Visualization of magnetic resonance-compatible needles at 1.5 and 0.2 Tesla

Purpose: For two types of passively visualizable magnetic resonance (MR)-compatible needles, the size of susceptibility artifacts was investigated at 0.2 and 1.5 Tesla (T) and assessed regarding their suitability for needle visualization. Methods: Phantom trials were performed using T1-weighted spin echo (SE), turbospin echo (TSE) and gradient echo (GE) sequences and different angles β between the needles and the main magnetic field (B₀). Results: Depending on the needle angle β and the applied pulse sequence, we found artifact diameters of 0-9.7 mm employing SE, of 1.7-9.4 mm employing TSE, and of 1.4-20.6 mm employing GE at 1.5 T. At 0.2 T, we found artifact diameters of 0-5.7 mm employing SE, of 0-6.3 mm employing TSE, and of 0- 11.3 mm employing GE. Conclusion: Comparing artifact sizes at 1.5 T and 0.2 T, low field strength is superior for passive visualization of the needles tested-especially if GE imaging is performed.