The technique of MRT aided abdominal drainage using an open low field magnet.

Purpose: To test the practicality of MRT-aided drainage using an open low field magnet and to report on the early clinical results. Methods: So far seven patients have been treated (four subphrenic abscesses, two psoas abscesses and one pancreatic pseudocyst). The planning of the approach and catheter insertion were carried out under MRT control (Magnetom Open, 0.2 T). Subsequent treatment was controlled by CT and fluoroscopy. Initial puncture was carried out with a non-magnetic 18 gauge Chiba needle. The drainage catheter was introduced by Seldinger's technique in six cases and with a trocar in one patient. Results: In all seven patients drainage could be started successfully. The design of the magnet and coils permitted adequate accessibility of the patient. There were no problems in visualising the puncture needle. Controlling the position of the catheter by MRT was, however, difficult. Conclusion: The first two steps in abscess drainage (planning the approach and inserting the catheter) can be carried out under MRT control. For further catheter control and observing the course of the disease we presently prefer CT or fluoroscopy.