Agyri-Packygyri
Agyri-Packygyri
Agyri-PakygyriLissencephaly
Developing fetal brain normally appears smooth or “agyric” until 16th to 17th week of intrauterine life. Lissencephaly refers to absent or poor sulcation (Figure ). It can be complete (agyria) or incomplete (agyria-pachygyria). Type I lissencephaly shows the typical figure eight configuration of brain with colpocephaly, thickened cortex, smooth gray-white matter interface, flat broad gyri and shallow sylvian fissures. Type II lissencephaly on MR shows thickened cortex having polymicrogyric appearance . Type I lissencephaly is associated with Miller-Dieker syndrome while type II lissencephaly is associated with Walker-Warburg syndrome.
Figure : Lissencephaly. A, Type 1 lissencephaly showing shallow sylvian fissures, absence of gyri and thickened cortex (Arrow). B, Pachygyria. Note the thick cortex, sparse flat gyri and figure of eight appearance. C, This spin echo MR image shows pachygyric brain. Note the paucity of gyri affecting mainly the occipital regions (Arrows). Gyri are also sparse in right fronto-parietal region. Sylvian fissures are shallow.
Developing fetal brain normally appears smooth or “agyric” until 16th to 17th week of intrauterine life. Lissencephaly refers to absent or poor sulcation (Figure ). It can be complete (agyria) or incomplete (agyria-pachygyria). Type I lissencephaly shows the typical figure eight configuration of brain with colpocephaly, thickened cortex, smooth gray-white matter interface, flat broad gyri and shallow sylvian fissures. Type II lissencephaly on MR shows thickened cortex having polymicrogyric appearance . Type I lissencephaly is associated with Miller-Dieker syndrome while type II lissencephaly is associated with Walker-Warburg syndrome.
Figure : Lissencephaly. A, Type 1 lissencephaly showing shallow sylvian fissures, absence of gyri and thickened cortex (Arrow). B, Pachygyria. Note the thick cortex, sparse flat gyri and figure of eight appearance. C, This spin echo MR image shows pachygyric brain. Note the paucity of gyri affecting mainly the occipital regions (Arrows). Gyri are also sparse in right fronto-parietal region. Sylvian fissures are shallow.
(A)
(B)
(C)Reference:The Internet Journal of Radiology™ ISSN: 1528-8404
Radiopaedia.org.
No comments:
Post a Comment