Object and detector scatter-function dependence on energy and position in high resolution PET

The authors have shown in previous works that distinct non-stationary analytical scatter kernels can be extracted from line source measurements and used to independently subtract object scatter and subtract or restore detector scatter in high resolution PET. In this work, the dependence of the scatter components on energy threshold and source position was investigated. Line source measurements were acquired in multispectral mode using the Sherbrooke PET simulator. Scatter parameters were extracted from data summed in energy windows with a lower threshold varying from 129 keV to 516 keV in steps of 42 keV, and a fixed upper threshold of 644 keV. Decreasing the lower threshold from 344 keV to 129 keV increases the trues by only 25%, but increases object scatter by 136% and almost triples detector scatter. A gain in efficiency by a factor of 2 or more would result from recovering the latter by restoration in the broad window. The intensity and shape of the scatter functions for both object and detector are shown to have a significant dependence on energy and position. This dependence needs to be taken into account in the design of kernels for accurate scatter correction over a broad energy range. >

[1]  Roger Lecomte,et al.  A PET camera simulator with multispectral data acquisition capabilities , 1992 .

[2]  Christopher J. Thompson,et al.  Two new strategies to increase the signal to noise ratio in positron volume imaging , 1993 .

[3]  R Lecomte,et al.  Assessment of scatter components in high-resolution PET: correction by nonstationary convolution subtraction. , 1995, Journal of nuclear medicine : official publication, Society of Nuclear Medicine.

[4]  S. Grootoonk,et al.  Correction for scatter using a dual energy window technique with a tomograph operated without septa , 1991, Conference Record of the 1991 IEEE Nuclear Science Symposium and Medical Imaging Conference.

[5]  Joel S. Karp,et al.  Triple energy window scatter correction technique in PET , 1992, IEEE Conference on Nuclear Science Symposium and Medical Imaging.

[6]  Roger Lecomte,et al.  Tuning of avalanche photodiode PET camera , 1992 .

[7]  R. Lecomte,et al.  Potentials of multispectral acquisition in positron emission tomography , 1992, IEEE Conference on Nuclear Science Symposium and Medical Imaging.

[8]  Joel S. Karp,et al.  Special Papers Section-NPSS/Medical Imaging Conference Cross-Plane Scattering Correction-Point Source Deconvolution in PET , 1991 .

[9]  R. Trebossen,et al.  A PET scatter correction using simultaneous acquisitions with low and high lower energy thresholds , 1993, 1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference.

[10]  Roger Lecomte,et al.  Normalization of multispectral data in positron emission tomography , 1993 .

[11]  R.L. Harrison,et al.  Dual energy window scatter corrections for positron emission tomography , 1991, Conference Record of the 1991 IEEE Nuclear Science Symposium and Medical Imaging Conference.

[12]  C. Bohm,et al.  Correction for Scattered Radiation in a Ring Detector Positron Camera by Integral Transformation of the Projections , 1983, Journal of computer assisted tomography.

[13]  S R Meikle,et al.  A convolution-subtraction scatter correction method for 3D PET. , 1994, Physics in medicine and biology.

[14]  W. W. Moses,et al.  A positron tomograph with 600 BGO crystals and 2.6 mm resolution , 1988 .

[15]  Roger Lecomte,et al.  Energy dependence of scatter components in multispectral PET imaging , 1995, IEEE Trans. Medical Imaging.

[16]  Roger Lecomte,et al.  Design and engineering aspects of a high resolution positron tomograph for small animal imaging , 1994 .

[17]  Sibylle Ziegler,et al.  Scatter correction in the transaxial slices of a whole-body positron emission tomograph , 1993 .