Table 1.
Demographic Measures: Preterm and Full Term Groups.
Fig 1.
Tractography of 18 major cerebral white matter tracts.
The left hemispheric cerebral tracts are displayed on mid-sagittal T1 images from a representative full term subject (a, b) and a representative preterm subject (c, d). Right hemisphere tract renderings not shown. Panels a and c illustrate the following tracts: Arcuate Fasciculus (Arc) = light blue; Corticospinal Tract (CST) = dark blue; Forceps Major (FMajor) = brown; Forceps Minor (FMinor) = dark red; Uncinate Fasciculus (UF) = yellow. Panels b and d illustrate the following tracts: Anterior Thalamic Radiation (ATR) = purple; Cingulum (Cing) = magenta; Inferior Fronto-occipital Fasciculus (IFOF) = red; Inferior Longitudinal Fasciculus (ILF) = orange; Anterior Superior Longitudinal Fasciculus (aSLF) = green. Dashed lines represent the location of the regions of interest (ROIs) used to isolate each cerebral tract; ROI 1, white; ROI 2, black.
Fig 2.
Tract profiles in the preterm and full term groups.
Mean FA profiles are shown for each of the cerebral tracts depicted in Fig 1A and 1C, for the full term group (solid green line) and the preterm group (solid purple line). Visualized tract profiles: left (a) and right (b) arcuate fasciculus; left (c) and right (d) corticospinal tract; (e) forceps major and (f) forceps minor; and left (g) and right (h) uncinate fasciculus. FA values are plotted for 30 equidistant nodes between the two ROIs used to isolate the core of each tract. For all tracts, node 0 corresponds to ROI-1 and node 30 corresponds to ROI-2. Dashed lines indicate ± 1 standard error of the mean. Tracts with significant Group by Location interactions in the omnibus test are indicated with a blue *. Shaded gray background indicates a tract segment where mean FA of the PT is significantly decreased compared to the FT group. Tract renderings from a representative full term subject pictured in Fig 1A and 1B are shown next to each profile for illustration purposes. Light shading and white outline on the tract rendering indicates the approximate location of the periventricular zone in this participant, and the node numbers defining this zone are indicated next to the rendering. Arc = Arcuate Fasciculus; CST = Corticospinal Tract; FMajor = Forceps Major; FMinor = Forceps Minor; UF = Uncinate Fasciculus; PT = Preterm; FT = Full term; FA = Fractional Anisotropy; L = Left; R = Right.
Fig 3.
Tract profiles in the preterm and full term groups (continued).
Color coding and visualization scheme same as in Fig 2 (see caption to Fig 2). Visualized tract profiles: left (a) and right (b) anterior thalamic radiations; left (c) and right (d) cingulum; left (e) and right (f) inferior fronto-occipital fasciculus; left (g) and right (h) inferior longitudinal fasciculus; and left (i) and right (j) anterior superior longitudinal fasciculus. Dashed lines indicate ± 1 standard error of the mean. FA values are plotted for 30 equidistant nodes between two ROIs used to isolate the core of each tract. For all tracts Node 0 corresponds to ROI-1 and Node 30 corresponds to ROI-2. Tracts with significant main effect of Group in the omnibus test are indicated with a red *. Tracts with significant Group by Location interactions in the omnibus test are indicated with a blue *. Shaded gray regions indicate tract segments where mean FA of the PT group is significantly decreased than the FT group. Shaded light brown regions indicate tract segments where mean FA of the FT group is significantly increased than the PT group. Tract renderings from a representative full term subject pictured in Fig 1A and 1B are shown next to each profile for illustration purposes. Light shading and white outline on the tract rendering indicates the approximate location of the periventricular zone in this participant, and the node numbers defining this zone are indicated next to the rendering. ATR = Anterior Thalamic Radiation; Cing = Cingulum; IFOF = Inferior Fronto-occipital Fasciculus; ILF = Inferior Longitudinal Fasciculus; aSLF = Anterior Superior Longitudinal Fasciculus; PT = Preterm; FT = Full term; FA = Fractional Anisotropy; L = Left; R = Right.
Table 2.
ANCOVA results for the comparison of preterm and full term FA profiles.
Table 3.
Mean Tract FA of 18 cerebral white matter tracts in Preterm and Full Term groups.
Table 4.
Locations along the white matter tracts in which Preterm and Full Term groups showed significant group differences in Fractional Anisotropy.
Table 5.
Mean AD and RD within segments of the white matter tracts in which group differences in FA reached statistical significance.