Color Doppler US is useful for assessing bowel viability in patients with suspected or proved necrotizing enterocolitis . Bowel perfusion in normal neonates, as demonstrated at color Doppler US by using a velocity setting of 8.6 cm/sec, ranged from one to nine color dots per square centimeter . To our knowledge, no studies have been published about Doppler spectra in the setting of normal bowel vascularity. However, in our experience, both arterial (Fig a) and venous (Fig b) spectra may be obtained in the bowel wall.

a-

b-

Arterial (a) and venous (b) spectral waveforms obtained in the bowel wall of an 18-day-old girl show normal perfusion.