Assessment of ventricular synchrony by positron emission tomography: With great power comes great responsibility

Excerpt

Phase analysis of gated radionuclide myocardial perfusion imaging is an established technique for the assessment of left ventricular synchrony (LVS), and is based on determination of the dispersion in the timing of myocardial contraction of individual segments during a cardiac cycle. Central to the assessment of LVS by phase analysis is the relatively linear relationship between myocardial thickening and myocardial count density in all myocardial segments (i.e., brighter myocardium in systole).1 Thus, the time-activity curve of a myocardial segment is essentially its temporal thickening curve, which is enhanced by the application of Fourier transformation of the time-activity data to generate a continuous thickening curve that delineates the timing of segmental myocardial contraction.2,3 This thickening curve is generated for over 600 myocardial voxels during a standard myocardial perfusion acquisition. With this approach, the initiation of contraction can be determined, compared among segments and can be represented as a phase distribution (histogram). …