Fifty-four consecutive CT scans have been used to construct a tomographic computational model of 14-year-old female torso suitable for the determination organ doses from CT. The model, known as ADELAIDE, is in form an input file compatible with user codes based on XYZDOS.MOR readily available EGS4 Monte Carlo radiation transport code. ADELAIDE's dimensions are close Australian averages her age so representative girl. realistic anatomy differs considerably that Cristy's 15-year-old...

A number of computer codes, developed using semi‐empirical models, are available to compute x‐ray spectra from a tungsten target for different tube parameters. In this study measured with high‐purity germanium detector compared those computed the empirical models and previously published data. The codes used generate based on proposed by Birch et al. Tucker agreed well model whereas produced “harder” spectrum spectra. Our spectral data Fewell

CT is a high-dose examination and possibly the dominant contributor to dose from diagnostic radiology. Estimates of organ doses are obtained Monte Carlo calculations used quantify radiation risk. To ensure validity using estimate actual dose, measurements must be compared with calculations. We have measured head chest dosimetry phantoms them (EGS4) calculated in voxel-based computational models phantoms. The simulation an x-ray spectrum specified values scanner's tube parameters....

The off‐axis x‐ray spectra from a constant potential generator were measured with high purity germanium spectrometer cooled to liquid nitrogen temperature. compared calculated using code based on the semiempirical model developed by Tucker et al. and Monte Carlo simulated EGS4 system. In this study, both model, system, found produce bremsstrahlung which agreed well at three emerging angles. generated total K ‐characteristic peaks in increasing order, as observed anode cathode direction,...

ABSTRACT A sample of undergraduate nursing students were allocated, according to their results in the first science exam, one three groups: "successful," "unsuccessful," and "middle." The was surveyed about perceived difficulty course reasons for difficulty. responses groups compared significant differences using KruskalWallis H statistic. successful group significantly different from unsuccessful a number questionnaire. Students perceive that is difficult, have low opinion ability science,...

Journal Article Monte Carlo Calculated Effective Dose to Teenage Girls from Computed Tomography Examinations Get access M. Caon, Caon Search for other works by this author on: Oxford Academic PubMed Google Scholar G. Bibbo, Bibbo J. Pattison Radiation Protection Dosimetry, Volume 90, Issue 4, 1 September 2000, Pages 445–448, https://doi.org/10.1093/oxfordjournals.rpd.a033172 Published: 01 2000

The study addresses the challenging problem of automatic segmentation human anatomy needed for radiation dose calculations.Three-dimensional extensions two well-known state-of-the art techniques are proposed and tested usefulness on a set clinical CT images.The new 3D Statistical Region Merging (3D-SRM) Efficient Graph-based Segmentation (3D-EGS). Segmentations eight representative tissues (lungs, stomach, liver, heart, kidneys, spleen, bones spinal cord)were accuracy using Dice index,...

Theoretical x‐ray spectra calculated by four different codes for the same tube parameters are compared calculating and measuring doses to computed tomography (CT) body head phantoms. The effect on 120 kV spectrum, hence dose, of varying anode angle, voltage, total filtration is investigated. Codes used were those Nowotny Höfer ( XCOMP ), Boone, Iles, Tucker et al. code based work produced noticeably lower than other best measured value. variation in dose between others order as introduced...

The paper studies the feasibility of using 3D extensions two state-of-the-art segmentation techniques, Statistical Region Merging (SRM) method and Efficient Graph-based Segmentation (EGS) technique, for automatic anatomy on clinical CT images.

AbstractNurses are routinely involved in the collecting and testing of urine plasma, dialysis, administration intravenous fluids treatment osmolar disorders, all which require an understanding solution concentration.This article discusses various ways concentration solutions stated, how they differ why different expressing useful human physiology. It also explains similarities differences between terms used to describe concentration: tonicity, percentage concentration, density, specific...

The paper introduces a novel model-guided method for liver segmentation in CT and PET-CT images. Using model volume as template shape annotated one of the patient slices, it automatically segments whole dataset. is based on non-deformable registration to data combination components pre-segmented by statistical region merging each slice maximise overlap with registered shape. It does not require construction probabilistic atlases, large training sets, or contrast enhancement portal venous...