Abstract
Simultaneous acquisition of dual-isotope SPECT data offers a number of advantages over separately acquired data; however, simultaneous acquisition can result in cross-contamination between isotopes. In this work we propose and evaluate two frameworks for iterative model-based compensation of cross- contamination in dual-isotope SPECT. The methods were applied to cardiac imaging with technetium-99m-sestamibi and thallium-201, and they were compared with a subtraction-based compensation method using a cross-talk estimate obtained from an auxiliary energy window. Monte Carlo simulations were performed to carefully study aspects of bias and noise for the methods, and a torso phantom with cardiac insert was used to evaluate the performance of the methods for experimentally acquired data. The cross-talk compensation methods substantially improved lesion contrast and significantly reduced quantitative errors for simultaneously acquired data. Thallium image normalized mean square error (NMSE) was reduced from 0.522 without cross- talk compensation to as low as 0.052 with model-based cross-talk compensation. This is compared with a NMSE of 0.091 for the subtraction- based compensation method. The application of a preliminary model for cross- talk arising from lead fluorescence x-rays and collimator scatter gave promising results, and the future development of a more accurate model for collimator interactions would probably benefit simultaneous Tc/Tl imaging. Model-based compensation methods provide feasible cross-talk compensation in clinically acceptable times, and they may ultimately make simultaneous dual- isotope protocols an effective alternative for many imaging procedures.
Original language | English (US) |
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Pages (from-to) | 1843-1860 |
Number of pages | 18 |
Journal | Physics in medicine and biology |
Volume | 44 |
Issue number | 7 |
DOIs | |
State | Published - Jul 1999 |
Externally published | Yes |
ASJC Scopus subject areas
- Radiological and Ultrasound Technology
- Radiology Nuclear Medicine and imaging