🧠 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.
Paste the link in Slack, Teams, X, or LinkedIn — the preview image comes from this page’s Open Graph card.
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.
Worked calculation
The values below come from this tool's own example placeholders and are computed server-side with the formula shown on this page, so the arithmetic can be checked quickly. It demonstrates how to substitute values only — it is not clinical advice and not a real case.
| Age group | Preterm (28–36 weeks GA) |
|---|---|
| Anatomic site | Posterior limb of internal capsule (PLIC) |
→Posterior limb of internal capsule (PLIC) · Preterm (28–36 weeks GA)See expected findings below
- T1WI appearance：T1 hyperintensity typically begins by 32–36 weeks GA (preterm infants often show this earlier relative to corrected age than term infants)
- T2WI appearance：T2 hypointensity usually appears around 35–36 weeks GA; little new myelination is seen between 28–35 weeks GA
- Interpretation note：PLIC is among the earliest sites to myelinate; absence at 36 weeks GA should raise concern.
Frequently asked questions
- What is 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.
- How is Brain Myelination Assessment (MRI) calculated? What is the core formula?
- 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.
- When is Brain Myelination Assessment (MRI) used?
- 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.
- What are the key clinical points for Brain Myelination Assessment (MRI)?
- 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.
- What are the limits and cautions when using Brain Myelination Assessment (MRI)?
- 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.
- How is Brain Myelination Assessment (MRI) calculated in practice? Can you show a worked example?
- Inputs: Age group Preterm (28–36 weeks GA), Anatomic site Posterior limb of internal capsule (PLIC) → Result: Posterior limb of internal capsule (PLIC) · Preterm (28–36 weeks GA) See expected findings below（T1WI appearance: T1 hyperintensity typically begins by 32–36 weeks GA (preterm infants often show this earlier relative to corrected age than term infants), T2WI appearance: T2 hypointensity usually appears around 35–36 weeks GA; little new myelination is seen between 28–35 weeks GA, Interpretation note: PLIC is among the earliest sites to myelinate; absence at 36 weeks GA should raise concern.）