What situation poses the greatest risk to a patient with a coiled wire?

The situation that poses the greatest risk to a patient with a coiled wire is represented by a coil with many small loops in the axial plane. When assessing the risks associated with different coil configurations in a magnetic resonance imaging (MRI) environment, it is important to consider the potential for induced currents and the resultant heating effects from the interaction between the magnetic field and the wire.

Coils with many small loops have a higher surface area and greater electrical induction capability due to their geometric configuration. In the presence of a strong magnetic field, small loops can lead to more significant circulating currents. This is particularly important in the axial plane, where the orientation of the wire interacts directly with the magnetic field's gradients, increasing the likelihood of unwanted phenomena such as heating and movement of the coil, which can pose serious risks to patient safety.

In contrast, coils designed as large loops, whether in axial or coronal planes, typically do not create the same level of problematic induced currents due to their larger circumference and lower density of electrical loops. Thus, while they still present some risk, they are not as concerning as coils with many small loops.

Fundamentally, understanding the physical properties of different coil configurations and how they interact with the magnetic fields in an MRI system is crucial