To more easily estimate accurate values of collimator scatter facor, S(c), we suggest a two-component saturation model that accounts for scatter from the primary collimator and flattening filter and from the collimator jaws. This model, which assumes an exponential distribution of scatter intensity, was tested by in-air measurements using a mini-phantom for 4 MV and 10 MV X-rays of a Clinac 210...

This study proposes a method to accurately estimate the phantom scatter factor (Sp) of arbitrary rectangular fields. We measured output doses in water and air; these measured values were based on square fields and a limited number of symmetric rectangular fields using 4 MV and 10 MV X-rays of a Varian Clinac-iX. We calculated Sp from these measured values. Then, using these Sp values, we estima...

PURPOSE Hepatocyte growth factor/scatter factor (HGF/SF) possesses mitogenic, motogenic, and morphogenic properties and has recently been implicated in various retinal diseases. The role of HGF/SF in proliferative vitreoretinal disease was investigated. METHODS Sections of epiretinal membranes were stained immunohistochemically for cytokeratins, to identify HRPE cells, and for HGF/SF receptor...

UNLABELLED (201)Tl-Chloride ((201)Tl) is a myocardial perfusion SPECT agent with excellent biochemical properties commonly used for assessing tissue viability. However, cardiac (201)Tl SPECT images are severely degraded by photons scattered in the thorax. Accurate correction for this scatter is complicated by the nonuniform density and varied sizes of thoraxes, by the additional attenuation and...