Radionuclide angiocardiography in the diagnosis of congenitally corrected transposition of the great arteries.

Congenitally corrected transposition of the great arteries (CTGA) may constitute a pitfall for interpretation of radionuclide angiocardiography, since the two anatomic discordances cancel each other from a physiologic point of view. However, the unusual shape of the ventricles (due to ventricular discordance) and the relative position of the great arteries (due to transposition) can allow a clear scintigraphic diagnosis, especially for CTGA with mild or absent associated congenital anomalies. Five cases are described. Gated cardiac blood pool imaging is particularly helpful since it permits multiple views, allowing a more detailed study of the scintigraphic signs.