@article{oai:repo.qst.go.jp:00043380,
 author = {Tomitani, Takehiro and Hirasawa, Masahiko and 富谷 武浩 and 平澤 雅彦},
 journal = {Physics in Medicine and Biology},
 month = {Jun},
 note = {The Compton camera is used for imaging the distributions of gamma-ray direction in
gamma-ray telescope for astrophysics and for imaging radioisotope distributions in
nuclear medicine without the need for collimators. The integration of gamma-rays
on a cone is measured with the camera, so that some sort of inversion method
is needed. Parra found an analytical inversion algorithm based on spherical
harmonics expansion of projection data. His algorithm is applicable to the full
set of projection data. In this paper, six possible reconstruction algorithms that
allow image reconstruction from projections with a finite range of scattering
angles are investigated. Four algorithms have instability problems and two
other are practical. However, the variance of the reconstructed image diverges
in these two cases, so that window functions are introduced with which the
variance becomes finite at a cost of spatial resolution. These two algorithms
are compared in terms of variance. The algorithm based on the inversion of the
summed back-projection is superior to the algorithm based on the inversion of
the summed projection.},
 pages = {2129--2146},
 title = {Image reconstruction from limited angle Compton camera deta},
 volume = {47},
 year = {2002}
}