Lesion Removal Program
Perception research based on actual examinations of patients has always been difficult because of the limited control over the presence and absence of abnormalities within the images. The only way to simulate abnormalities has been to image objects to resemble lesions within the same devices used for patients, and then combine patient and object images photographically or digitally. Such simulated abnormalities have been limited to pulmonary nodules and liver lesions on radiographic images and computed tomography CT scans. Perception research on more diverse abnormalities and imaging modalities has had to rely on “found” imaging studies that often include undesired abnormal areas that complicate scoring and distract observers. Compiling images for meaningful target and control studies is often the most time consuming component of the research. The seamless removal of these abnormal areas would make a substantially larger portion of medical images available for research.
We have embarked on a project to provide editing and manipulation tools to greatly expand the range of images available for perception studies including those in which computers serve as observers. These tools will significantly increase the amount of productive research that can be done in diagnostic imaging. To date we have created interactive data language IDL programs to remove pulmonary nodules in tomographic images, store the abnormalities in libraries after removing backgrounds, and replace the abnormalities in normal tomographic images. We have used four-alternative forced-choice with known-location paradigms as well as free-search tasks to study whether the alterations are detectible in the easiest tasks and tasks closer to clinical interpretation.
On this web site we are providing example IDL programs to accomplish the tasks described above along with sample image sets and limited documentation. The programs should run easily in a WIndows IDL environment and can be adapted with minimal effort for MacIntosh or Unix systems. Currently, we can only provide very limited support for software that is posted, but we hope to expand the support in the future.