Mimickers of hypoxic-ischaemic brain injury in term neonates: What the radiologist should know

Patterns of neonatal hypoxic-ischaemic brain injury (HIBI) are fairly well known. There are, however, other diagnoses with imaging patterns that may mimic HIBI. A review of MRI studies was conducted for children with suspected cerebral palsy, correlated with prior imaging, clinical details and laboratory tests where available. In the 63 identified cases, imaging features were, in many cases, very similar to the known patterns of HIBI. The alternative diagnoses can be classified as developmental, vascular, chromosomal, infections, metabolic disorders, and congenital syndromes. These findings are described in this pictorial essay. The potential mimickers of HIBI described in this essay can demonstrate similar imaging appearances to HIBI.

Contribution

There are multiple possible causes of neonatal encephalopathy other than hypoxic-ischaemic encephalopathy. Many conditions may mimic HIBI, each of which can be associated with significant morbidity. It is prudent for the reporting radiologist to be aware of these alternate clinico-radiological diagnoses.

Neuroquantification enhances the radiological evaluation of term neonatal hypoxic-ischaemic cerebral injuries

Background

Injury patterns in hypoxic-ischaemic brain injury (HIBI) are well recognised but there are few studies evaluating cerebral injury using neuroquantification models.

Objectives

Quantification of brain volumes in a group of patients with clinically determined cerebral palsy.

Method

In this retrospective study, 297 children with cerebral palsy were imaged for suspected HIBI with analysis of various cerebral substrates. Of these, 96 children over the age of 3 years with a clinical diagnosis of cerebral palsy and abnormal MRI findings underwent volumetric analyses using the NeuroQuant® software solution. The spectrum of volumetric changes and the differences between the various subtypes (and individual subgroups) of HIBI were compared.

Results

Compared with the available normative NeuroQuant® database, the average intracranial volume was reduced to the 1st percentile in all patient groups (p < 0.001). Statistically significant differences were observed among the types and subgroups of HIBI. Further substrate volume reductions were identified and described involving the thalami, brainstem, hippocampi, putamina and amygdala. The combined volumes of five regions of interest (frontal pole, putamen, hippocampus, brainstem and paracentral lobule) were consistently reduced in the Rolandic basal ganglia-thalamus (RBGT) subtype.

Conclusion

This study determined a quantifiable reduction of intracranial volume in all subtypes of HIBI and predictable selective cerebral substrate volume reduction in subtypes and subgroups. In the RBGT subtype, a key combination of five substrate injuries was consistently noted, and thalamic, occipital lobe and brainstem volume reduction was also significant when compared to the watershed subtype.

Contribution

This study demonstrates the value of integrating an artificial intelligence programme into the radiologists' armamentarium serving to quantify brain injuries more accurately in HIBI. Going forward this will be an inevitable evolution of daily radiology practice in many fields of medicine, and it would be beneficial for radiologists to embrace these technological innovations.

Has the incidence of hypoxic ischaemic encephalopathy in Queensland been reduced with improved education in fetal surveillance monitoring?

BACKGROUND

Hypoxic ischaemic encephalopathy (HIE) is secondary to intrapartum asphyxia and the fifth largest cause of death of children under five. Incorrect use and interpretation of intrapartum cardiotocographs has been identified as a contributing factor to the development of HIE. Therefore, RANZCOG introduced the Fetal Surveillance Education Program (FSEP) to improve education and practice of intrapartum care.

AIM

To investigate the incidence of HIE throughout Queensland between 2003 and 2011 during the introduction and implementation of RANZCOG FSEP.

METHODS

The incidence of HIE admissions at each hospital in Queensland (2003-2011) was collated from Queensland Health Statistics Centre. RANZCOG FSEP provided data regarding course attendees throughout Queensland (2006-2011). Hospitals were grouped into four regions. Statistical analysis was conducted using Stata(TM) (version 12.0) - data appeared to follow a damped harmonic model.

RESULTS

The posteducation (2006-2011) HIE rate was significantly lower (P = 0.02) than the pre-education (2003-2005) rate. The final model predicted a stabilisation of HIE occurrence rate at approximately 160 events/100,000 live births by 2012. This rate was stable if the level of education was maintained but rose back to the initial rate of 250 events/100,000 live births if the education participation was discontinued.

CONCLUSIONS

This study identified a significant reduction in the incidence of HIE--a potentially life-threatening newborn condition--between 2003 and 2011, during and following FSEP implementation. Notwithstanding the inevitable limitations of state-based data collection, these results are encouraging. For such improvements to be sustained, education must reach all staff engaged in intrapartum care and be regularly repeated.