In a 3T scanner, a stent of what length is at the highest risk for resonant heating?

In the context of magnetic resonance imaging (MRI), resonant heating can occur due to the interaction of radiofrequency (RF) fields with conductive materials, such as stents. Stents that are longer and have a significant amount of conductive material present a higher risk of resonant heating because they can more effectively absorb and concentrate the RF energy.

A stent that is 13 cm long is considered to be at higher risk for resonant heating than longer or shorter lengths. This is due to the fact that within the magnet's RF field, certain lengths can resonate at particular frequencies, causing them to heat up. A 13 cm stent could fall within a problematic range that aligns closely with the RF wavelength, leading to a greater likelihood of experiencing increased temperatures.

In contrast, a stent that is shorter, like 5 cm, is less likely to resonate with the RF fields, and hence less at risk for significant heating. A 25 cm stent may still resonate, but its longer length could shift it away from the critical resonance frequency depending on the RF field configuration. The 40 cm stent, while it may also have concerns for heating, generally would not represent the highest risk like the 13 cm, as various lengths can fluctuate