Prominent signal intensity of T₁/T₂ prolongation in subcortical white matter of the anterior temporal region on conventional screening MRI of late preterm infants with normal development

Abstract 

Purpose

This study discusses prominent signal intensity of T₁/T₂ prolongation of subcortical white matter within the anterior temporal region in premature infant brains that radiologists may encounter when interpreting conventional screening MRIs.

Materials and Methods

T₁- and T₂-weighted images of 69 preterm and term infants with no neurological abnormalities or developmental delays were evaluated retrospectively for areas of prominent signal intensity of T₁/T₂ prolongation in white matter. We measured signal intensities of anterior temporal white matter, deep temporal white matter, frontopolar white matter and subcortical white matter of the precentral gyrus. We accessed chronological changes in signal intensity in the anterior and deep temporal white matter. We also analyzed variance tests among the signal intensity ratios to the ipsilateral thalamus of white matter areas by gestational age.

Results

There was high frequency of prominent signal intensity of T₁/T₂ prolongation in the temporal tip, particularly at a gestational age of 36–38 weeks. Signal intensity ratio of the anterior temporal white matter was lower on T₁-weighted images and higher on T₂-weighted images, and the finding became less prominent with increasing gestational age. The signal intensity ratios of anterior temporal white matter at a gestational age of 36–37 weeks and 38–39 weeks were significantly different from other regions.

Conclusion

Prominent signal intensity of T₁/T₂ prolongation of subcortical white matter of the anterior temporal region is seen in normal premature infants, especially those at 36–39 gestational weeks. Although it is a prominent finding, radiologists should understand that these findings do not represent a pathological condition.

Keywords: Newborn, Premature, MRI, Development