Abnormal venous drainage in periventricular leukomalacia.

Age-matched six control subjects and 14 selected paediatric patients with periventricular leukomalacia were prospectively studied by MR imaging, and MR angiography. MR angiograms were acquired utilizing either the three-dimensional phase-contrast (3D-PC) or the two-dimensional time-of-flight (2D-TOF) techniques, or both, in an axial slab centred to the centrum semiovale. Abnormal draining veins (slightly enlarged and long vessels with abnormal courses) were found in eight of 14 patients (57%). In five of these eight patients (62.5%) abnormal vessels were identified on conventional MR imaging (spin-echo, T2-weighted and flow sensitive images), while the 3D-PC or 2D-TOF angiograms demonstrated the abnormal vessels in all the patients (100%). Usually there was single abnormal vessel at the region of interest. These vessels should not be misinterpreted as arteriovenous malformations or venous malformations.