Terminal Zones of Myelination

January 24, 2011


E-Pearl of the Week

Brought to you by the Resident and Fellow Section of the journal Neurology®.

January 24, 2011

White matter T2 hyperintensities can be difficult to interpret in brain MRIs of children. Peri-ventricular and peri-trigonal hyperintensities are typical findings in periventricular leukomalacia and white matter injury, yet these findings are also seen in normal children as terminal zones of myelination throughout the first two decades of life. A specific MRI finding can help differentiate between these and prevent unnecessary follow-up imaging and further testing.

In normal children, there is a thin layer of myelinated white matter (isointense to the normal white matter on T2/FLAIR) present between the trigone of the ventricle and the terminal zones, while in children with periventricular leukomalacia, this layer of normally myelinated white matter is absent and the hyperintense lesion will extend all the way to the surface of the venticle.


    Barkovich AJ. Pediatric Neuroimaging, 4th Ed. Philadelphia: Lippincott Williams & Wilkins; 2005: 36-37.

Submitted by Thomas Q. Reynolds, DO

Dr. Reynolds reports no disclosures.

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