Magnetic resonance and cranial ultrasound characteristics of periventricular white matter abnormalities in newborn infants

OBJECTIVE: To characterize the range of abnormalities within the periventri cular white matter (PVWM) in a cohort of newborns using magnetic resonance (MR) brain imaging and to compare the focal MR abnormalities with the crani al ultrasound (CUS) findings. METHODS: Retrospective study of MR brain and CUS findings of infants born i n the 18-month period 1998-1999. PVWM abnormalities were identified by MR a nd focal lesions were characterized by size, number and distribution using a grading scale. Correspondence with CUS findings was assessed. RESULTS: 175 MR examinations corresponding to n = 105 preterm infants, (med ian GA 28, range 23-36 weeks) and n = 25 term infants (median GA 39, range 37-42 weeks) were analysed for PVWM abnormalities. In the preterm group, MR demonstrated a normal PVWM in n = 76, focal areas of altered signal intens ity (ST) in PVWM in n = 26 and venous infarction in n = 3. In the term grou p, MR demonstrated a normal PVWM in n = 15, focal areas of altered SI in PV WM in n = 4, oedematous PVWM in it = 2 and a middle cerebral artery infarct ion in n = 4. All infants with normal MR had normal CUS findings. A focal P VWM SI abnormality detectable on MR corresponded with an abnormality on CUS in only n = 10/30. CONCLUSIONS: MR appears considerably more sensitive than CUS in demonstrati ng the existence and extent of focal PVWM lesions in newborn infants. Satis factory correspondence between the two imaging investigations is obtained o nly for cystic PVWM lesions. (C) 2001 The Royal College of Radiologists.