By Topic

Evaluation of Monte Carlo-based compensation for scatter and crosstalk in simultaneous In-111/Tc-99m SPECT-CT imaging of infection

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

2 Author(s)
Cervo, M. ; Dept. of Radiol., Brigham & Women''s Hosp., Boston, MA, USA ; Moore, S.C.

Osteomyelitis (OM), a bone-marrow infection, is best diagnosed by simultaneous In-111 white blood cell and Tc-99m sulfur colloid imaging. The diagnosis has conventionally been based on a visual assessment of images, where a region of increased In-111 activity, spatially concordant with a region of decreased Tc-99m activity, indicates possible OM. To obtain more accurate and precise tomographic images of both radionuclides, we modified a previously developed Monte Carlo (MC)-based scatter and crosstalk estimation procedure based on a joint ordered-subsets expectation-maximization (MC-JOSEM) reconstruction algorithm, and compared its performance to that of a triple-energy-window-based (TEW-OSEM) reconstruction approach. A numerical phantom with eight simulated bone-marrow infection regions was used to evaluate the performance of both methods in simultaneous In-111/Tc-99m imaging. After using our SPECT MC program to simulate essentially noise-free data for both tracers, eight independent projections of Poisson-noise deviates were generated. Volumes of interest (VOI) were drawn in five normal-marrow and eight infected-marrow locations to assess the performance of both methods, with respect to that achievable using primary photons only from both nuclides. Overall, MC-JOSEM (χ2=1.7) outperformed TEW-OSEM (χ2=7.4). After one iteration, which provided the lowest mean-squared error of activity estimates, the average relative bias ± precision of reconstructed Tc-99m activity concentration in regions of infection decreased from 81.6±17.7% for images not compensated for scatter (NC) to 11.1±12.3% (MC) vs. 16.9±11.0% (TEW) and, in normal-bone regions, decreased from 34.4±22.5% (NC) to -3.9±10.8% (MC) vs. 4.1±11.5% (TEW). For In-111, the relative accuracy ± precision in regions of infection improved from 11.6±14.1% (NC) to 0.6±9.9 % (MC) vs. 15.5±8.5% (TE- ) and, in normal-bone regions, decreased from 75.8±31.2% (NC) to 34.8±26.4% (MC) vs. 60.6±21.2% (TEW).

Published in:

Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC), 2011 IEEE

Date of Conference:

23-29 Oct. 2011