An in vitro study at low field for MR guidance of a biopsy needle

The aim of this study is to demonstrate in vitro that low field strength can be used for MR interventional procedures. At 0.1 T, we developed 3D, T1-, and T2-weighted fast steady state sequences and measured the artifact created by an MR biopsy needle (22 gauge, 0.7 mm diameter) on a bicompartmental phantom. The artifact generated by the needle placed perpendicular to B0 did not exceed 3.6 mm for 3D steady state sequences and acquisition times reaching 1.5 s. Corresponding artifacts at higher field strength were 7.6 mm for 0.5 T and 8.6 mm for 1 T. Low field MRI proved to be potentially adaptable for the guidance of MR biopsy needles.