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.

Body and Cardiovascular MR Imaging at 3.0 T

“…However, for most body and cardiovascular applications, greater susceptibility creates undesirable image distortions and signal loss-for example, in regions such as bowel-gas and cardiac-lung interfaces and around implanted metallic clips (12) or prostheses (Fig 1).…”

Assessment of MRI issues at 3-Tesla for metallic surgical implants: findings applied to 61 additional skin closure staples and vessel ligation clips

“…Metallic implants potentially pose hazards or problems for patients referred to magnetic resonance imaging (MRI) [2-11]. To ensure patient safety, in vitro test methods are utilized to characterize various MRI issues for a given implant or device [3-12].…”

MR Cholangiopancreatography: 1.5T versus 3T

“…To assess the extent of susceptibility artifacts from surgical clips from prior cholecystectomy at 3T, our group conducted an in vitro and in vivo study [35]. In the in vitro portion of the study, susceptibility artifacts were larger at 3T compared with 1.5T for two-dimensional, dual-echo, in-and opposedphase T1-and T2-weighted MRCP sequences, with the differences being statistically significant.…”

“…Increased susceptibility artifacts at higher magnetic field strengths can cause impaired image quality of MRCP examinations at 3T [35]. These artifacts usually are caused by gas, metal implants, surgical debris, or physiologic or pathologic conditions accompanied by iron deposition, such as hemosiderosis and hemochromatosis [36,37].…”