TY - JOUR
T1 - Application of distance-dependent resolution compensation and post- reconstruction filtering for myocardial SPECT
AU - Hutton, Brian F.
AU - Lau, Yiu H.
PY - 1998
Y1 - 1998
N2 - Compensation for distance-dependent resolution can be directly incorporated in maximum likelihood reconstruction. Our objective was to examine the effectiveness of this compensation using either the standard expectation maximization (EM) algorithm or an accelerated algorithm based on use of ordered subsets (OSEM). We also investigated the application of post- reconstruction filtering in combination with resolution compensation. Using the MCAT phantom, projections were simulated for 360°data, including attenuation and distance-dependent resolution. Projection data were reconstructed using conventional EM and OSEM with subset size 2 and 4, with/without 3D compensation for detector response (CDR). Also post- reconstruction filtering (PRF) was performed using a 3D Butterworth filter of order 5 with various cutoff frequencies (0.2-1.2 cycles cm-1). Image quality and reconstruction accuracy were improved when CDR was included. Image noise was lower with CDR for a given iteration number. PRF with cutoff frequency greater than 0.6 cycles cm-1 improved noise with no reduction in recovery coefficient for myocardium but the effect was less when CDR was incorporated in the reconstruction. CDR alone provided better results than use of PRF without CDR. Results suggest that using CDR without PRF, and stopping at a small number of iterations, may provide sufficiently good results for myocardial SPECT. Similar behaviour was demonstrated for OSEM.
AB - Compensation for distance-dependent resolution can be directly incorporated in maximum likelihood reconstruction. Our objective was to examine the effectiveness of this compensation using either the standard expectation maximization (EM) algorithm or an accelerated algorithm based on use of ordered subsets (OSEM). We also investigated the application of post- reconstruction filtering in combination with resolution compensation. Using the MCAT phantom, projections were simulated for 360°data, including attenuation and distance-dependent resolution. Projection data were reconstructed using conventional EM and OSEM with subset size 2 and 4, with/without 3D compensation for detector response (CDR). Also post- reconstruction filtering (PRF) was performed using a 3D Butterworth filter of order 5 with various cutoff frequencies (0.2-1.2 cycles cm-1). Image quality and reconstruction accuracy were improved when CDR was included. Image noise was lower with CDR for a given iteration number. PRF with cutoff frequency greater than 0.6 cycles cm-1 improved noise with no reduction in recovery coefficient for myocardium but the effect was less when CDR was incorporated in the reconstruction. CDR alone provided better results than use of PRF without CDR. Results suggest that using CDR without PRF, and stopping at a small number of iterations, may provide sufficiently good results for myocardial SPECT. Similar behaviour was demonstrated for OSEM.
UR - http://www.scopus.com/inward/record.url?scp=0031807137&partnerID=8YFLogxK
U2 - 10.1088/0031-9155/43/6/022
DO - 10.1088/0031-9155/43/6/022
M3 - Article
C2 - 9651033
AN - SCOPUS:0031807137
SN - 0031-9155
VL - 43
SP - 1679
EP - 1693
JO - Physics in Medicine and Biology
JF - Physics in Medicine and Biology
IS - 6
ER -