The course of apparent diffusion coefficient values following perinatal arterial ischemic stroke

Area of Science:

• Neuroimaging
• Pediatric Neurology
• Radiology

Background:

• Diffusion weighted MR imaging (DWI) is crucial for diagnosing perinatal arterial ischemic stroke (PAIS) in the acute phase.
• Apparent diffusion coefficient (ADC) derived from DWI quantifies diffusion restriction, aiding in stroke assessment.

Purpose of the Study:

• To identify changes in ADC values in the acute phase following PAIS.
• To correlate ADC values with postnatal age and stroke severity.

Main Methods:

• Studied 36 infants with confirmed PAIS within the first ten days of life.
• Determined ADC values in the ischemic core (iADC) and calculated ADC ratios (rADC) against the contralateral hemisphere.
• Correlated iADC and rADC values with postnatal age and stroke characteristics.

Main Results:

• Observed a non-linear increase in iADC and rADC values over the first ten days.
• Larger middle cerebral artery strokes were associated with lower iADC and rADC values.
• rADC values normalized after postnatal day seven.
• Lower rADC values compared to hypoxic ischemic encephalopathy suggest more severe PAIS injury.

Conclusions:

• DWI shows decreased ADC values in PAIS with a non-linear increase during the first week, followed by pseudonormalization after day 7.
• The findings limit the utility of DWI for assessing PAIS to the first week of life.
• Lower ADC values in PAIS compared to hypoxic ischemic encephalopathy likely indicate more severe injury.