Laparoscopic surgery in a 0.5-t interventional magnetic resonance unit.

BACKGROUND: Intraoperative imaging using magnetic resonance imaging (MRI) is now possible in interventional MR (IMR) units. Magnetic resonance imaging has potential advantages over other methods used to guide surgery. These advantages include visualization of structures deep to the two-dimensional endoscopic image and clarification of surgical anatomy. This study investigates the feasibility of laparoscopic surgery with intraoperative imaging within an IMR unit.
METHODS: The procedures were performed in a 0. 5-T General Electric IMR scanner. Surgical ergonomics and intraoperative imaging were investigated by performing 10 laparoscopic cholecystectomies on porcine livers in a simulator using magnet-safe laparoscopic instruments and an ultrasonic scalpel for dissection. Intraoperative MR cholangiography (MRC) was performed using T2-weighted fast-spin-echo (FSE) and single-shot fast-spin-echo (ssFSE) techniques with maximal intensity projection (MIP) reconstruction. Two laparoscopic cholecystectomies then were performed on human patients with intraoperative MRC using similar techniques.
RESULTS: The simulated procedures allowed the development of surgical techniques appropriate to this environment. Both FSE and ssFSE produced reasonable quality intraoperative images. Both patient procedures were performed without complication. The FSE imaging was of poor quality. However, ssFSE produced intraoperative images of the gallbladder with partial visualization of the extrahepatic biliary tree.
CONCLUSIONS: Laparoscopic surgery in an IMR unit is technically possible. Currently, intraoperative MRC is difficult, and FSE imaging is very subject to movement artifact. However, the faster ssFSE, with further development, may be a useful technique for intraoperative imaging of the biliary tree during MR-guided surgery.