RESUMO
OBJECTIVE: To evaluate the visualization of gallbladder stones on susceptibility-weighted imaging (SWI). MATERIALS AND METHODS: Imaging data from 47 patients who underwent clinically indicated cholecystectomy was reviewed. Breath-hold SWI was added to the magnetic resonance imaging protocol and magnitude and phase data was reviewed for gall-stones visualization. Phase signature, that is, diamagnetic, paramagnetic, or mixed, was also noted in the stones. Magnetic susceptibility value of surgically extracted gallstones were imaged ex vivo (n = 37). RESULTS: In 45 of 47 cases, gallstones were surgically confirmed. In 43 cases, gallstones were visualized in the SWI. In 1 case, although routine imaging failed, stones were visualized on SWI. In 29 diamagnetic, 7 paramagnetic and 9 cases mixed phase were seen. In an ex vivo study, magnetic susceptibility of stones was found ranging between -0.102 and -0.916 ppm for diamagnetic and 0.203 and 486 ppm for paramagnetic stones. CONCLUSIONS: Gallbladder stones can be visualized with SWI and may be added to the routine magnetic resonance imaging protocol for its evaluation.
