Diffusion Tensor Imaging in Very Preterm, Moderate-Late Preterm and Term-Born Neonates: A Systematic Review.

OBJECTIVE: To examine white matter abnormalities, measured by diffusion tensor imaging, in very preterm (<32 weeks) and moderate-late preterm neonates (32-37 weeks) at term-equivalent age, compared with healthy full-term controls (≥37 weeks). STUDY DESIGN: A search of Medline (PubMed) was conducted to identify studies with diffusion data collected on very preterm, moderate-late preterm and full-term neonates, using the guidelines from the Meta-analysis of Observational Studies in Epidemiology and PRISMA statements. RESULTS: Eleven studies were included with diffusion tensor imaging data from 554 very preterm, 575 moderate-late preterm, and 318 full-term neonates. Widespread statistically significant diffusion measures were found in all preterm subgroups at term-equivalent age compared with full-term neonates, and this difference was more marked for the very preterm group. These abnormalities are suggestive of changes in the white matter microstructure in the preterm groups. The corpus callosum was a region of interest in both early and moderate-late preterm groups, which showed statistically significant diffusion measures in all 11 studies. CONCLUSIONS: Microstructural white matter changes may underpin the increased risk of neurodevelopmental disability seen in preterm infants in later life. diffusion tensor imaging may therefore be a useful prognostic tool for neuro-disability in preterm neonates.

Influence of a patent ductus arteriosus on cardiac troponin T levels in preterm infants.

OBJECTIVE: To evaluate the effect of patent ductus arteriosus (PDA) on the myocardium by measuring levels of cardiac troponin T (cTnT), a marker of ischemic myocardial damage. STUDY DESIGN: Eighty infants with a median gestation of 28 weeks (interquartile range ([IQR] = 26.1 to 29.5 weeks) and median birth weight of 1.06 kg (IQR = 0.87 to 1.21 kg) underwent echocardiographic and cTnT assessments at 12 and 48 hours of life. The infants with PDA were treated with ibuprofen or surgical ligation. Follow-up echocardiography and cTnT assay was performed after treatment. RESULTS: The median 12-hour cTnT level was 0.20 microg/L (IQR = 0.11 to 0.40 microg/L). At 48 hours, median cTnT level was significantly higher in the PDA group (n = 45) than in the spontaneous closure group (n = 35) (0.43 vs 0.13 microg/L; P < .001). Following successful treatment, cTnT levels decreased significantly, to 0.10 microg/L (P < .001). cTnT levels correlated significantly with ductal diameter, left atrial-to-aortic diameter ratio, and descending aortic end-diastolic velocity. The receiver operating characteristics curve for detection of PDA through cTnT values had an area under the curve of 0.78 (95% confidence interval = 0.66 to 0.90; P < .001). CONCLUSIONS: cTnT may be a useful marker of ductal significance and treatment response, because it correlates with echocardiographic markers of PDA. Elevated cTnT level may reflect the potential myocardial damage caused by a PDA.