Appendix III.

MRI Brain Development/Maturity Scoring System

Category*	Designation/Score	Definition
Myelination(M)	M1	Myelination evident in the brainstem, cerebellar peduncle, inferior colliculus, cerebellar vermis
	M2	M1 + Subthalamic nucleus, globus pallidus, ventrolateral thalamus
	M3	M2 + Caudal portion of the Posterior Limb of the Internal Capsule (PLIC)
	M4	M3 + Complete PLIC
	M5	M4 + optic radiation
	M6	M5 + Corona radiata
	M7	M6 + anterior limb of internal capsule
Cortical Infolding [C]	C1	Frontal and occipital cortex completely smooth, insula wide open; thin bright cortical rim on T1, generally low-intensity white matter (WM) on T1
	C2	Frontal cortex still very smooth, some sulci evident in occipital cortex; insula still wide with almost smooth internal surface; WM low intensity on T1
	C3	Frontal and occipital cortex similar number of convolutions; frontal sulci still quite shallow; internal surface of insula more convoluted; WM still somewhat low intensity on T1
	C4	Frontal and occipital ctex folded and rich in sulci; frontal sulci obvious along interhemispheric fissure; occipital WM separated into strands by deeper sulci; insula completely infolded; WM still distinguishable from gray matter on T1
	C5	Frontal and occipital WM separated into strands by deeper sulci; insula completely infolded; WM still distinguishable from gray matter on T1
	C6	As above but WM now isointense with gray matter on T1
Germinal Matrix (GM)	GM1	Matrix seen in posterior horn, caudothalamic notch (CTN) and anterior horns of the lateral ventricles
	GM2	Matrix seen at CTN and anterior horns of the lateral ventricles
	GM3	Matrix seen in the anterior horns only
	GM4	No Germinal matrix evident
Bands of Migrating Glial Cells (B)	B1	Broad band with additional narrower bands evident
	B2	Broad band alone
	B3	Narrow band alone
	B4	No bands seen

^*From Childs AM AJNR 2001;22:1577 (ref ¹⁹)