From digital image processing of colour Doppler M-mode maps to noninvasive evaluation of the left ventricular...

Noninvasive estimation of diastolic pressure gradients has recently been validated using the space-temporal velocity distribution available from colour Doppler M-mode (CDM). However, the methods currently applied for analysing CDM patterns of left ventricular (LV) filling have limitations, such as lack of automation, subjective variability and limited use of digital velocity map. For this reason, we have developed software able to acquire and process the CDM maps; thus, providing an easily interpretable graphical and numerical display. The pressure field is obtained by approximating the derivatives with centred finite differences via the incompressible Navier-Stokes equations. After digital filtering of the noise and the removal of the colour black spots, the velocity field is utilised to compute the pressure gradient field and the pressure values by spatial integration. It is concluded that automatic quantification of colour CDM patterns is feasible and will be a strategic tool in the investigation of one of the most intriguing topics in cardiology.