Is power motion imaging superior to standard 2 dimensional echocardiography for myocardial visualization?

Though routine 2D echo imaging (2D) is rapid and low-cost, technically difficult, poor quality images can limit its diagnostic yield. Amplitude-based Doppler myocardial tissue imaging (Power Motion™ Imaging, PMI, ATL, Bothell, WA) provides a real-time, Doppler based presentation of wall motion using the amplitude components of the Doppler spectrum which can be activated by a single key stroke during a routine exam. To determine whether PMI provides superior myocardial recognition compared to 2D, we imaged 103 patients in whom the endocardial definition in at least 2 of 6 LV wall segments in either the apical 2 or 4 chamber views could not be adequately visualized. Patients were imaged initially with 2D, then immediately thereafter with PMI at the same machine settings (P3-2MHz scanhead, HDI® 3000cv, ATL, Bothell, WA). The 206 image sets (2/pt) were separated and randomized on SVHS tape and read independently by 3 investigators who categorized the 12 ventricular wall segments as either "well-visualized", "poorly visualized" or "non-visualized". PMI Nonvisualized PMI Poorly Seen PMI Well Seen 20 Non-visualized 437 600 357 20 Poorly seen 132 677 339 20 Well-seen 38 226 716 Of 1394 segments not seen by 2D, 957 (69%) were visualized by PMI; of 1148 poorly seen LV segments by 2D, 30% were well-visualized by PMI; and of 980 LV segments seen well by 2D, only 3.9% were non -visualized by PMI. These results were highly statistically significant (p=.001). The clinical impact of PMI was greatest in the anterior, septal and lateral walls. Thus, Power Motion Imaging may increase the yield of interpretable exams in patients with poor quality studies.