Visualisation of 4-D colour and Power doppler data

Abstract

Mechanically scanned, cardiac-gated, 4-D colour Doppler and power Doppler data were acquired and rendered using multiplanar slice display, surface-fitting (S-F) and direct volume rendering (DVR), with interactive viewpoint control or tool command language (Tcl)-scripted generation of animation sequences across the cardiac cycle. S-F applied the marching cubes algorithm within a YCbCr colour space to extract time-varying Doppler regions; supplementally generated surfaces enclosed all regions across the full cardiac cycle, partially to alleviate the problem of incomplete vessel filling. DVR used integrated intensity, maximum intensity and front-to-back projection; the latter applied an opacity function to the Cb, Cr and Y colour channels to control the appearance of the blood flow signal relative to the background B-mode image. Our most detailed display was a hybrid approach that combined multiplanar slicing and DVR. (E-mail: Teresa.Robinson@ubht.swest.nhs.uk)