Cerebral Maturation in Premature Infants: Quantitative Assessment Using MR Imaging
Anne-Marie Childsa,
Luca A. Ramenghia,
Luc Cornettea,
Steven F. Tannera,
Rosemary J. Arthura,
Delia Martineza and
Malcolm I. Levenea
a From the Division of Paediatrics (A-M.C., L.A.R., L.C., M.I.L.) and the Department of Medical Physics and Centre of Medical Imaging Research (S.F.T.), University of Leeds, Leeds, UK; and the Department of Paediatric Radiology, Leeds General Infirmary, Leeds, UK (R.J.A., D.M.).
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FIG 1. Germinal matrix distribution.
A, Axial T2-weighted image from an infant of 23 weeks' gestation (PMA = 24 weeks). Germinal matrix can be seen in the posterior horns (arrowheads), anterior horns (short arrows), and at the caudothalamic notch (long arrows). Score: GM1, B1, C1, M1; TMS = 4.
B, Axial T2-weighted image from infant of 27 weeks' PMA (GA = 25 weeks). Germinal matrix can be seen in same distribution as in A, but is much less evident. Score: GM1, B1, M2, C2; TMS = 6.
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FIG 2. Myelination.
A, Axial T2-weighted image from an infant of 35 weeks' PMA (GA = 35). Myelination can be seen to have started in the posterior limb of the internal capsule (arrows). Score: GM2, B1, M3, C3; TMS = 9.
B, Axial T1-weighted image from an infant of 52 weeks' PMA, too old for this study and only included to illustrate features of myelination. Myelination is seen in anterior and posterior limbs of internal capsule, together with the optic radiation and corona radiata. The unmyelinated white matter is isointense with the gray matter. Score: GM4, B4, M7, C6; TMS = 21.
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FIG 3. Bands of migrating glial cells.
A, Axial T2-weighted image through foramen of Monro in an infant of 35 weeks' PMA (GA = 35 weeks). A broad band of low signal intensity (arrows) with additional narrower bands (arrowheads) can be seen in the frontal periventricular white matter. Score: GM2, B1, M2, C2; TMS = 7.
B, Axial T2-weighted image from an infant of 42 weeks' PMA (GA = 42). There is no band of low signal intensity in the frontal periventricular white matter. Score: GM4, B4, M4, C5; TMS = 17.
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FIG 4. Cortical infolding.
A, Axial T1-weighted image from an infant of 34 weeks' PMA (GA = 34). The frontal and occipital cortices have a similar number of shallow convolutions, and the internal surface of the insula is developing convolutions. The unmyelinated white matter is of low intensity in relation to gray matter. Score: GM2, B1, M3, C3; TMS = 9.
B, Axial T2-weighted image from an infant of 36 weeks' PMA (GA = 36). The frontal and occipital cortices are folded and quite rich in sulci, with deeper sulci evident along the interhemispheric fissure. The insula is more convoluted, and the posterior white matter shows some separation into strands by deeper sulci than in the frontal cortex. Score: GM2, B2, M3, C4; TMS = 11.
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FIG 5. Graph plots TMS against PMA in weeks. Each infant is represented by a single point, although a number of points overlap (ie, four infants with a PMA of 34 weeks have a TMS of 8)
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FIG 6. Graph shows different TMSs for different PMA groups. The graph has been plotted so that each infant is identifiable as a single point. Key to x-axis: numbers in boldface type = PMA (in weeks) of infants within each group; n = total number of infants in each group; µ = mean TMS for each age group
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FIG 7. Bland-Altman plot with average TMS for each infant plotted against the difference in TMS between the observers for that infant. The points have been separated so that each infant can be identified. The solid line represents the mean difference in score (0.07); dotted lines represent 2 SD from the mean (1.12)
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