Which of the following functional images represents the magnitude of ventricular contraction?

The correct answer focuses on the non-phase image, which is instrumental in representing the magnitude of ventricular contraction. Non-phase images are typically obtained in nuclear medicine using techniques like single-photon emission computed tomography (SPECT) or positron emission tomography (PET). These images reflect overall myocardial perfusion and function rather than the timing or synchronization of contraction phases.

In evaluating ventricular contraction, the non-phase image effectively illustrates the extent to which the heart contracts and thus can highlight any areas of reduced wall motion or perfusion that may indicate underlying cardiac issues. By capturing data during the contraction phase without emphasizing the timing of the phases, it provides clear insight into the performance of the ventricles in relation to blood ejection.

Other options, such as the phase image and amplitude image, would focus more on different aspects of the cardiac cycle, like timing of contractions or the strength of contractions in certain contexts, rather than providing a direct measure of the magnitude of contraction. These images are useful in other settings but do not primarily represent the overall effectiveness of ventricular contraction the way a non-phase image does.