Feasibility and accuracy of left ventricular volumes and ejection fractiondetermination by fundamental, tissue harmonic, and intravenous contrast imaging in difficult-to-image patients

The need to enhance the echocardiographic determination of left ventricular ejection fraction is greatest in patients with suboptimal images. Intraven ous contrast (CON) and tissue harmonic imaging (THI) are 2 important method s for enhancing endocardial border definition. However, the comparative fea sibility and accuracy of THI and contrast-enhanced power harmonic imaging i n difficult-to-image patients have not been examined. We assessed the compa rative accuracy of THI and CON in determining EF and ventricular volumes in patients with suboptimal fundamental images. We demonstrated that CON is f easible and exhibits a greater correlation with ejection fraction and ventr icular volumes determined by radionuclide angiography (standard of comparis on) than THI in this difficult-to-image population, with no reported side e ffects. For both ejection fraction and ventricular volumes, the observer va riability was least for CON, intermediate with THI, and greatest for fundam ental imaging.