Method for recognizing multiple radiation fields in computed radiography

ABSTRACT An algorithm is developed to detect collimation regions in computed radiography images. Based on a priori knowledge of the collimation process, the algorithm consists of four major stages of operations: (1) pixel-level detection and classification of collimation boundary transition pixels; (2) line-level delineation of candidate collimation blades; (3) estimation of the most likely partitioning; and (4) region-level determination of the collimation configuration. Thisalgorithm has been tested on a set of 8,436 images, which includes 7,703 single-exposure images and 733 multiple- exposure images. An overall success rate in excess of 99% has been achieved. Keywords: digital computerized radiography, multiple radiation field recognition, collimation detection 1. INTRODUCTION Computed radiography (CR) is a medical imaging technique that captures the information using storage phosphorscreens. Multiple-exposure is a common practice for CR in the radiology departments, because certain body parts