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

Area of Science:

• Medical Imaging
• Biomedical Engineering
• Materials Science

Background:

• Accurate visualization of MR-compatible needles is crucial for precise interventions.
• Susceptibility artifacts can obscure needle placement, impacting procedure safety and efficacy.
• Understanding artifact behavior across different magnetic field strengths and imaging sequences is essential.

Purpose of the Study:

• To investigate the size of susceptibility artifacts generated by two types of MR-compatible needles.
• To evaluate artifact size at 0.2 Tesla (T) and 1.5 T magnetic field strengths.
• To determine the suitability of these needles for passive visualization under varying MR conditions.

Main Methods:

• Phantom studies were conducted using two passively visualizable MR-compatible needles.
• T1-weighted spin echo (SE), turbospin echo (TSE), and gradient echo (GE) pulse sequences were employed.
• Artifact diameters were measured at different angles (beta) relative to the main magnetic field (B0) at 0.2 T and 1.5 T.

Main Results:

• At 1.5 T, artifact diameters ranged from 0-9.7 mm (SE), 1.7-9.4 mm (TSE), and 1.4-20.6 mm (GE).
• At 0.2 T, artifact diameters ranged from 0-5.7 mm (SE), 0-6.3 mm (TSE), and 0-11.3 mm (GE).
• Lower field strength (0.2 T) generally produced smaller artifacts across all tested sequences.

Conclusions:

• Lower magnetic field strength (0.2 T) is superior for passive visualization of the tested MR-compatible needles.
• Gradient echo (GE) imaging, particularly at lower field strengths, offers improved needle visualization.
• The findings guide the selection of optimal MR parameters for procedures requiring passive needle visualization.