Radiologic evaluation of structure and function of the sphincter of Oddi

An array of functional and morphologic disorders occur in and around the sphincter of Oddi, and accurate diagnostic evaluation frequently uses a variety of radiographic imaging modalities. Although endoscopic manometry has become the cornerstone in diagnosing functional disorders of the sphincter of Oddi, imaging at endoscopic retrograde cholangiopancreatography (ERCP) is used concurrently to evaluate sphincteric function and to exclude a variety of morphologic disorders that may occur in the sphincteric region as well. Imaging technique and interpretation at ERCP as it pertains to the sphincter of Oddi is emphasized. Cross-sectional imaging studies such as computed tomography and ultrasound may be performed in the initial screening of patients with suspected sphincter of Oddi dysfunction and are primarily useful in detecting or excluding morphologic pathology occurring near the sphincter of Oddi. Noninvasive functional evaluation of the sphincter of Oddi, including fatty meal sonography and quantitative hepatobiliary scintigraphy, has been described and may be used in the initial evaluation and screening of patients with suspected sphincter of Oddi dysfunction.