Which factor does not contribute to an increase in Specific Absorption Rate (SAR) during a pulse sequence?

The correct answer is based on understanding how the Specific Absorption Rate (SAR) is influenced by various factors during an MRI pulse sequence. SAR is a measure of the rate at which energy is absorbed by the body when exposed to the radiofrequency (RF) fields of the MRI system.

Receiver bandwidth plays a role in the amount of RF energy emitted during the pulse sequence, but it does not inherently contribute to an increase in SAR. Receiver bandwidth primarily impacts the frequency range of the signals being captured rather than the energy absorption rate itself. A wider bandwidth can decrease SAR since it requires less RF energy for adequate signal reception, as it allows for a more efficient use of the available frequency range.

In contrast, factors like pulse sequence duration, flip angle, and magnetic field strength are directly related to the energy deposited in the body. The longer the pulse sequence duration, the more RF energy is delivered, leading to a higher SAR. The flip angle determines the amount of RF energy used to excite the protons; larger flip angles typically result in a higher SAR due to increased energy absorption. Likewise, higher magnetic field strengths often require more RF energy to achieve the desired excitation levels, which also elevates SAR.

Thus, understanding these dynamics clarifies why receiver