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[Retrospective 5-year analysis of MR-guided biopsies in a low-field MR system].

PURPOSE
The purpose of this study was to evaluate the safety and clinical value of MR-guided biopsies in an open 0.2 T low-field system.


MATERIALS AND METHODS
A total of 322 patients with suspicious lesions of different body regions were biopsied in a low-field MRI system (0.2 T, Concerto, Siemens). The procedures were guided using T 1-weighted Flash sequences (TR/TE = 100/9; 70 degrees). The lesions were repeatedly biopsied using the coaxial technique with a 15-gauge (diameter 2 mm) puncture needle. Complications and biopsy findings were analyzed retrospectively.


RESULTS
In all cases the biopsy procedures were successfully performed with MR guidance. In 298 patients diagnosis was able to be confirmed on the basis of the probes. The clinical follow-up showed that in 24 patients the lesions were missed by MR-guided biopsy. From this a sensitivity of 86%, a specificity of 87% and an accuracy of 93% were calculated. In two patients major complications were observed (morbidity rate 0.6 %).


CONCLUSION
MR-guided biopsy can be performed safely and precisely in a low-field MR system and are a supplement to US or CT-guided biopsies.