PRENATAL-DIAGNOSIS OF TETRALOGY OF FALLOT BY DOPPLER COLOR-FLOW MAPPING

The prenatal diagnosis of tetralogy of Fallot (TOF) can be difficult, as the routine sonographic four-chamber view may be normal before birt h. Unlike the normal fetus, in which blood flows adjacent to the left side of the interventricular septum, on color Doppler mapping a fetus with TOF also demonstrates antegrade flow along the right side of the interventricular septum. This Y-shaped ventricular outflow passing thr ough the dilated aortic tract is confluent at the level of the ventric ular septal defect during the systolic phase. In the past 3 years, thr ee cases of TOF have been diagnosed prenatally at the Chang Gung Memor ial Hospital. In each case, the above picture was demonstrated. 2-Dime nsional Doppler color flow mapping may be helpful in the prenatal diag nosis of TOF.