Contour extraction in multi-phase, multi-slice cardiac MRI studies by propagation of seed contours between images

摘要

Contours are extracted from corresponding features the left ventricular blood pool-endocardium interfaces, of a plurality of images collected as a multi-phase multi-slice cardiac Magnetic Resonance Imaging (MRI) study which are accessible by a computer in response to user input to the computer of a seed contour identifying the contour feature to be extracted in an initial image at a middle slice position and a predetermined phase position, namely end of diastole. From this as the only contour inputted by the user, contours are extracted from each image by a sequence of automatic propagation of determinations of extracted, or final contours by forming from a final contour for an image, a seed contour for a not yet processed image which immediately adjoins in slice or phase position. For each image use is made of a seed-to-final propagation function in the form of an energy minimizing active contour function which has internal energy due to settable resistances to stretching and bending and image derived energy related to the gradient of the image. The final contour developed in the initial image is passed as a provisional contour to images which immediately adjoin in phase position where they are further propagated by an in-phase provisional-to- seed propagation function and are passed to images which immediately adjoin in slice position, where they are further propagated by an in- slice provisional-to-seed propagation function. After extraction of the contours, and possible automatic post-processing for correction thereof, these contours are used by a computational or visualization application, such as the computation of an ejection fraction.