CINE GRADIENT-ECHO MR-IMAGING AND MR VELOCITY MAPPING IN THE EVALUATION OF CONGENITAL HEART-DISEASE

Cine gradient-echo (GRE) magnetic resonance (MR) imaging and MR veloci ty mapping can be applied to assess cardiovascular function and to mea sure volumetric flow in patients with repaired and untreated congenita l heart disease, GRE images, particularly when displayed in a cine loo p, are very useful for visualizing surgical anastomoses and conduits a nd for detecting stenosis, regurgitation, and left-to-right shunts. Mu lti-section cine GRE imaging is a suitable method for measuring global right ventricular function, an important issue in congenital heart di sease, MR velocity mapping is used for quantitative assessment of hemo dynamics. Pressure gradients can be estimated from peak blood flow vel ocities in stenotic pulmonary arteries or surgical conduits, Because f low volume can be measured with MR velocity mapping, main-, left-, and right pulmonary artery flow, valvular regurgitation, left-to-right sh unts, and ventricular filling call all be quantified. The abilities to elucidate complex cardiac anatomy and to measure cardiac function and flow in one examination make MR imaging a useful comprehensive tool f or follow-up of congenital heart disease.