Mass attenuation coefficients and partial photon interactions have been calculated theoretically at incident photon energy 1 Kev to 100 GeV for garnet series of gemstones (Grosaularite (GS1), Pyrope(GS2), Spessarlite(GS3), Almandine(GS4), Uvarovite(GS5) and Androdite(GS6) using XCOM software [1]. The values of these parameters have been found to change significantly with incident photon energy ...

Quantitation in cardiac positron emission tomography (PET) and single-photon emission computed tomography (SPECT) depends on being able to correct for several physical factors that tend to distort the data. One of the most important of these corrections is the correction for attenuation. For PET, cardiac attenuation correction is a reality, although certain problems remain to be solved. For SPE...

Quantitative information on photon scattering around brachytherapy sources is needed to develop dose calculation formalisms capable of predicting dosimetric parameters with minimal empiricism. Photon absorption and scatter around brachytherapy sources can be characterized using the tissue attenuation factor, defined as the ratio of dose in water to water kerma in free space. In this study, the ...

Background: In Radiation Therapy, the sparing of normal tissues can be performed using either multi-leaf collimators or Cerrobend blocks. The current work focuses on the physical characteristics of Cerrobend blocks including attenuation coefficient, effective penumbra width and isodose curves undulation in penumbral regions. Materials and Methods: All measurements were performed using ...

Physical factors such as photon attenuation degrade image quality and quantitative accuracy in single-photon emission computed tomography (SPECT). It is often considered (especially in situations with non-uniform attenuation and distance-dependent spatial resolution (DDSR)) that adequate compensation for the effects of these physical factors requires data acquired over 2 . However, as the analy...

background: in radiation therapy, the sparing of normal tissues can be performed using either multi-leaf collimators or cerrobend blocks. the current work focuses on the physical characteristics of cerrobend blocks including attenuation coefficient, effective penumbra width and isodose curves undulation in penumbral regions. materials and methods: all measurements were performed using a dual en...

OBJECTIVE X-ray attenuation coefficients are used in common radiological, pathological and spectroscopic examinations and in the determination of the radiation dose distribution in biological tissues. In radiology, these coefficients enable diagnosis by differentiating the abnormal tissues from the normal ones using their morphological structure and contrast differences. In this study, our aim ...

Introduction: Photon attenuation in tissues is the primary physical degrading factor limiting both visual qualitative interpretation and quantitative analysis capabilities of reconstructed Single Photon Emission Computed Tomography (SPECT) images. The aim of present study was to investigate the effect of attenuation correction on the detection of activation foci following statistical analysis w...