Question

During cardiac imaging the phase of minimum motion of the heart is:

• A. Late systole
• B. Mid systole
• C. Late diastole
• D. Mid diastole

Hint:

The diastasis period of slow filling in mid diastole is the quietest moment.

Answer 1

The Correct Option is D

Step 1: In cardiac imaging such as CT coronary angiography, motion blur is least when the heart is most still. The goal is to time image capture to the quietest part of the cardiac cycle.
Step 2: The heart has two relatively still windows: end systole, and mid diastole during the phase called diastasis. Diastasis is the slow filling period that sits between the early rapid filling of the ventricle and the late atrial contraction.
Step 3: At normal and slow heart rates the longest and most reliable rest period is mid diastole (diastasis), so this is the phase used for the best images of the coronary arteries.
Step 4: Comparing the options, late systole and mid systole still involve vigorous wall motion, and late diastole includes the atrial kick which moves the heart again. Mid diastole, the diastasis phase, has the least motion.
Conclusion: The phase of minimum cardiac motion is mid diastole. Answer is option D.