[Interactive stereotaxic interventions in superconducting, open 0.5-Tesla MRI tomography]. / Interaktive, stereotaktische Interventionen im supraleitenden, offenen 0.5-Tesla-MR-Tomographen.

ABSTRACT

PURPOSE: Evaluation of an interactive, stereotactic biopsy device integrated in an open superconductive 0.5 tesla MR-scanner with a vertical gap. MATERIAL AND METHODS: In addition to "in-vitro" experiments performed on a plexiglas phantom with holes of varying diameters (5-20 mm) biopsies on eleven patients (7 women, 4 men; average age 55 years) were performed in the interventional MR-system. Lesions in the abdomen (n = 6), muscle (n = 1), thyroid (n = 3) and breast (n = 1) were targeted with 18-20 G aspiration biopsy needles of 5-15 cm length. The intervention was interactively guided by a fast T1-weighted 2-D gradient echo sequence. RESULTS: All of the 15 and 20 mm holes of the phantom, but only 83% of the 10 and 5 mm holes were hit. No complications occurred during the MR-guided patient procedures. All lesions (mean size 3.5 cm, distance from the skin 2 cm to 10 cm) were biopsied successfully. The fast image acquisition in combination with the stereotactic technique enables interactive control of the needle. CONCLUSIONS: Stereotactic, interactively controlled biopsies in the interventional MR are technical feasible. However, the range of meaningful indications for MR-guided biopsies is limited.