Method and system for automatic detection of ribs and pneumothorax in digital chest radiographs

摘要

A method and system for the detection of anatomical features in a digital chest radiograph, and in particular rib edges and pneumothorax, wherein vertical profiles are defined in regions of the lungs in the radiograph, and a model function is fitted to the profiles to obtain initial estimates of the locations of rib edges. Gradient-histogram analysis is performed by determining edge gradient and their corresponding orientations in regions of interest (ROIs) defined in the radiograph in the vicinity of the initially estimated rib edges, determining the maximum edge gradient in each of the ROIs, and forming histograms which define accurate detections of rib edges. The edges are fitted with an elliptical function and a representation of the entire rib cage structure is obtained. The method and system are also applied to the detection of pneumothorax where ROIs are defined in the apical lung region and edge gradients and their orientations are detected in the ROIs. The ROI is edge-enhanced using the edge gradients and their orientations and previously detected rib edges are removed. Subtle, curved-line structure corresponding to pneumothorax in the edge-enhanced ROI are detected and a representation of the pneumothorax is obtained using a Hough transform.