Clinical application of quantitative analysis in real-time MCE

Abstract

The introduction of stable microbubble contrast agents and technological advances have recently made it feasible to perform quantitative measurements of microvascular damage by myocardial contrast echocardiography (MCE). Qontrast ® is a new software system for such measurements. It includes physiological filters, global rescale, regional rescale, automatic myocardial tracking, manual ECG trigger and parametric imaging.

Qontrast ® was tested on 5 pigs given sulphur hexafluoride bubbles (1 ml/min) and fluorescent microspheres (reference) after the induction of 50% and 100% stenosis of left anterior descending coronary artery. The image sequences were repeated four times using different ultrasound (US) equipment. A close correlation was found between the ratio risk area/control area by microspheres and the equivalent ratio risk area/control area (Sl× β ) by MCE, being approximately 0.9 for any contrast modality tested.

Parametric MCE and SPECT compared in 12 patients with recent myocardial infarction, including 119 segments. Agreement amounted to 83% (kappa: 0.53 for peak SI and 0.55 for SI xβ). The sensitivity and specificity of peak SI for detecting abnormal segmental tracer uptake were 67% and 88%; the values for Sl× β were 70% and 87%.

Parametric MCE is a promising imaging technique for the assessment of myocardial perfusion in patients with suspected or known coronary artery disease.

Myocardial contrast echocardiography, Myocardial perfusion, Microcirculation