DocumentCode :
438627
Title :
Maximum-likelihood expectation-maximization algorithm for improved clinical SPECT scintimammography
Author :
Krol, Andrzej ; Feiglin, David H. ; Lee, Wei ; Kunniyur, Vikram R. ; Gangal, Kedar R. ; Coman, Ioana L. ; Lipson, Edward D. ; Karczewski, Deborah A. ; Thomas, F. Deaver
Author_Institution :
Dept. of Radiol., SUNY Upstate Med. Univ., Syracuse, NY, USA
Volume :
6
fYear :
2004
fDate :
16-22 Oct. 2004
Firstpage :
3523
Abstract :
Conventional MLEM and OSEM algorithms used in SPECT Tc-99m sestamibi scintimammography produce hot spot artifacts (HSA). We investigated a suitable modification of MLEM and OSEM algorithms needed to reduce HSA. Patients with suspicious breast lesions were administered 10 mCi of Tc-99m sestamibi and SPECT scans with patients in prone position with uncompressed breasts were acquired. In addition, to simulate breast lesions, some patients were imaged with a number of breast skin markers each containing 1 μCi of Tc-99m. We modified MLEM and OSEM algorithms by removing from the backprojection step the rays that traverse the periphery of the support region on the way to a detector bin when their path length trough this region is shorter than some preset critical length. Such very short paths result in a very low projection counts contributed to the detector bin and this in turn gives rise to a overestimation of the activity in the peripheral voxels in the backprojection step, thus creating HSA. We analyzed the breast-lesion contrast and suppression of HSA in the images reconstructed using conventional and modified MLEM and OSEM algorithms vs. critical path length (CPL). For CPL≥0.01 pixel size, we observed improved breast-lesion contrast and lower noise in the images reconstructed, and a very significant reduction of HSA in the maximum intensity projection (MIP) images.
Keywords :
cancer; image reconstruction; mammography; maximum likelihood estimation; medical image processing; optimisation; single photon emission computed tomography; technetium; tumours; Tc-99m sestamibi scintimammography; backprojection; breast lesion; breast skin markers; clinical SPECT scintimammography; critical path length; detector bin; hot spot artifacts; image reconstruction; maximum intensity projection images; maximum-likelihood expectation-maximization algorithm; ordered subsets expectation maximization algorithm; Algorithm design and analysis; Breast; Detectors; Expectation-maximization algorithms; Image analysis; Image reconstruction; Lesions; Maximum likelihood detection; Pixel; Skin;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Nuclear Science Symposium Conference Record, 2004 IEEE
ISSN :
1082-3654
Print_ISBN :
0-7803-8700-7
Electronic_ISBN :
1082-3654
Type :
conf
DOI :
10.1109/NSSMIC.2004.1466646
Filename :
1466646
Link To Document :
بازگشت