For a patient with a heart rate of 90 beats/min and a trigger window of 15%, what is the available imaging time if the trigger delay is 80ms?

To determine the available imaging time in the context of cardiac MRI with a heart rate of 90 beats per minute and a trigger delay of 80 ms, we first need to convert the heart rate into a cardiac cycle duration.

A heart rate of 90 beats per minute means each cardiac cycle lasts approximately 60000 ms / 90 beats = 666.67 ms. This is the total time from one heartbeat to the next.

The trigger window is set to 15% of the cardiac cycle duration, which means that the imaging must occur during 15% of that cycle. To calculate the length of the trigger window, we can multiply the total cycle time by 0.15:

0.15 × 666.67 ms = 100 ms

With a trigger delay of 80 ms, the available time for imaging is the total cycle time minus the trigger delay minus the duration of the trigger window:

Available imaging time = Total cycle time - Trigger delay - Trigger window

Available imaging time = 666.67 ms - 80 ms - 100 ms

Available imaging time ≈ 486.67 ms

When rounded to the nearest whole number, the result is approximately 487 ms. This corresponds to the correct