Neuroimaging in Preterm Infants: Comparison between Magnetic Resonance Imaging and Ultrasonography

ABSTRACT

PURPOSE: Brain magnetic resonance imaging (MRI) scans have become increasingly popular as a predictive tool for neurodevelopmental outcome in preterm infants, while serial brain ultrasonograms remain as a standard evaluation modality for neonatal brain. The aim of this study was to determine whether brain MRI taken at term-equivalent age could give us further information over serial brain ultrasonograms taken during admission. METHODS: We analyzed 225 preterm infant (<32 weeks gestational age) who were admitted to NICU at Seoul National University Bundang Hospital from January 2006 to June 2011. The 28 infants with chromosomal abnormalities or major congenital anomalies were excluded. We compared abnormal findings between brain MRI scan taken at term-equivalent age and serial brain ultrasonograms taken during admission in 197 preterm infants. RESULTS: The brain MRI scans taken at term-equivalent age showed normal findings in 142 out of 197 (72%) infants and abnormal findings in 55 out of 197 (28%) infants. The brain ultrasonograms during admission revealed 82 intraventricular hemorrhages, 90 periventricular leukomalacias, 7 brain parenchymal lesions, 3 ischemic lesions. Brain MRI scans discovered 30 intraventricular hemorrhages, 10 periventricular leukomalacias, 12 brain parenchymal lesions, 3 ischemic lesions. Ventriculomegaly was discovered only by the brain ultrasonography. Five brain parenchymal lesions and 9 cerebellar lesions were appeared only on the brain MRI scans. Brain MRI scans taken at term-equivalent age detected grade 1 or 2 intraventricular hemorrhages which were not discovered by last brain ultrasonograms. CONCLUSION: In compare to the serial brain ultrasonograms, the brain MRI scan taken at term-equivalent age is advantageous in discovering brain parenchymal lesions and cerebellar lesions and precise grading of intraventricular hemorrhage in preterm infants.