Title :
Simultaneous dual-isotope SPECT with a single CdZnTe detector
Author :
Barber, William C. ; Hasegawa, Bruce H. ; Shah, Kanai S.
Author_Institution :
California Univ., San Francisco, CA, USA
Abstract :
Summary form only given. Regional myocardial perfusion in patients with ischemic heart disease can be assessed with sequential rest/stress radionuclide imaging of 99mTc-sestamibi and 201Tl. However patient comfort, patient through-put, and registration of the rest and stress images could be improved if the dual-isotope SPECT images were acquired simultaneously rather than sequentially. In simultaneous acquisitions, the 201Tl image can be contaminated by down-scatter from 99mTc and by K fluorescence when photons from 99mTc and 201Tl interact in the lead collimator. These errors may be reduced by recording the dual-isotope data using a detector with improved energy resolution. We therefore have evaluated the performance of a SPECT system using a CdZnTe detector for simultaneous 99mTc and 201Tl imaging. A comparison between resolution phantom images reconstructed from data with different sized energy windows for 201Tl could determine if improved detector energy resolution can reduce or eliminate the need for cross-talk correction. The SPECT projection data, taken with various 201Tl energy windows, are convolved with a Ramachandran-Lakshminarayan kernel and backprojected to reconstruct a 256×256 pixel tomographic image. Results indicate improved 201Tl images with a 20% window compared to a 30% window at 70 keV. The FWHM energy resolution of the CdZnTe detector is 5% at 140 keV and 8% at 70 keV. Development of a dual-isotope SPECT camera with increased energy resolution compared to current clinical systems can reduce the errors introduced in the 201Tl image when simultaneous 201Tl/99mTc data are acquired.
Keywords :
cardiovascular system; diseases; gamma-ray detection; haemorheology; image reconstruction; image registration; image resolution; medical image processing; phantoms; semiconductor counters; single photon emission computed tomography; 140 keV; 256 pixel; 65536 pixel; 70 keV; Ramachandran-Lakshminarayan kernel; fluorescence; image reconstruction; image registration; image resolution; improved energy resolution; ischemic heart disease; patient comfort; patient through-put; phantom images; regional myocardial perfusion; sequential rest/stress radionuclide imaging; simultaneous dual-isotope SPECT; single CdZnTe detector; CD recording; Cardiac disease; Detectors; Energy resolution; Fluorescence; Image reconstruction; Myocardium; Optical collimators; Single photon emission computed tomography; Stress;
Conference_Titel :
Nuclear Science Symposium Conference Record, 2003 IEEE
Print_ISBN :
0-7803-8257-9
DOI :
10.1109/NSSMIC.2003.1352303