Virtual reality in 3D echocardiography: dynamic visualization of atrioventricular annuli surface models and volume...

Knowledge about annuli shape and blood flow patterns, both optimally assessed by transesophageal 3D Doppler echocardiography, can be used in computer assisted surgical planning of heart valve reconstruction. Moreover, information about the individual shape of the annulus anatomy can guide the design of annular prostheses. The problem is that the annulus cannot be easily differentiated from the valve and the myocardium with standard visualization methods. We have developed a nearly automatic method for annulus segmentation. The algorithm provides the annulus shape in a symbolic description, which can be used for surface visualization. Best results to visualize the blood flow from the Doppler signal and the myocardial morphology are obtained by volume rendering. A hybrid visualization technique combining surface rendering and volume rendering enables to dynamically visualize the surface rendered annulus combined with a volume rendered 3D (plus time) reconstruction of either backscatter (morphology) and Doppler information (in original color coding), or together with backscatter only or Doppler only. Visualization of annuli structures combined with blood flow and general myocardial morphology provides a new tool to analyze heart diseases.