Table 3.
Singleton-MZ-DZ Comparison of Global and Regional Tissue Volumes (Values Corrected for Gestational Age at MRI and Gender)
| Brain Volumes (all in mm3) | Singleton LSmeans(SE) |
MZ LSmeans(SE) |
DZ LSmeans(SE) |
|---|---|---|---|
| Intracranial Volume | 467925 (3593) | 475535 (5548) | 478996 (4934) |
| Total Brain Volume | 412824 (3054) | 413419 (4787) | 420556 (4131) |
| Total Brain Gray Matter# | 242117 (1936) | 244130 (2799) | 243894 (2256) |
| Total Brain Unmyelinated White Matter | 160883 (1324) | 161945 (2099) | 165517 (1916) |
| Total Brain Myelinated White Matter | 10013 (327) | 10151 (559) | 10511 (439) |
| Total Brain Cerebrospinal Fluid* | 55208 (890) | 61964 (1599) | 58473 (1300) |
| Total cortical volume | 360339 (2681) | 361431 (4255) | 367716 (3798) |
| Cortical Gray Matter# | 201186 (1644) | 203445 (2436) | 202769 (1988) |
| Cortical Unmyelinated White Matter | 152603 (1243) | 153273 (1977) | 156968 (1860) |
| Cerebellum | 25162 (252) | 24529 (462) | 25045 (303) |
| Subcortical Area and Brainstem | 27324 (363) | 27450 (551) | 27831 (408) |
| Prefrontal Gray Matter | 28427 (382) | 27425.39 (642) | 27263 (531) |
| Prefrontal Unmyelinated White Matter | 24350 (282) | 24921 (432) | 24867 (478) |
| Frontal Gray Matter | 43946 (385) | 44104 (638) | 44881 (496) |
| Frontal White Unmyelinated Matter+ | 38193 (361) | 39226 (582) | 39869 (528) |
| Parietal Gray Matter# | 60272 (589) | 60640 (878) | 61511 (667) |
| Parietal Unmyelinated White Matter+ | 48398 (486) | 47921 (744) | 50061 (603) |
| Occipital Gray Matter | 68628 (644) | 69846 (1069) | 69685 (897) |
| Occipital Unmyelinated White Matter | 41666 (427) | 41220 (692) | 42323 (621) |
| Lateral Ventricles | 4400 (147) | 4193 (294) | 4307.09 (244) |
#
p for homogeneity of slopes is < 0.05, test for overall group differences not appropriate;
*
p < 0.01;
+
p < 0.05; LSmeans = Least-squares means