Diagnostic accuracy of cranial sonography in detection of hypoxic ischemic encephalopathy in clinically suspected premature infants keeping MRI as gold standard

Abstract

Background: Neonatal hypoxic ischemic encephalopathy (HIE) is one of the leading issues in neonatal morbidity and mortality, specifically for preterm infants. MRI has established itself as the gold standard in diagnosing HIE; however, it may not always be available in low-resource countries. In such scenarios, cranial sonography may provide a portable and cost-effective alternative for diagnosis; however, diagnostic accuracy varies in the literature.

Objective:

To assess the diagnostic accuracy of cranial sonography for the diagnosis of HIE in clinically suspected preterm neonates, with MRI established as a gold standard.

Methods: This was a cross-sectional validation study conducted over 6 months at the Radiology departments of Bacha Khan Medical College and Mardan Medical Complex. All preterm neonates clinically suspected of having HIE, of which there were 179 in total, were included in the study. Every patient received both cranial ultrasonography and MRI. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall diagnostic accuracy of cranial ultrasound compared with MRI findings were calculated.

Results: Of the 179 neonates, cranial sonography identified 119 of them as having HIE, while MRI noted 126. Cranial ultrasound identified HIE with a sensitivity of 85.7%, specificity of 79.2%, PPV of 90.8%, NPV of 70.0%, and overall diagnostic accuracy of 83.8%. This indicates good overall diagnostic agreement between cranial ultrasound and MRI in terms of HIE.

Conclusion: Cranial Sonography showed good diagnostic performance in the detection of HIE among premature neonates, making it a suitable diagnostic tool when MRI is not available. However, due to its limitations with subtle brain lesions, additional studies that include long-term outcomes will help validate these findings, and would like to be demonstrated with the MRI when feasible.