Needle localization in MR-guided biopsy and aspiration: effects of field strength, sequence design, and magnetic field orientation.

Abstract

Specific measurements differed with field strength, but needle tip localization within 1 mm was obtained at both 0.2 and 1.5 T with the appropriate frequency-encoding direction, pulse sequence, and imaging parameters. Orientation of the needle parallel to the magnetic field significantly reduced the apparent width of the needle at both field strengths but also decreased the accuracy of needle tip position localization.