CT and ultrasound are both valuable first-line cross-sectional imaging tools to detect the cause of acute pelvic pain in non-pregnant women and the need for surgery in these patients, according to a new study by researchers from the University of Washington Harborview Medical Center in Seattle, WA.

For the study, the researchers analyzed 157 women who were recommended for imaging because of acute pelvic pain. In 71 and 86 cases, respectively, an abdomen/pelvis CT or a pelvic ultrasound was performed first. The researchers found that abnormal findings were described in 70% and 65% of the initial CTs and ultrasounds, respectively. The final diagnosis was obtained through CT or ultrasound in 80% of cases. In predicting the need for surgery, the sensitivity and positive predictive value for both CT and US were above 0.80. The specificity and negative predictive value were greater than 0.97.

According to the researchers, the two main purposes of the study were to determine if one imaging method was better and if CT and ultrasound were helpful in the diagnosis of acute pelvic pain for those patients that the clinical staff referred for imaging. “If a study has a low yield of positive findings, then some radiologists feel that too many patients are being imaged and that the clinical threshold for ordering has been lowered too much,” said Dawn Hastreiter, MD, PhD, lead author of the study.

“Our findings show that patients presenting to our institution are probably not being over-imaged with our current imaging referral protocols. Our positivity rate could be used as a comparison standard for other institutions to determine if they are overusing imaging. In addition, one might conclude from our study that pelvic ultrasound and CT are nearly equally effective in aiding in the diagnosis of acute pelvic pain and that performing both imaging techniques in an emergency setting could be reserved for unclear cases,” said Dr. Hastreiter.

The full results of the study will be presented on Monday, May 1, 2006 during the American Roentgen Ray Society Annual Meeting in Vancouver, BC.

About ARRS
The American Roentgen Ray Society (ARRS) was founded in 1900 and is the oldest radiology society in the U.S Radiologists from all over the world attend the ARRS Annual Meeting to take part in instructional courses, scientific paper presentations, symposiums, new issues forums and scientific and commercial exhibits related to the field of radiology. The ARRS is named after Wilhelm Ro"entgen, who discovered the x-ray in 1895.