Evaluation of lesion detectability and crosstalk correction methods in dual radionuclide imaging
- Columbia Univ., NY (United States)
- Brookhaven National Lab., Upton, NY (United States)
Crosstalk components (XC) present in one or both energy windows (EWs) in dual radionuclide images can influence the detectability of cold defects and overestimate areas of hyperperfusion. Changes in lesion contrast due to the presence of crosstalk photons and correction methods were evaluated for combinations of radionuclides. Monte Carlo simulations of SPECT and planar imaging of a brain phantom containing 10 lesions ranging in size from 1 to 12 cm{sup 2} were run for Tc-99m, Xe-133, Tl-201 and I-123. Simulations of the gray and white matter compartments and lesions were run individually to allow greater flexibility in evaluating different radionuclide uptake distributions. Simulations of image acquisition at 15 EWs, corresponding to the baseline settings and EWs commonly used for imaging all four radionuclides, were recorded for each radionuclide. The system energy resolution (ER) was set at 1% intervals between 6 and 14%. XCs were calculated for: (1) Tc and I with 4:1 activity ratio (AR) of Tc/I; (2) Tc and Tl with a 5:1 AR and (3) Tc and Xe with a 2:1 and 4:1 AR. Cold defects of 10 to 60% with Xe, Tl and I were seen as 3 to 45% defects due to XC from Tc when similar distribution and defect size were assumed for both radionuclides. Large changes in lesion contrast were observed when multiple lesions with increased (hyperperfused regions) and decreased activity were used in the same study especially if cold lesions on Xe, Tl and I images, appear as regions with increased activity uptake on the Tc study. Image contrast improved when images recorded in the 100-110 keV EW were used to estimate and correct for Tc XC in the Xe- and Tl-studies; 10-60% defects were seen as defect of 6-55%. The study shows that large changes in lesion contrast and detectability due to XC can be corrected using a third EW in dual radionuclide imaging of Tc-Xe and Tc-Tl.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States)
- DOE Contract Number:
- AC02-76CH00016
- OSTI ID:
- 197927
- Report Number(s):
- CONF-940605-; ISSN 0161-5505; TRN: 95:007029-0062
- Journal Information:
- Journal of Nuclear Medicine, Vol. 35, Issue Suppl.5; Conference: 41. annual meeting of the Society of Nuclear Medicine, Orlando, FL (United States), 5-8 Jun 1994; Other Information: PBD: May 1994
- Country of Publication:
- United States
- Language:
- English
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