🧠 Brain Myelination Assessment (MRI)
Look up expected MRI T1/T2 signal at key brain sites by age — preterm through preschool — to judge whether myelination is age-appropriate. Free, browser-based reference for radiologists, neonatologists and pediatric neurologists.
Myelination proceeds caudal→rostral, dorsal→ventral, central→peripheral, and sensory before motor pathways.
Brain Myelination Assessment (MRI)
When to use
Quick reference during reporting or review of pediatric/neonatal brain MRI, when judging whether a structure's signal is age-appropriate or possibly delayed. Not a diagnostic algorithm — myelination is a continuous biological process and published milestones vary slightly by series and reader.
How it works
No formula — a curated lookup table built from published normal myelination milestones (Rutherford; Barkovich; AJNR/HKJR myelination-clock reviews), cross-referenced by anatomic site and age band.
Key points
- Myelination proceeds caudal→rostral, dorsal→ventral, central→peripheral, and sensory before motor pathways.
- PLIC, brainstem and cerebellar peduncles myelinate earliest (often visible in preterm infants from ~32–36 weeks GA); frontal association white matter is the last to mature, sometimes not appearing until 10–13 months.
- T1 signal change typically precedes T2 signal change at the same site by 1–5 months — relying on T2 alone can underestimate true myelination stage.
- Marked delay or absence of signal at an early-myelinating site (especially PLIC) for the stated age is a recognized marker of brain injury (e.g. HIE, PVL) and warrants clinical correlation.
- After ~2 years, T2-based milestones lose precision; overall developmental assessment should guide interpretation alongside imaging.
References
- Rutherford MA. MRI of the Neonatal Brain. Saunders, 2002.
- Barkovich AJ, Raybaud C. Pediatric Neuroimaging, 6th ed. Wolters Kluwer.
- Welker KM, Patton A. Assessment of normal myelination with magnetic resonance imaging. Semin Neurol. 2012;32(1):15-28.