title: Pelvic ultrasound immediately following MDCT in female patients with abdominal/pelvic pain: is it always necessary?
abstract: To determine the added value of reimaging the female pelvis with ultrasound (US) immediately following multidetector CT (MDCT) in the emergent setting. CT and US exams of 70 patients who underwent MDCT for evaluation of abdominal/pelvic pain followed by pelvic ultrasound within 48 h were retrospectively reviewed by three readers. Initially, only the CT images were reviewed followed by evaluation of CT images in conjunction with US images. Diagnostic confidence was recorded for each reading and an exact Wilcoxon signed rank test was performed to compare the two. Changes in diagnosis based on combined CT and US readings versus CT readings alone were identified. Confidence intervals (95%) were derived for the percentage of times US reimaging can be expected to lead to a change in diagnosis relative to the diagnosis based on CT interpretation alone. Ultrasound changed the diagnosis for the ovaries/adnexa 8.1% of the time (three reader average); the majority being cases of a suspected CT abnormality found to be normal on US. Ultrasound changed the diagnosis for the uterus 11.9% of the time (three reader average); the majority related to the endometrial canal. The 95% confidence intervals for the ovaries/adnexa and uterus were 5-12.5% and 8-17%, respectively. Ten cases of a normal CT were followed by a normal US with 100% agreement across all three readers. Experienced readers correctly diagnosed ruptured ovarian cysts and tubo-ovarian abscesses (TOA) based on CT alone with 100% agreement. US reimaging after MDCT of the abdomen and pelvis is not helpful: (1) following a normal CT of the pelvic organs or (2) when CT findings are diagnostic and/or characteristic of certain entities such as ruptured cysts and TOA. Reimaging with ultrasound is warranted for (1) less-experienced readers to improve diagnostic confidence or when CT findings are not definitive, (2) further evaluation of suspected endometrial abnormalities. A distinction should be made between the need for immediate vs. follow-up imaging with US after CT.
authors.affiliation: Department of Radiology, Women's Imaging Division, New York University Medical Center, Tisch Hospital, 560 First Avenue, New York, NY 10016, USA. silaja.yitta@nyumc.org
authors.forename: Silaja
authors.initials: S
authors.lastname: Yitta
authors.forename: Elizabeth V
authors.initials: EV
authors.lastname: Mausner
authors.forename: Alice
authors.initials: A
authors.lastname: Kim
authors.forename: Danny
authors.initials: D
authors.lastname: Kim
authors.forename: James S
authors.initials: JS
authors.lastname: Babb
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Hecht
authors.forename: Genevieve L
authors.initials: GL
authors.lastname: Bennett
mesh_terms: D015746:Abdominal Pain / Q000000981:diagnostic imaging*; D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016001:Confidence Intervals; D003287:Contrast Media; D003937:Diagnosis, Differential; D003974:Diatrizoate Meglumine; D005260:Female; D005831:Genital Diseases, Female / Q000000981:diagnostic imaging*; D006801:Humans; D007472:Iohexol / Q000031:analogs & derivatives; D016015:Logistic Models; D008875:Middle Aged; D017699:Pelvic Pain / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014463:Ultrasonography
chemical_list: D003287:Contrast Media; D003974:Diatrizoate Meglumine; D007472:Iohexol; C038192:iopromide