Abstract
Objective
This study aimed to evaluate the utility of early and late magnetic resonance imaging
(MRI) in infants with neonatal encephalopathy (NE) after therapeutic hypothermia (TH),
and to determine the concordance between magnetic resonance spectroscopy (MRS) and
early MRI findings.
Study Design
We conducted a retrospective, observational study including encephalopathic neonates
born between 2017 and 2023 at two regional perinatal centers. All subjects underwent
early diffusion-weighted MRI (DWI) with or without MRS (day: 4–5), and late conventional
T1/T2-weighted MRI (day: 12–14). Both MRIs were assigned an injury severity score
based on the National Institute of Child Health and Human Development (NICHD) neonatal
research network (NRN) pattern of injury, reflecting the injury apparent on the MR
modality obtained. MRS injury was defined as the presence of a lactate peak.
Results
The majority of the cohort (n = 98) was moderately encephalopathic (78%). Early and late MR imaging was performed
at an average of 5.7 and 13.6 days, respectively. Fifteen percent of infants had evidence
of hypoxic-ischemic (HI) injury on early imaging only, and 6% on late imaging only.
Forty percent of infants exhibited a change in NICHD score severity between early
and late MRI. Twenty-three infants (24%) were found to have a milder injury and 16
(16%) were found to have more severe injury on late imaging, when scores were compared
with early imaging scores. The concordance of injury between early MRS and MRI was
62.5%. Among the cases of discordant MRI/MRS, MRS detected additional injury in 70%
of cases, and MRI detected additional injury in 30% of cases.
Conclusion
Both early and late imaging are important to fully define injury and provide accurate
neurodevelopmental prognoses in cases of encephalopathic infants following TH. Failure
to perform imaging at two intervals would have potentially resulted in missed diagnoses
in 6 to 15% of cases and misestimation of injury in up to 40% of cases.
Key Points
-
Early and late neuroimaging is important for accurate neurodevelopmental prognostication
of encephalopathic neonates.
-
The NICHD NRN MRI scoring system is a helpful tool for clinical practice.
-
MR spectroscopy shows promise for HI injury but requires more validation.
Keywords
neonatal encephalopathy - magnetic resonance imaging - magnetic resonance spectroscopy
- neuroimaging - neurodevelopmental prognostication
