IFEG   20353
INSTITUTO DE FISICA ENRIQUE GAVIOLA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
X-RAY MICROMOGRAPHY ON BIRDS: THE ACCESS TO AN INADVERTENT WORLD
Autor/es:
TAMBUSSI, C.P.; TIRAO, G.; DEGRANGE, F.J.
Lugar:
Carlos Paz
Reunión:
Congreso; XIV Latin American Seminar of Analysis by X-Ray Techniques; 2014
Institución organizadora:
XIV Latin American Seminar of Analysis by X-Ray Techniques
Resumen:
The cranial cavity of birds is almost completely filled by the brain, so the internal surface of the cranial bones closely reflects brain anatomy including the blood vessel and nerves. 3D models obtained from the CTs of skulls can be built for qualitative (cognitive, sensory or ecological abilities) and quantitative (overall brain sizes or particular brain areas) analysis. Conventional Hospital CT has been used quite extensively to examine skeletal characters and some soft tissues in birds [1,2]. However, it is not possible to obtain good models of small specimens or deep details of small structures such as the inner ear. X-ray microtomography opens the doors to a completely empty space of knowledge so far. In Argentina, obtaining micro CT is possible at National University of Córdoba. The x-ray micro CT was entirely developed by researchers of Grupo de Espectroscopía Atómica y Nuclear (GEAN) at Facultad de Matemática, Astronomía y Física (FaMAF). This equipment allows to obtain 2D and 3D images up to 20 cm x 20 cm with resolutions of 194 m. It is also possible to maximize the quality of the images from the control of main parameters involved in the image acquisition: conformation of the X-ray beam (spatial and spectral distribution), counting statistics, number of projections, relative position of the sample and detector. To evaluate the potential differences of the models obtained with one or other equipment, specimens of Guira Cucko (skull lenght 60mm) were scanned into two apparatus and virtual 3D models were made with the same software (Materialise Mimics) and protocol. The model of the micro-CT (~238 slices) allowed visualization of the dorsal parts of the brain (wulst associated with proprioceptive abilities), the vascular system (carotids), the cephalic nerves, pituitary and inner ear. From the latter it is possible to calculate hearing capabilities. In the model constructed from the conventional CT (~89 slices), these structures are not discernable. The information obtained is valuable not only to better understand the animal biology but to establish patterns of change and evolutionary rates in a comparative context. Ultimately, the use of high resolution scanners has enormous applications in biology and paleobiology.