Pneumobilia: where to look for on hepatic MR imaging?
The presence of pneumobilia is a particular problem in magnetic resonance cholangiopancreatography (MRPC) and may create an appearance that can be mistaken for intraductal stones. Compared with biliary stones, however, pneumobilia causes a susceptibility artifact on hepatic MR imaging and appears as a signal void on a dual echo gradient MR sequence, such as the T1-weighted in-phase and opposed-phase gradient echo sequence. This susceptibility artifact is more pronounced on the gradient echo image with the longer echo time due to the continued decay of the transverse magnetization. Besides identification of hepatic steatosis, the double echo approach is particularly helpful in identification of pneumobilia.
Merkle
Elmar M
EM
Department of Radiology, Duke University Medical Center, Duke North, Room 1417 Erwin Road, P.O. Box 3808, Durham, NC, 27710, USA. elmar.merkle@duke.edu
D016477:Artifacts; D001660:Biliary Tract Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging; D049448:Cholangiopancreatography, Magnetic Resonance / Q000379:methods*; D006801:Humans; D014057:Tomography, X-Ray Computed