If a patient has a heart rate of 70 beats per minute, what is the effective TR?

To determine the effective repetition time (TR) based on the heart rate, it is important to understand the relationship between heart rate and TR in the context of cardiac MRI.

The effective TR can be calculated using the formula:

[ \text{Effective TR} = \frac{60,000 \text{ ms/min}}{\text{Heart Rate (beats/min)}} ]

In this case, with a heart rate of 70 beats per minute, the calculation would proceed as follows:

1. Convert the heart rate into the time per beat. This can be done by taking 60,000 ms (which is the number of milliseconds in a minute) and dividing it by the heart rate:

[ \text{Effective TR} = \frac{60,000}{70} \approx 857 \text{ ms} ]

This calculation aligns with the effective TR provided in the answer choice, confirming that the effective TR at a heart rate of 70 beats per minute is approximately 857 ms. This also illustrates how slower heart rates correspond to longer TR times, as the heart takes longer to complete one full cycle.

In cardiac MRI, knowing the effective TR helps optimize imaging sequences to capture comprehensive cardiac motion while minimizing artifacts related