AUTOMATED REGISTRATION OF VENTILATION-PERFUSION IMAGES WITH DIGITAL CHEST RADIOGRAPHS

Rationale and Objectives. The authors have developed an automated comp uterized technique for registering radionuclide lung scan images with digital chest radiographs. Methods. Threshold analysis was used to con struct contours around the high-activity regions of radionuclide venti lation-perfusion images. Analogous contours were constructed around th e lung regions of the corresponding digitized radiographs. Contour dim ensions and anatomic landmark locations were then used to superimpose the radiographic, ventilation, and perfusion images. Results. Evaluati on of 25 sets of images indicated that the scheme provided adequate to excellent registration in 91% of the pairwise combinations. Conclusio n. This automated scheme for registering ventilation-perfusion images with digital chest radiographs has the potential to aid radiologists i n the interpretation of these images.