Which SAR limit might be exceeded when using improper padding techniques?

The correct answer is associated with the Specific Absorption Rate (SAR) limits established for different body areas during magnetic resonance imaging (MRI) procedures. The SAR is a measure of the amount of radiofrequency power absorbed per unit mass of tissue, and it is crucial for ensuring patient safety during MRI scans.

Option C, which indicates a SAR limit of 3.2 W/kg for the head, is particularly relevant when discussing the potential risks associated with improper padding techniques. When padding is used incorrectly, it can lead to insufficient or uneven distribution of RF energy across the patient's body, resulting in certain areas, especially the head, absorbing more energy than intended. This can potentially exceed the designated SAR limits, particularly for the head, which is more sensitive and has a lower thermal tolerance compared to other body parts.

Understanding the significance of these limits is essential, as exceeding them can lead to adverse thermal effects or tissue damage. Proper padding techniques are crucial in maintaining compliance with SAR limits and ensuring patient safety during MRI procedures. Therefore, attention to detail in the padding process is necessary to minimize the risk of exceeding the SAR allowance for sensitive areas like the head, which is why the 3.2 W/kg limit is particularly relevant here.