-based medicine is great because it evolves. New scientific evidence helps medicine improve. Guidelines should change and improve with the science, and the suggestion that practice should conform to guidelines based on old evidence is misguided, to say the least. While the authors did not cite any literature in support of their opinion, we encourage them to use the best medical evidence available to guide best practice.