These tests will reveal if the algorithm can be used as a second reader for automatic comparison of current and previous mammograms. The rate of uptake of the contrast agent is used to characterize a given lesion. This rate is studied by observing the change in grey level of the lesion at several instants of time after injection of the agent. However, the loose and non-rigid nature of breast tissue almost guarantees that these different images would be misregistered. To study the uptake process effectively and to also make a quantitative estimate of change in uptake, it would be necessary to align or register these different images.
Image registration is thus an important problem.
A new algorithm, based on transforming the given 3D MRI images to texture maps for automatic control point extraction and registration, is currently being developed. It will be tested initially on a set of 18 patients, imaged at the Department of Radiology, University of Iowa. It is hoped that the preliminary results obtained using these 18 patients will help to validate the algorithm. Further testing will be performed on a larger data set.