Title :
Real-time system for respiratory-cardiac gating in positron tomography
Author :
Klein, G.J. ; Reutter, B.W. ; Ho, M.H. ; Reed, J.H. ; Huesman, R.H.
Author_Institution :
Center for Functional Imaging, Lawrence Berkeley Lab., CA, USA
Abstract :
A Macintosh-based signal processing system has been developed to support simultaneous respiratory and cardiac gating on the ECAT EXACT HR PET scanner. Using the Lab-View real-time software environment, the system reads analog inputs from a pneumatic respiratory bellows and an ECG monitor to compute an appropriate histogram memory location for the PET data. Respiratory state is determined by the bellows signal amplitude; cardiac state is based on the time since the last R-wave. These two states are used in a 2D lookup table to determine a combined respiratory-cardiac state. A 4-bit address encoding the selected histogram is directed from the system to the ECAT scanner, which dynamically switches the destination of tomograph events as respiratory-cardiac state changes. To test the switching efficiency of the combined Macintosh/ECAT system. A rotating emission phantom was built. Acquisitions with 25 msec gates while the phantom was rotating at 240 rpm demonstrate the system could effectively stop motion at this rate, with approximately 5 msec switching time between gates
Keywords :
Apple computers; cardiology; electrocardiography; medical image processing; pneumodynamics; positron emission tomography; real-time systems; 25 ms; 2D lookup table; 4-bit address; 5 ms; ECAT EXACT HR PET scanner; ECG monitor; Lab-View real-time software environment; Macintosh-based signal processing system; R-wave; analog inputs; histogram memory location; medical diagnostic imaging; nuclear medicine; pneumatic respiratory bellows; positron tomography; real-time system; respiratory state; respiratory-cardiac gating; rotating emission phantom; switching efficiency; Analog computers; Bellows; Electrocardiography; Histograms; Imaging phantoms; Monitoring; Positron emission tomography; Real time systems; Signal processing; Software systems;
Conference_Titel :
Nuclear Science Symposium, 1997. IEEE
Conference_Location :
Albuquerque, NM
Print_ISBN :
0-7803-4258-5
DOI :
10.1109/NSSMIC.1997.670546