Neonatal diffusion-weighted MR imaging: Relation with histopathology or follow-up MR examination

Purpose: Diffusion-weighted imaging (DWI) has become a standard method for early evaluation of stroke in adults, but its value in neonates is less well established. In this study neonatal DWI was compared with histopathology in those patients who died, or with sequelae seen on a second MR in the surviving neonates. Patients and Methods: DWI was performed in 2 groups. Group 1: seven neonates who died and had a post-mortem examination (perinatal asphyxia [n = 5], symptomatic hypoglycemia [n = 1], periventricular leukomalacia [n = 1]). Group 2: six surviving neonates with a second MR examination at three months of age (perinatal asphyxia [n = 2], neonatal stroke [n = 3], meningo-encephalitis [n = 1]). Results: In group I neonatal DWI showed more extensive involvement than conventional MRI in 6 out of 7 patients. These changes were less extensive, however, than seen post-mortem by histopathology in 5 out of 7. In group 2 neonatal DWI showed more extensive involvement than conventional MRI in 2 out of 6: 4 out of 6, however, showed less extensive cystic evolution on follow-up MRI at 3 months than expected from neonatal imaging. Conclusion: There was a good relation between hyperintense areas on DWI and areas of cytotoxic edema and neuronal damage on histopathology. In the survivors a second MRI showed cystic evolution in all, but the volume of the cysts was smaller than expected on the basis of the neonatal DWI findings.