@inproceedings{oai:repo.qst.go.jp:00053321,
 author = {Tomitani, Takehiro and Hirasawa, Masahiko and 富谷 武浩 and 平澤 雅彦},
 book = {IEEE Nuclear Science Symposium Conference Record : Nuclear Science Symposium, Medical Imaging Conference},
 month = {May},
 note = {Since the integration of gamma-rays on a cone is
measured with Compton cameras, some sort of image reconstruction
method is necessary. Parra developed an analytical reconstruction
algorithm based on a spherical-harmonics expansion
of projection data that covers the entire scattering-angle range.
The scattering-angle range is limited due to the electrical noise of
the detector and due to the finite detector configuration. In this
article, a reconstruction algorithm from the projection of a limited
scattering-angle range is presented. The algorithm is based on an
inversion of the summed back-projection. The variance of the
reconstructed image of a uniform source was analyzed and is proportional
to the third power of the number of expansion terms.
Thus, window functions are introduced to suppress noise at the
cost of spatial resolution. The dependency of the spatial resolution
on the number of expansion terms was analyzed. The dependency
of the variance on the spatial resolution was found to be that variance
is proportional to (spatial resolution)^(-1/3).},
 title = {Analytical image reconstruction of cone-beam projections from limited angle Compton camera data},
 volume = {2002},
 year = {2003}
}