Sonographic findings in acute puerperal endometritis: The hypoechoic rim sign and endomyometrial junction indistinctness

Abstract

Purpose: To evaluate the accuracy of the sonographic subserosal hypoechoic rim sign and endomyometrial junctional indistinctness in identifying patients with acute endometritis during the puerperal period.

Methods: Radiologic coding identified the ultrasound scans of all patients presenting to Auckland City Hospital between January 2014 and February 2016 who were diagnosed clinically as having acute endometritis during the post-partum or post-abortion period. After exclusion criteria were applied, the ultrasound scans of 31 patients with acute endometritis and 32 healthy controls were randomised and anonymised. Images were reviewed retrospectively by two independent reviewers to identify the presence of these signs.

Results: The average sensitivity and specificity for readers identifying the subserosal hypoechoic rim sign in patients with acute endometritis were 71% and 92%, respectively. Interobserver reliability was good with an average kappa score of 0.63. Average sensitivity and specificity for endomyometrial junctional indistinctness were 79% and 72%, respectively, with good interobserver correlation (average kappa score 0.65). When both signs were either present or absent together, average sensitivity improved to 80.5% and average specificity was 91.7%.

Conclusion: We describe two new sonographic signs for puerperal endomyometritis that could improve the utility of ultrasound in the accurate and timely diagnosis of this condition.

Keywords: endometritis; endomyometritis; hypoechoic rim; junctional indistinctness; puerperal; ultrasound.

Figure 1

(a) Transvaginal sagittal image of the uterus in 32‐year‐old patient with acute endometritis 14 days after vaginal delivery demonstrates the subserosal hypoechoic rim and endomyometrial junctional indistinction. (b) Transvaginal sagittal image of the uterus in a 30‐year‐old female 3 days after surgical termination of pregnancy who was scanned to rule out RPOC demonstrates a small amount of debris in the endometrial cavity but the endomyometrial junction is well defined and no subserosal hypoechoic rim was identified by either reader.

Figure 2

(a) Transvaginal sagittal ultrasound image of a 41‐year‐old female with acute endometritis 14 days after vaginal delivery shows endomyometrial junction indistinctness as well as the subserosal hypoechoic rim sign. (b) Sagittal transvaginal ultrasound image of a 31‐year‐old female scanned to examine for RPOC following miscarriage demonstrates good definition of the endomyometrial junction and absence of the hypoechoic rim sign.