Diploic vessels and computed tomography: Segmentation and comparison in modern humans and fossil hominids.
OBJECTIVE
The diploic channels appear to be more developed in humans than in nonhuman primates, suggesting they may be relevant in evolutionary biology. This study is aimed at providing a segmentation procedure for diploic channels and CT analysis, a quantitative description of their variation in modern humans, and paleoanthropological case-studies.


METHODS
CT data were used for the 2D and 3D visualization, rendering, and measure, of diploic channels in modern and fossil hominids. We analyzed 20 modern human skulls and three Neanderthals. The effect of different resolution factors was evaluated. A specific protocol was designed to segment the vascular network and localize the main branches, reducing the noise of the cancellous bone.


RESULTS
We provide a quantitative description of the frontal, parietal, and occipital diploic networks in modern humans and in three Neanderthals. There is a correlation in the degree of vascularization among the different vault areas. No side differences can be detected. The diploic network is commonly connected with the meningeal artery at the temporal fossa, with the emissary veins at the occipital bone, and with the venous sinuses at the parieto-occipital areas. The channels are more developed in the parietal areas. The three Neanderthals show a vascular development, which is in the lower range of the modern human variation.


CONCLUSIONS
Modern humans display a large variation in their morphological patterns, being the parietal area the most vascularized. The pattern of the diploic channels may be relevant in anthropology, medicine, and paleontology, taking into account their possible involvement in thermoregulation.
Área de Prehistoria, Universitat Rovira I Virgili, Tarragona, Spain.|Institut Català De Paleoecologia Humana I Evolució Social (IPHES), Tarragona, Spain.
Gizéh
G
Rangel de Lázaro
Departamento de Biología, Universidad Autónoma De Madrid, Spain.
José Manuel
JM
de la Cuétara
Antropologické Oddělení, Univerzita Karlova and Národní Muzeum, Prague, Czech Republic.
Hana
H
Píšová
Área de Prehistoria, Universitat Rovira I Virgili, Tarragona, Spain.|Institut Català De Paleoecologia Humana I Evolució Social (IPHES), Tarragona, Spain.
Carlos
C
Lorenzo
Grupo de Paleobiología, Centro Nacional De Investigación Sobre La Evolución Humana (CENIEH), Burgos, Spain.
Emiliano
E
Bruner
D000328:Adult; D000818:Animals; D000885:Anthropology, Physical; D005580:Fossils; D006801:Humans; D059125:Neanderthals / Q000033:anatomy & histology; D012886:Skull / Q000033:anatomy & histology / Q000098:blood supply / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed
cranial anatomy; digital anatomy; diploe; paleoanthropology