Utility of Pelvic Ultrasound with Negative Computed Tomography in Adult Females.

INTRODUCTION

Emergency physicians must consider ovarian torsion in all biologically female patients who present to the emergency department (ED) with abdominal pain. A misdiagnosis can result in detrimental outcomes, such as loss of an ovary. Female patients who present to the ED for evaluation of their abdominal pain may have a computed tomography (CT) or pelvic ultrasound performed to further evaluate for concerning pathology. Our objective in this study was to describe the occurrence of critical or emergent findings on pelvic ultrasound not identified on a concurrent or previously performed CT of the abdomen and pelvis.

METHODS

We conducted a retrospective chart review of ED visits from January 1-December 31, 2021 at a large, suburban, academic medical center. Eligible patients were adult females (≥ 21 years of age) who had a CT of the abdomen and pelvis and pelvic ultrasound, with the CT ordered either before or simultaneously with the pelvic ultrasound. We excluded from the study CTs with abdominal or pelvic pathology. The primary outcome measure was to determine the occurrence of pelvic ultrasounds without acute pathology with a negative CT. The secondary outcome measure was to identify non-emergent findings on pelvic ultrasound with a negative CT.

RESULTS

Of 281 eligible ED visits, 172 patients (61.2%) had gynecologic pathology on CT and 60 patients (21.4%) had other pathology on CT. The mean age was 43.3 years (SD 16.4). Forty-nine patients (17.4%) had unremarkable CT results. Of those, 39 patients (79.6%; 95% CI, 65.7-89.8%) had a normal ultrasound; three patients (6.1%; 95% CI,1.3-16.9%) had an ovarian cyst; six patients (12.2%; 95% CI, 4.6-24.8%) had other non-emergent results; and one patient (2.0%; 95% CI, 0.05-10.9%) had a 10- by 11-mm ovarian mass on ultrasound. In patients with unremarkable CTs, 48 (98.0%; 95% CI, 89.1-99.9%) also had normal or not clinically significant ultrasound results. No definite ovarian torsions were diagnosed on ultrasound after a negative CT.

CONCLUSION

Obtaining a pelvic ultrasound following an unremarkable CT of the abdomen and pelvis may not produce additional clinically relevant results in an emergency setting.