Automatic Detection of Air Holes Inside the Esophagus in CT Images

Air holes inside the esophagus can be used to localize the esophagus in computed tomographic (CT) images. In this work we present a technique to automatically detect esophageal air holes in this modality. Our technique is based on the extraction of a volume of interest, air segmentation by thresholding and classification of respiratory and esophageal air using a priori knowledge about the connectivity of air voxels. A post-processing step rejects wrong results from artifacts in the CT image. We successfully tested our algorithm with clinical data and compared the detection results of a human expert and our technique.