Purpose: This review aims to sum up current knowledge on the sensitivity and specificity of ultrasound features suggestive of acute pelvic inflammatory disease (PID).
Methods: A PubMed database search was undertaken, using the MeSH terms "(pelvic inflammatory disease or salpingitis or adnexitis) and ultrasonography". We included original articles evaluating the performance of vaginal ultrasound in detecting acute PID.
Results: Seven articles were selected, including between 18 and 77 patients each. The golden standard used was laparoscopy/endometrial biopsy in six studies and mostly clinical evaluation in one. "Thick tubal walls" proved to be a specific and sensitive ultrasound sign of acute PID, provided that the walls of the tubes can be evaluated, i.e., when fluid is present in the tubal lumen (100 % sensitivity). The cogwheel sign is also a specific sign of PID (95-99 % specificity), but it seems to be less sensitive (0-86 % sensitivity). Bilateral adnexal masses appearing either as small solid masses or as cystic masses with thick walls and possibly manifesting the cogwheel sign also seems to be a reasonably reliable sign (82 % sensitivity, 83 %specificity). Doppler results overlap too much between women with and without acute PID for them to be useful in the diagnosis of acute PID, even though acutely inflamed tubes are richly vascularized at color Doppler.
Conclusions: Even though the results of our review suggest that transvaginal ultrasound has limited ability to diagnose acute PID, it is likely to be helpful when managing women with symptoms of acute PID, because in some cases the typical ultrasound signs of acute PID can be detected.