Rapid quantitative assessment of myocardial perfusion: Spectral analysis of myocardial contrast echocardiographic images

Abstract

We described a novel rapid spectral analysis technique performed on raw digital in-phase quadrature (IQ) data that quantitatively differentiated perfused from nonperfused myocardium based on the simultaneous comparison of local fundamental and harmonic frequency band intensity levels. In open-chest pigs after ligation of the left anterior descending coronary artery (LAD) and continuous venous contrast infusion, the fundamental-to-harmonic intensity ratio (FHIR) for samples placed within the left ventricular (LV) cavity (10.8 ± 1.7 dB) and perfused myocardium (13.7 ± 1.6 dB) were significantly (P <.001) lower than for nonperfused myocardium (27.1 ± 2.9 dB). In attenuated images, the FHIR for the LV cavity and perfused myocardium were also significantly (P <.05) lower than for the nonperfused myocardium (21.4 ± 3.0 dB, 34.4 ± 3.2 dB, and 40.2 ± 4.4 dB, respectively). Spectral properties of contrast microbubbles, as characterized by the FHIR, allow for rapid quantitative assessment of myocardial perfusion from data contained in a single-image frame, without requiring background image subtraction and image averaging. (J Am Soc Echocardiog 2002;15:63-8.)