Adult congenital heart disease: use of transthoracic echocardiography versus magnetic resonance imaging scanning.

There are many potential imaging modalities available for the assessment of patients with adult congenital heart disease, yet a dearth of information exists as to their comparative clinical value. Transthoracic echocardiography provides high-resolution, real-time imaging of intracardiac structures and is well suited to the investigation of these patients. It is limited by problems of acoustic penetration that vary from patient to patient, and rarely provides high-quality images of the great vessels in adults. The introduction of spectral Doppler ultrasound and color Doppler flow mapping has greatly enhanced the accuracy and quantitative ability of cardiac ultrasound in adult congenital heart disease. Magnetic resonance imaging is not subject to the problems of ultrasound but does not provide real-time imaging and it is comparatively expensive and time consuming. However, the high-resolution imaging it provides is a major advance in the investigation of patients with poor transthoracic echocardiograms or in delineating the extracardiac structures often unseen by conventional echocardiography. Transthoracic echocardiography and magnetic resonance imaging are complimentary investigations in adult congenital heart disease providing high-resolution anatomic and functional information in even the most complex forms of congenital heart lesions in this difficult and expanding population.