Movement Detection System for Pet Scanners

Period of Performance: 09/15/1987 - 03/14/1988


Phase 1 SBIR

Recipient Firm

Cti, Inc.
Knoxville, TN 37922
Principal Investigator


During a PET scan, the movement of the subject of more than a mm will cause noticeable blurring of the image. Movement will also cause artifacts to be introduced into the image because the matrix for correcting for gamma-ray absorption is determined for a specific position. This proposal outlines the development of a movement detection system using a small array of ultrasonic transducers that train narrow beams of ultrasound on selected areas on the subject in the image volume. The movement of the subject from the initial position will be detected by measuring the change in transit time of the sound reflected back to the transducers. If motion exceeding the preset acceptable amount occurs, the system will automatically stop data acquisition and display the displacements for each transducer so that the operator can move the subject back into position before resuming data acquisition. This movement detection system will allow more efficient use of the expensive PET systems, insure better imaging, and help eliminate repeat injection of the subject with radioactive isotopes.