VERFAHREN UND VORRICHTUNG ZUR AUTOMATISCHEN, MIT COMPUTERN DURCHGEFUEHRTEN ANALYSE DER HERZ- UND LUNGENGROESSEN IN DIGITALEN BRUSTRADIOGRAPHIEN

摘要

An automated method and system to determine a number of parameters related to the size and shape of the heart as well as parameters related to the lungs from data derived from digital chest radiographs. A cardiac rectangle enclosing the heart and portions of the surrounding lung tissue is determined, and within the cardiac rectangle, horizontal and vertical profiles, and the first derivatives thereof, are determined. Based on these derivatives, cardiac boundary points on the left and right sides of the cardiac contour are determined, as well as diaphragm edge points. A predetermined model function is then fitted to selected of the determined cardiac boundary points to determine the cardiac contour. Tests are performed to determine whether or not the heart has an abnormal size or is a "tall" heart, and if so, corrective measures are taken. In a preferred embodiment, a shift-variant cosine function is used as a model function fitted to the selected cardiac boundary points. In an alternative embodiment, the model function is equivalent to the partial summation of a Fourier series. In an alternative embodiment for determining cardiac boundaries, an analysis is made of edge gradients obtained in two orthogonal directions in plural narrow band regions of the data from the digital chest radiograph.