The value of radiographic screening for metallic particles in the equine foot and size of related artifacts on low-field MRI.

This research article primarily investigates the effectiveness of radiographs in detecting metallic particles in horse feet as well as estimating the resultant size of the artifact in MRI scans.

Overview of the Research

• The study primarily focuses on the issue of magnetic susceptibility artifacts that often result from metal debris in MRI scans of horse feet – a side effect of the shoeing process.
• The research sought to examine how applicable radiography could be as a tool for screening for the presence and positioning of these metal particles in horse feet and estimating the size of the related artifacts in MRI scans.

Methods and Findings

• Radiographs were used to detect metal particles of at least 1mm diameter, with a 100% sensitivity rate.
• A selection of metal particles of known diameter were deposited in the hoof wall of 22 horse cadaver feet, which were then scanned using a low-strength MR imaging unit.
• The MRI scans were marked by a signal void, a hyperintense rim, and an image distortion at the specific location of the metal.
• Different sequences revealed varying degrees of artifacting. T2* weighted sequences showed the most artifacting and fast spin echo (FSE) sequences showed the least.
• All four sequences examined were found to have a linear relationship between particle size and resultant artifact size. These sequences include T1 gradient echo (GRE), T2*W GRE, T2 FSE, and short tau inversion recovery FSE.

Conclusion and Recommendations

• The researchers concluded that the size, location, and overlap on clinically relevant anatomical structures of magnetic susceptibility artifacts can be predicted using radiographic imaging for metal particles larger than 1mm.
• If it is impossible to remove metal debris, the authors suggested opting for FSE sequences in MRI scans as those were found to be the least affected by artifacts.