Doppler evaluation of the posterior cerebral artery in fetuses with transposition of great arteries.

Objective: To observe Doppler ultrasound changes in the two segments of the posterior cerebral artery (PCA) in fetuses with transposition of the great arteries (TGA). Methods: The peak systolic velocity (PSV), end-diastolic velocity (EDV), pulsatility index (PI), and velocitytime integral (VTI) of the two segments of PCA (the first segment: PCAS1, the second segment: PCAS2) and of the middle cerebral artery (MCA) were compared in TGA fetuses and normal fetuses. The abnormality rate between the PCAS1-PI and MCA-PI was compared in TGA fetuses. Results: The PCAS1-PI and MCA-PI were smaller in the TGA fetuses than in the controls (all P <0.05), but the PCAS2-PI was unchanged (P> 0.05). The MCA-VTI, PCAS1-VTI, and PCAS2-VTI were larger in the TGA fetuses (all P < 0.05). In the TGA fetuses, the abnormality rate of the PCAS1-PI was significantly higher than that of the MCA-PI (P < 0.05). Conclusion: In fetuses with TGA, there were hemodynamic differences between the two segments of the posterior cerebral arteries. Moreover, PCAS1 exhibited signs of vasodilatation more obviously than did the MCA in fetuses with TGA.