Online 3-D Reconstruction of the Right Atrium From Echocardiography Data via a Topographic Cellular Contour Extraction Algorithm

A computational method providing online, automated 3-D reconstruction of the right atrium of the human heart is presented in this paper. Endocardial boundaries were extracted from transesophageal ultrasound data by a topographic cellular contour extraction (TCCE) algorithm. The TCCE method was implemented on a continuous-time, analog, massively parallel processor, and on a digital serial processor. Processing speeds were $\hbox{500}$ or $\hbox{40}$ frames per second, depending on the hardware used. Extracted boundary point sets were rendered into a 3-D mesh and the volume of the cavity was quantified. Accuracy of volume quantification was validated on 60 in vitro static phantoms and 12 clinical subjects. For the clinical recordings, reference volumes were estimated from manually delineated endocardial boundaries. The average error of volume quantification by the TCCE method was $\hbox{8\%} \pm \hbox{5\%}$ ($n$ = 12), the average of the interobserver variability between two independent human experts was $\hbox{5\%} \pm \hbox{2\%}$ ($n$ = 6). Interactive planning of atrial septal defect closure in pediatric cardiology is presented as an example that demonstrates a potential clinical application of the method.