title: MR liver imaging and cholangiography in the presence of surgical metallic clips at 1.5 and 3 Tesla.
abstract: To evaluate whether clips from prior cholecystectomy impair image quality during magnetic resonance cholangiography (MRC) at 3 Tesla (T) compared with 1.5 T, surgical clips were embedded in a gel phantom and positioned at predefined distances from a fluid-filled tube designed to simulate the bile duct. The maximum clip distance was noted where susceptibility artifacts obscured the fluid-filled tube at 1.5 T and 3 T. Susceptibility artifact size was calculated for each sequence within each magnet class. In vivo analysis included 42 patients postcholecystectomy who underwent MRC at either 1.5 T or 3 T. In vitro, mean area of susceptibility artifacts was 104 mm2 on 3-T and 75 mm2 on 1.5-T MR imaging (MRI). While surgical clips within a 2-mm range impaired visualization of the fluid-filled tube on 1.5-T MRI, this range increased to 4 mm on 3-T MRI. In vivo, MRC image quality was impaired by susceptibility artifacts in three of 21 cases at 3 T and in two of 21 cases at 1.5 T. Overall, biliary pseudo-obstructions due to susceptibility artifacts from cholecystectomy surgical clips were not substantially more common on 3-T MRC in clinical practice, and patients with a history of prior cholecystectomy should not be excluded from a 3-T MRC.
authors.affiliation: Department of Radiology, Duke University Medical Center, Box 3808, Duke North--Room 1417, Erwin Road, Durham, NC, 27710, USA. elmar.merkle@duke.edu
authors.forename: Elmar M
authors.initials: EM
authors.lastname: Merkle
authors.forename: Brian M
authors.initials: BM
authors.lastname: Dale
authors.forename: John
authors.initials: J
authors.lastname: Thomas
authors.forename: Erik K
authors.initials: EK
authors.lastname: Paulson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016477:Artifacts; D001649:Bile Duct Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging; D049448:Cholangiopancreatography, Magnetic Resonance; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008670:Metals; D008875:Middle Aged; D019047:Phantoms, Imaging; D011859:Radiography; D013525:Surgical Instruments
chemical_list: D008670:Metals