Figure 1.
Manually segmented representative axial T2w slices (# 16–31 of 44 total slices) beginning inferiorly with the amygdalae (cream color), hippocampi (green), brain stem (turquoise), cerebellum (copper) (A–C) and progressing superiorly with thalamic (orange), lenticular (pink), accumbens (blue), and caudate nuclei (lavender) and corpus callosum (yellow) (D–O).
Final 3-dimensional axial and sagittal oblique models of all nine segmented structures (P and Q).
Figure 2.
Mid-axial T2w slice on the left highlighting periventricular regions of white matter signal abnormalities (short purple arrows) that the automated segmentation program consistently misclassified as CSF (light blue regions on segmented image on the right).
Occasionally subarachnoid CSF was misclassified as WM (long red arrows).
Figure 3.
Commercially available Analyze (white boxes) and in-house developed (IDL environment; gray boxes) segmentation programs were integrated seamlessly to permit various preprocessing and segmentation steps.
The combined manual structural and automated tissue maps were merged in IDL and exported to Analyze for final manual correction and volume calculations.
Table 1.
Mean volumes and 95% confidence limits (CL) of manually segmented structures in 20 high risk ELBW infants studied at 38 weeks PMA.
Table 2.
Intra-rater reliability of manually segmented cerebral structures and tissues volumes.
Table 3.
Inter-rater reliability of manually segmented cerebral structures and tissues volumes.
Table 4.
Mean tissue volumes and 95% CL (mm3) using automated, semi-automated, and the reference manually segmented approaches in 10 high risk ELBW infants studied at 38 weeks PMA.
Figure 4.
Mean and standard deviations of automated (left) and semi-automated (right) segmentation accuracy and bias measures, including similarity index (SI), correct estimation index (CEI), over estimation index (OEI), and under estimation index (UEI) for cerebral gray matter (light gray), cerebral white matter (black), and CSF (gray).
Figure 5.
A single mid-axial slice exemplifies results at various stages of processing, beginning with unsegmented conventional axial T2 (A) and proton density weighted images (B), automated three tissue segmentation of cerebral GM (gray), cerebral WM (white), and CSF (light blue) (C), manual structural segmentation output (D), combined automated and manual map without correction (E), and final map following manual correction, including relabeling of WM hyperintensities as WMSA (purple) (F).
A 3-dimensional rendering at the same midbrain level displays the relationship of all 13 segmented regions (G).