Title :
Compensation for collimator divergence in SPECT using inverse Monte Carlo reconstruction
Author :
Floyd, C.E., Jr. ; Jaszczak, R.J. ; Manglos, S.H. ; Coleman, R.E.
Author_Institution :
Duke Univ. Med. Center, Durham, NC, USA
Abstract :
The inverse Monte Carlo (IMC) reconstruction algorithm achieved compensation for two degrading collimator effects in SPECT (single-photon-emission computed tomography) imaging: position dependence and radial/tangential asymmetry in reconstructed resolution. With filtered backprojection using a ramp filter, full width at half maximum (FWHM, radial and tangential, respectively) for a line source on axis with a high-sensitivity collimator were 19.3 mm and 16.4 mm. At 12 cm off axis, FWHM were 14.8 mm and 8.2 mm, respectively. With IMC after 35 iterations, FWHM on axis were 8.4 mm and 7.7 mm and off axis were 6.0 mm and 7.4 mm, respectively. Thus, for the simple imaging task of line sources with no background activity using simulated projection data, IMC provides compensation for the collimator effects in addition to providing higher resolution.<>
Keywords :
Monte Carlo methods; computerised tomography; radioisotope scanning and imaging; SPECT; collimator divergence; filtered backprojection; inverse Monte Carlo reconstruction; position dependence; radial/tangential asymmetry; ramp filter; single-photon-emission computed tomography; Cameras; Collimators; Degradation; High-resolution imaging; Image reconstruction; Image resolution; Monte Carlo methods; Optical imaging; Reconstruction algorithms; Spatial resolution;
Journal_Title :
Nuclear Science, IEEE Transactions on
