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...

background: in myocardial perfusion spect imaging, images are degraded by photon attenuation, the distance-dependent collimator, detector response and photons scatter. filters greatly affect quality of nuclear medicine images materials and methods: a phantom simulating heart left ventricle was built. about 1mci of 99mtc was injected into the phantom. images were taken from this phantom. some fi...

a 16-year-old class ii female patient was treated without tooth extraction. the upper first molars were distalized by the pendulum appliance. after six months, the molars tipped significantly to the distal. to correct this side effect, we decided to upright the molars using skeletal anchorage. on each side, a mini-screw was inserted between first and second premolars in the buccal cortical plat...

introduction quality control is an important phenomenon in nuclear medicine imaging. a jaszczak spect phantom provides consistent performance information for any spect or pet system. this article describes the simulation of a jaszczak phantom and creating an executable phantom file for comparing assessment of spect cameras using simind monte carlo simulation program which is well-established fo...

As a trilogy, this first paper along with the authors' two companion articles introduces alternate approaches to standard $R$-matrix parametrization of nuclear cross sections. The authors present evidence so-called shadow poles in theory for ${}^{134}$Xe. number and location depends upon how one continues operators complex wave numbers. also establish new pole sections, called $w\phantom{\rule{...

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