Apparent normal arrangement pattern of three-vessel view in a fetus with transposition of great arteries and L-malposed aorta.

Transposition of great arteries (TGA) is more commonly associated with D-malposition of great arteries where anterior aorta produces characteristic "I" sign in the three-vessel view (3VV) in fetal heart imaging. We describe two cases with TGA and L-malposition of aorta where 3VV imaging showed an apparently normal arrangement of vessels while outflow tract imaging proved vital in diagnosing transposition anatomy. Apparently, normal 3VV in the presence of disproportionate vessel caliber and inability to produce normal outflow images should raise the suspicion. Attempts should be made to produce views to show great arteries originating from respective ventricles to rule out ventriculoarterial discordance and to complete segmental analysis.