Assessment of the Main Fetal Cerebrovascular Areas by Ultrasound Color‐Coded Doppler

The color flow mapping method makes it possible to identify small vessels presently not detected on B‐mode imaging. The main cerebral arteries of normal human fetuses, anterior, middle, and posterior arteries, were investigated by color‐coded Doppler in 45 normal pregnancies. The Pourcelot index R was calculated at different stages of the pregnancy. The values of R (anterior cerebral artery), R (middle cerebral artery), and R (posterior cerebral artery) were compared in each fetus. No significant differences were found when comparing all of the R (anterior cerebral artery) and R (middle cerebral artery) or the R (anterior cerebral artery) and R (middle cerebral artery) at the same gestational age. On the contrary, for each fetus, at any gestational age, the R (anterior cerebral artery) and the R (middle cerebral artery) indices were significantly different (P < 0.01); the index in the middle cerebral artery was higher than that of the anterior cerebral artery. The same difference was observed when comparing R (posterior cerebral artery) and R (middle cerebral artery). The index of the middle cerebral artery was significantly higher than that of the posterior cerebral artery (P < 0.001). On the other hand, no significant difference was found between R (anterior cerebral artery) and R (posterior cerebral artery) at any gestational age (P = 0.4).