Marina Vakaki, Presenter: Nothing to Disclose

Efthymia Alexopoulou, Abstract Co-Author: Nothing to Disclose

Chris Koumanidou, Abstract Co-Author: Nothing to Disclose

Several studies have suggested that periventricular hemorrhage is actually hemorrhagic venous infarction resulting from terminal vein obstruction by an adjacent germinal matrix hemorrhage. For the detailed evaluation of intracranial hemorrhage in preterm neonates and  for prognostic reasons, a thorough understanding of the anatomical position and normal flow profiles and velocities in terminal veins is essential. Purpose: To establish the effectiveness of color Doppler US in identifying the terminal veins of preterm neonates, in both cerebral hemispheres  To evaluate normal blood flow velocities by pulsed Doppler US measurements.  

50 clinically stable preterm neonates (gestational age 24-36 weeks, post natal age less than 1 week) were sonographically studied in the intensive care unit. A routine gray-scale US to exclude intracranial disease was followed by Doppler US. Terminal veins were illustrated by color Doppler. Maximal and mean flow velocities were measured by Pulsed Doppler.

In coronal planes, the terminal veins (n=98) were easily depicted lateral and inferior to the lateral ventricle floor, close to germinal matrix in 49 neonates. In one 26-gestational week newborn they could not be visualized. The right terminal vein not demonstrated in the first US of a 28-w neonate, was depicted in the second US 3 days later. Terminal veins were characterized by continuous, low-velocity flow. A linear correlation between gestational age and flow velocity in the terminal vein was seen. Maximal blood flow velocity increased from 1.52 cm/sec at 24 gestational weeks to 5.09 cm/sec at 36 weeks. Mean flow velocity ranged from 0.66 cm/sec to 3.40 cm/sec respectively. No difference could be seen between cerebral hemispheres.

Color Doppler visualization of the terminal veins is possible in almost all preterm neonates (98%). Maximal and mean flow velocity increases from 24 to 36 gestational weeks. Color and pulsed Doppler of terminal veins is helpful in US monitoring of preterm neonates at high risk for germinal matrix/intraventricular haemorrhage and periventricular hemorrhagic infarction. To the best of our knowledge, this is the largest prospective US study of normal terminal veins in preterm neonates, including extremely premature neonates also.

Color and pulsed Doppler examination of the normal terminal veins is effective in premature neonates and seems promising.

Vakaki, M, Alexopoulou, E, Koumanidou, C, Terminal Veins in Premature Neonates: Normal Findings in Color and Pulsed Doppler Sonography.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6013905.html