🧠 MRI Myelination Assessment (Neonatal / Infant)
Mark T1/T2 MRI findings structure by structure and check them against normal myelination milestones, from preterm through preschool, using an onset (☆ some normal infants) – completion (★ all normal infants) two-stage window to flag delayed myelination by corrected or gestational age. Free, browser-based reference for radiologists, neonatologists and pediatric neurologists.
The two-stage window reduces false positives: absence before onset is normal, and delay is only flagged when signal is still absent past the age by which all normal infants show it.
Paste the link in Slack, Teams, X, or LinkedIn — the preview image comes from this page’s Open Graph card.
When to use
Use during reporting or review of preterm/neonatal/infant brain MRI to judge whether each structure's signal is appropriate for the corrected age, and to surface regions that appear delayed. This is an interactive, structure-by-structure assessment — click Open interactive assessment to enter the age, choose the sequence and mark each finding.
How it works
Each site has an onset (☆) – completion (★) window for T1 hyperintensity and T2 hypointensity. Absence before the onset age is normal; within the onset window it may be present or absent in normal infants (indeterminate); absence past the completion age is scored as delay (mild if ≤2 months over, marked if >2 months over).
Key points
- The two-stage window reduces false positives: absence before onset is normal, and delay is only flagged when signal is still absent past the age by which all normal infants show it.
- T1 signal change precedes T2 change at the same site; choose the sequence that matches the infant's age for the most informative read.
- Use corrected age (not chronological age) for preterm infants to avoid apparent (false) delay.
- PLIC and brainstem should be myelinated at term; splenium precedes genu; frontal peripheral WM and peripheral cerebellar WM mature latest (T2 up to 12–18 months) with the widest individual variation.
- An isolated structure within its onset window, or mildly delayed, is often normal variation — interpret with symmetry, developmental assessment and follow-up.
- Marked diffuse delay warrants consideration of HIE sequelae, leukodystrophy, congenital infection or metabolic disease.
References
- Jiangsu Radiology Society, Pediatric Group — Advances in Pediatric Imaging & Radiation Protection teaching materials: normal term-infant myelination timetable / T1WI·T2WI appearance-by-month star chart.
- Barkovich AJ, Kjos BO, Jackson DE, Norman D. Normal maturation of the neonatal and infant brain: MR imaging at 1.5 T. Radiology 1988.
- van der Knaap MS, Valk J. Magnetic Resonance of Myelination and Myelin Disorders, 3rd ed. Springer, 2005.
- Arthurs OJ, et al. Normal myelination on MRI: a pictorial review. Pediatr Radiol 2017.
Frequently asked questions
- What is MRI Myelination Assessment (Neonatal / Infant)?
- Mark T1/T2 MRI findings structure by structure and check them against normal myelination milestones, from preterm through preschool, using an onset (☆ some normal infants) – completion (★ all normal infants) two-stage window to flag delayed myelination by corrected or gestational age. Free, browser-based reference for radiologists, neonatologists and pediatric neurologists.
- How is MRI Myelination Assessment (Neonatal / Infant) calculated? What is the core formula?
- Each site has an onset (☆) – completion (★) window for T1 hyperintensity and T2 hypointensity. Absence before the onset age is normal; within the onset window it may be present or absent in normal infants (indeterminate); absence past the completion age is scored as delay (mild if ≤2 months over, marked if >2 months over).
- When is MRI Myelination Assessment (Neonatal / Infant) used?
- Use during reporting or review of preterm/neonatal/infant brain MRI to judge whether each structure's signal is appropriate for the corrected age, and to surface regions that appear delayed. This is an interactive, structure-by-structure assessment — click Open interactive assessment to enter the age, choose the sequence and mark each finding.
- What are the key clinical points for MRI Myelination Assessment (Neonatal / Infant)?
- The two-stage window reduces false positives: absence before onset is normal, and delay is only flagged when signal is still absent past the age by which all normal infants show it. T1 signal change precedes T2 change at the same site; choose the sequence that matches the infant's age for the most informative read. Use corrected age (not chronological age) for preterm infants to avoid apparent (false) delay. PLIC and brainstem should be myelinated at term; splenium precedes genu; frontal peripheral WM and peripheral cerebellar WM mature latest (T2 up to 12–18 months) with the widest individual variation. An isolated structure within its onset window, or mildly delayed, is often normal variation — interpret with symmetry, developmental assessment and follow-up. Marked diffuse delay warrants consideration of HIE sequelae, leukodystrophy, congenital infection or metabolic disease.
- What are the limits and cautions when using MRI Myelination Assessment (Neonatal / Infant)?
- For licensed clinicians and clinical researchers. Interpret results with history, investigations and local protocols; not a diagnosis or prescription, and not a substitute for multidisciplinary decision-making or local guidelines.