1. A method for calculating a volume of a cardiac chamber from a plurality of slices of image data, comprising: a processor receiving a plurality of short axis images and a plurality of long axis images of the cardiac chamber; the processor determining a base plane from a landmark in a long axis image of the cardiac chamber; the processor determining an intersection between the base plane and the short axis images; the processor determining a contour in a first slice of the cardiac chamber in a short axis image determined by a segmentation of the chamber and the intersection; the processor calculating a volume related to the contour in the first slice, which is a first partial contribution to the volume of the cardiac chamber; and the processor calculating a volume related to a contour in a second slice of the cardiac chamber in a short axis image determined by a segmentation of the cardiac chamber which does not intersect with the base plane.