E4927. Adnexal Torsion: Believe the CT
  1. Tyler Thornton; University of North Texas Health Science Center
  2. Joshua Baker; University of North Texas Health Science Center
  3. Jared Ivan; University of North Texas Health Science Center
  4. Ajay Prabhu; University of North Texas Health Science Center
  5. William Reese; Radiology Associates of North Texas
Adnexal torsion (AT) is the fifth most common gynecologic emergency. Torsion occurs when the adnexa, consisting of the ovary and fallopian tube, twists around itself, causing variable degrees of vascular compromise. Although the majority of AT occur in women of childbearing age, torsion can occur in female patients of all ages. Risk factors for torsion most notably include history of previous torsion and the presence of an adnexal mass, which has been shown to be present in as many as 46% of cases. The clinical presentation of AT most often includes severe abdominal/pelvic pain, often unilateral in nature, accompanied by nausea and vomiting. Additional clinical findings can include low-grade fever and adnexal fullness on physical examination, though these are not as common. Due to the nonspecific nature of these findings, AT diagnosis is challenging and often missed. The imaging recommendation for the diagnosis of AT has historically heavily favored ultrasound (US), due to its accessibility, capacity to identify blood flow with color and power Doppler, and safety profile. This recommendation often leans heavily on the concordance of decreased flow on doppler with torsion. However, flow often persists to varying degrees, even in the presence of torsion, and can lead to missed diagnoses or delayed treatment causing ovarian compromise. We present a case-based review of patients with surgically confirmed AT with their respective imaging. This review illustrates the utility of CT in the diagnosis of AT and presents common AT structural changes to assist the radiologist in making the diagnosis.

Educational Goals / Teaching Points
By the end of this presentation, the reader should develop an understanding of the anatomy and pathophysiology of ovarian/adnexal torsion. The reader should be able to identify common CT findings consistent with AT and appreciate its utility in the diagnosis and management of patients with AT. The reader should also understand the utility, limitations, and, at times, misleading findings of US in torsion diagnoses.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
The discussion of each case will present the pertinent clinical course and a review of pertinent CT findings, including adnexal enlargement, uterine deviation, thickened pedicle, whirl sign, and ovarian edema aiding in the diagnosis of AT. The reviewed cases will also demonstrate concomitant US findings as they contributed to patient management and identify US pitfalls. Representative CT and US images will be provided to illustrate findings.

AT is a relatively common and serious condition requiring prompt intervention. Radiologists should be able to readily identify common findings of torsion on CT and recognize the limitations and pitfalls of US in patient management.