Real-time magnetic resonance imaging-guided frameless stereotactic brain biopsy: technical note

Abstract

OBJECT The object of this study was to assess the feasibility, accuracy, and safety of real-time MRI-compatible frameless stereotactic brain biopsy. METHODS Clinical, imaging, and histological data in consecutive patients who underwent stereotactic brain biopsy using a frameless real-time MRI system were analyzed. RESULTS Five consecutive patients (4 males, 1 female) were included in this study. The mean age at biopsy was 45.8 years (range 29–60 years). Real-time MRI permitted concurrent display of the biopsy cannula trajectory and tip during placement at the target. The mean target depth of biopsied lesions was 71.3 mm (range 60.4–80.4 mm). Targeting accuracy analysis revealed a mean radial error of 1.3 ± 1.1 mm (mean ± standard deviation), mean depth error of 0.7 ± 0.3 mm, and a mean absolute tip error of 1.5 ± 1.1 mm. There was no correlation between target depth and absolute tip error (Pearson product-moment correlation coefficient, r = 0.22). All biopsy cannulae were placed at the target with a single penetration and resulted in a diagnostic specimen in all cases. Histopathological evaluation of biopsy samples revealed dysembryoplastic neuroepithelial tumor (1 case), breast carcinoma (1 case), and glioblastoma multiforme (3 cases). CONCLUSIONS The ability to place a biopsy cannula under real-time imaging guidance permits on-the-fly alterations in the cannula trajectory and/or tip placement. Real-time imaging during MRI-guided brain biopsy provides precise safe targeting of brain lesions.