Search results for "Effective atomic number"
showing 3 items of 3 documents
Efficacy of single-source rapid kV-switching dual-energy CT for characterization of non-uric acid renal stones: a prospective ex vivo study using ant…
2019
Purpose To investigate the accuracy of rapid kV-switching single-source dual-energy computed tomography (rsDECT) for prediction of classes of non-uric-acid stones. Materials and methods Non-uric-acid renal stones retrieved via percutaneous nephrolithotomy were prospectively collected between January 2017 and February 2018 in a single institution. Only stones >= 5 mm and with pure composition (i.e., >= 80% composed of one component) were included. Stone composition was determined using Fourier Transform Infrared Spectroscopy. The stones were scanned in 32-cm-wide anthropomorphic whole-body phantom using rsDECT. The effective atomic number (Zeff), the attenuation at 40 keV (HU40), 70 ke…
209 New Fricke gel with high sensitivity and low diffusion for 3D-MRI dosimetry
2018
Purpose Fricke gel (FG) dosimeters are good candidates for 3D dose assessment in biological materials. Their effective atomic number and density are similar to those of soft tissue. In view of their chemical and morphological characteristics, FG serve as dosimeters and as phantoms at the same time. FG dosimeters are obtained by incorporating an acidic aqueous solution of ferrous ions Fe2+ into a gel matrix. In order to address the limitations of gels based on natural matrices, we have studied FG produced with a matrix of poly-vinyl alcohol (PVA) cross-linked with glutaraldehyde (GTA). Materials and methods The proposed gel contains 10% w/v of PVA and GTA of 1%w/v. A common formulation agaro…
ESR response to 60Co-rays of ammonium tartrate pellets using as additive
2007
Abstract This work presents experimental results regarding a new ammonium tartrate blend for ESR dosimetry, with a higher sensitivity and a lower lowest detectable dose (LDD) to Co 60 γ -rays than the recently used pure ammonium tartrate. The blend composed by ammonium tartrate and gadolinium-oxide ( Gd 2 O 3 ) shows a greater sensitivity ( ∼ 2 times) and a smaller LDD than ammonium tartrate. The increased sensitivity was mainly attributed to the great atomic number ( Z = 64 ) of gadolinium, that increases the effective atomic number of the blend; the interaction probability with photons and consequently the radical yield is therefore enhanced. Moreover ammonium tartrate with Gd 2 O 3 has a…