Development of a mouse computational model for MCNPx based on Digimouse (r) images and dosimetric assays

Abstract

The aim of this study was to create and test a new mice 3D-voxel phantom named DM_BRA for mice and human first-estimation radiopharmaceutical dosimetry. Previously, the article reviews the state-ofart in animal model development. Images from Digimouse CT database were used in the segmentation and on the generation of the voxelized phantom. Simulations for validation of the DM_BRA model was performed at 0.015, 0.1, 0.5, 1 and 4 MeV photons with heart-source. Specific Absorbed Fractions (SAF) data were compared with literature data. The organ masses of DM_BRA correlated well with existing models based on the same dataset; however, few small organ masses hold significant variations. The SAF data in most simulated cases were statistically equal to a significant level of 0.01 to the reference data.Uniterms: Dosimetry/assay. Mouse phantom/tests. MCNPx Monte Carlo code Computational studies.

Whole body potassium as a biomarker for potassium uptake using a mouse model

“…The concentration was slightly higher than 2000 ppm reported in ICRP23 and 2080 ppm in the human soft tissue reported by Christy et al 30,31 . It is customary in the literature to use the same elemental composition for the mice, as reported for the reference man (ICRP89 & ICRP23) 32 . We compared our results with an absolute concentration of potassium found in mice in the literature for neutron-activation: H. C. Bigginand et al reported 0.24% average potassium concentration in mice compared with an average of 0.26% (average% by weight) computed in our experiment 26 .…”

Validation study of voxel phantom monte carlo simulations with EGSnrc C++ class library

“…The MC simulations were performed on a computer with eight Intel® Core™ i7 of 3.40 GHz and 8 GB RAM. Internal and external photon sources were considered and three voxel phantoms with different levels of complexity were taking into account: DM_BRA mouse phantom [15], Golem anthropomorphic phantom [16], and case 5 XCAT model phantom from AAPM TG 195 report [1]. The results were validated using the relative percentage difference (Δ%) as follows: Δ% = 100% (q-q 0 ) (q 0 ) -1 (1) where q are the results calculated in this work and q 0 are the results taken as reference.…”

“…Many structures were segmented from these data such as brain, heart, lungs, liver, stomach, spleen, pancreas, kidneys, bladder, skeleton and skin. The binary image (8 bits unassigned) of the DM_BRA is 152 x 396 x 42 and the voxels dimensions are 0.25 mm x 0.25 mm x 0.50 mm representing a 28 g male nude mouse [15]. 23 organs/tissues were segmented and their chemical compositions and densities were based on human data, present in ICRP Publication 110 [18].…”

“…The SAF of a given radiation energy is the ratio between the fraction of the radiation emitted by the source region that is absorbed in the target region and the mass of the target region, in kg -1 . For the validation, SAF values calculated by Mendes et al [15] using MCNPx Monte Carlo code were considered as reference values. Since the masses of tissues/organs are necessary for SAF calculations, they were also compared.…”

“…The heart was considered the source and five different monoenergetic photons were simulated. The results from Mendes et al [15] using MCNPx are also shown and are taken as reference values. The adrenals were the only tissue that presented different organ mass in comparison with Mendes et al [15].…”