Interpolation Algorithm for Motion Vector Field of CTA Image and Accelerated Implementation Based on Uniform Grid and Multi-level B-spline / 中国医疗器械杂志

In order to solve the problems of slow operation speed and low registration accuracy of thin plate spline (TPS) interpolation method for motion vector field in coronary computed tomography angiography (CTA), a multi-level B-spline interpolation method (MBS) with uniform grid is proposed. On the one hand, the interpolation method used local B-spline to refine the sparse mesh layer by layer in a multiscale way to improve the accuracy of registration. On the other hand, it used the splitting matrix method to interpolate the motion vector field, greatly reducing the operation time of interpolation. The experimental results show that the proposed method can be used for CTA image registration efficiently.

Morfología de las especies de Hyphessobrycon (Characiformes: Characidae), grupo heterorhabdus, en Colombia

Morphology of the species Hyphessobrycon, heterorhabdus group (Characiformes: Characidae) in Colombia. Hyphessobrycon is the most numerous and morphologically complex genus of Characidae, and includes 18 species reported for Colombia, from which thirteen belong to the heterorhabdus-group different methods have been proposed for species identification within this genus. This study used these species to undertake a morphogeometric analysis by the Box Truss and Thin Plate Splin (TPS) methods; 13 homologous landmarks type I and three type II were used. The result of cluster analysis indicated that these species are represented by two big groups: robust and thin. The uniform and non uniform components, and the principal warps (WP) and partial warps (Wparc), described the shape changes related to body depth, involving relative displacements of the appendicular skeleton and the cephalic region. All species were characterized by allometric growth with the exception of Hyphessobrycon mavro, who presented an isometry between the landmarks 6-7. Two new measures are proposed for species discrimination in the group (snout-supraoccipital spine distance and supraoccipital spine-pelvic fin). Rev. Biol. Trop. 59 (2): 709-725. Epub 2011 June 01.

El género Hyphessobrycon incluye dieciocho especies reportadas para Colombia de las cuales 13 son miembros del grupo heterorhabdus; con las mismas, se realizó un análisis morfogeométrico por medio del Método de Cerchas (Box Truss) y Láminas Delgadas (TPS). Se usaron 13 hitos homólogos tipo I y tres tipo II. El resultado del análisis cluster, llevado a cabo con cada una de las metodologías indicó que estas especies están representadas en dos grandes grupos: robustas y delgadas. Las deformaciones parciales, los componentes uniformes, no uniformes, Warps principales y Warps parciales describieron cambios de la forma relacionados con la profundidad del cuerpo e involucraron desplazamientos relativos del esqueleto apendicular y de la región cefálica. Todas las especies se caracterizan por presentar crecimiento alométrico excepto Hyphessobrycon mavro con isometría entre los hitos 6-7. Se plantean dos nuevas medidas discriminantes (hocico-supraoccipital y supraoccipital-aleta pélvica) para las especies del grupo.