Optimal surface property for three-dimensional echo visualization
Shunsuke Asakura1, Saki Nishikawa1, Kazumasa Orihashi2
1Center for Innovative and Translational Medicine, Kochi Medical School, Nankoku, Japan.
Purpose:
Three-dimensional (3D) echo is a useful modality to guide off-pump intracardiac surgery, and this study aimed to determine the optimal surface property for minimizing echo dropout and grating lobes.
Methods:
A total of 13 specimens were examined. The specimens were scanned while they were rotated from 0° to 90°, and en face views were recorded in the 3D zoom mode. Changes in brightness were compared with the surface profile, which was traced from microscopic images. The brightness and size of grating lobes were also examined.
Results:
Decreases in brightness that were observed at a large rotation angle were classified into three groups (sharp, moderate, and gradual), and variation in the effective reflective plane size appeared to be a major determinant of this property. The same material showed different degrees of reflection depending on the surface profile. The size of grating lobes was affected by variation in the reflective plane size, but not by the intensity of reflection. The brightness of the grating lobes was similar among specimens.
Conclusions:
These results suggest that echo dropout and grating lobes can be effectively eliminated by an appropriate surface profile; thus, a likely practical solution would be to manufacture a surface that provides an adequate reflective surface size at various incident angles.
