Presented at the Neonatal Society 2014 Spring Meeting.
Darekar A, Thyagarajan B1, Joy H, Gawne-Cain M, Baral V, Kirkham F, Vollmer B
University Hospital Southampton and Faculty of Medicine, University of Southampton, Southampton, UK
Background: Susceptibility-weighted imaging (SWI) is a relatively new MR imaging technique which highlights blood, blood products, iron, and calcification. It is increasingly used in paediatric neuroimaging; however, currently, there is little information available on SWI in neonatal imaging. The aims of this pilot study are to explore the use of SWI in newborns with HIE. We aimed to investigate whether SWI may be a useful adjunct to conventional MRI. We explored associations between SWI and neurological outcome to determine whether SWI is a useful addition to standard MRI in predicting outcome.
Methods: Fifty-one term born newborns with HIE who underwent hypothermia treatment were scanned on a 1.5T Siemens Symphony MRI scanner (mean age at MRI 7.6, SD 5.6 days). The protocol included proton density (PD), T1-weighted, T2-weighted, turbo inversion recovery (IR) and SWI. Two paediatric neuroradiologists scored the T1-weighted and T2-weighted MRIs using the “Barkovich” scoring system1, which assesses the basal ganglia (BG) and watershed (WS) regions. A locally developed “prominence of veins” score, based on Kitamura et al,2, was used for assessment of the SWI images. Scores were related to neurological outcome at age 12 months. Ethics approval was granted by NRES Committee London – City & East (13/LO/1948).
Results: Good quality MRI data were available for 38/51 (28 boys, 23 girls; mean BW 3376, SD 594.8 g) newborns, and neurological outcome data were available for 26/38 newborns (14 boys, 12 girls). Eleven out of the 26 newborns had supplementary oxygen during MRI. Both the combined highest watershed and basal ganglia score derived from the T1-w and T2-w images (partial correlation coefficient 0.486; p=0.035) and the total SWI score (partial correlation coefficient -0.493; p=0.032) were related to neuromotor status at age 12 months (controlling for age at scanning).
Conclusion: This study has provided valuable pilot SWI data in a homogeneous cohort of newborns. SWI appears to be a useful adjunct to standard imaging in HIE, and there is the potential that SWI could help predict neurological outcome. However, further work is required to fully assess the value of SWI. For example, the potential effects of variations in blood oxygenation and blood flow on SWI signal intensity, which might be present in newborns with HIE, have to be investigated further.
Corresponding author: b.vollmer@soton.ac.uk
References
1. Barkovich AJ, et al. AJNR Am J Neuroradiol. 1998 Jan;19(1):143-9.
2. Kitamura G, et al. Pediatr Neurol. 2011 Oct;45(4):220-4.