NREC designed and implemented a medical image
registration system to accurately estimate a patient’s
position for therapy.
For radiotherapy and other forms of therapy to be
successful, patients must be correctly positioned for treatment. The
medical image registration system uses two-dimensional X-rays
and three-dimensional CT scans to accurately estimate the
position and orientation of a patient’s anatomy with
respect to an external coordinate frame.
High-speed computer graphics algorithms render simulated
X-rays from CT scan data in a fraction of a second. These
high-resolution, simulated radiographs are compared with
actual X-ray images using a novel image comparison algorithm. The
comparison algorithm ignores noise in the images and clutter
from the patient's other anatomy to correctly estimate
the patient's position.
The system achieved sub-millimeter registration accuracies
in preliminary tests, with total registration times on
the order of 50 seconds. Tests using clinical patient data