3D ultrasonography is a much talked thing now, but the equipment involved are is costly. Is there any software available which can convert 2D usg images to 3D?
do you mean convert 2D ultrasound imaging into 3D ultrasound volume image?
One of the approach is freehand ultrasound. A 3D position sensor is rigidly attached on the 2D ultrasound probe. Then the 2D images can be reconstructed into a volumetric images. A calibration is usually needed to estimate the transformation between the 2D image and the reconstructed volume coordinate.
You will need some kind of registration in Space of Your 2D Slices, either optically, acoustically, mechanic or magnetic. Having the coordinates in Space, there are several Methods and SWs to make 3D images, but the easiest is to apply Your own vendors SW.