Which term describes the combination of two factors in determining gradient efficiency?

The term that describes the combination of two factors in determining gradient efficiency is slew rate. Slew rate refers to the rate at which the gradient magnetic field can change over time, typically expressed in units such as tesla per meter per second (T/m/s). It is a crucial parameter because it directly influences how quickly gradients can be turned on and off.

In magnetic resonance imaging (MRI), the slew rate affects the time it takes for the gradients to reach their full strength, which in turn determines how quickly the MRI system can acquire images. A higher slew rate allows for faster imaging and can improve temporal resolution, which is essential for capturing dynamic processes.

While gradient strength and field duration are also important factors in MRI, they do not encompass the idea of efficiency in the context of how quickly gradients can ramp up and down, or how effectively imaging can be performed in a given time frame. Magnetic field intensity primarily relates to the strength of the main magnetic field and does not directly address gradient efficiency. Therefore, slew rate correctly captures the essential combination of factors that determine the efficiency of gradient operations.