Which of the following is NOT a recognized risk from gradient magnetic fields?

In the context of MRI and the effects of gradient magnetic fields, it is essential to understand the various physiological responses to these fields. Cardiac arrhythmias, peripheral nerve stimulation, and tissue heating are all potential risks associated with exposure to gradient magnetic fields during an MRI scan.

Cardiac arrhythmias can occur due to the interaction of rapidly changing gradients with the electrical activity of the heart, particularly in sensitive individuals. Peripheral nerve stimulation happens when gradient fields induce currents in the body's conductive tissues, leading to sensations such as tingling or discomfort. Tissue heating is a well-documented risk, as the interaction of the magnetic field with bodily tissues can cause localized heating.

In contrast, increased body fat is not a recognized risk from exposure to gradient magnetic fields during MRI. The mechanisms associated with gradient fields do not lead to changes in body fat composition, since body fat is influenced by metabolic processes and factors unrelated to the MRI technology itself. Therefore, while the other options represent legitimate risks during MRI procedures, the potential for increased body fat is not linked to gradient magnetic field exposure.