The reduction in Monte Carlo calculated organ doses from CT with tube current modulation using WILLIAM, a voxel model of seven year-old anatomy.

The construction of a voxel model of seven year-old male anatomy from a low resolution whole body CT scan acquired with a PET-CT scanner is described. The model is referred to as WILLIAM. The model was used to compare the Monte Carlo calculated relative organ doses with and without tube current modulation from simulated CAP and chest CT examinations.

The ratio of ICRP103 to ICRP60 calculated effective doses from CT: Monte Carlo calculations with the ADELAIDE voxel paediatric model and comparisons with published values.

The ADELAIDE voxel model of paediatric anatomy was used with the EGSnrc Monte Carlo code to compare effective dose from computed tomography (CT) calculated with both the ICRP103 and ICRP60 definitions which are different in their tissue weighting factors and in the included tissues. The new tissue weighting factors resulted in a lower effective dose for pelvis CT (than if calculated using ICRP60 tissue weighting factors), by 6.5% but higher effective doses for all other examinations.

Osmoles, osmolality and osmotic pressure: clarifying the puzzle of solution concentration.

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

Radiation information and informed consent for clinical trials.

Examples of the statements about the radiation from medical imaging in the information for participants provided to the Human Research Ethics Committee (HREC) for approval are presented and discussed. There is considerable scope for improvement in the information about radiation that is presented to potential participants in clinical trials. Many radiation statements seem only intended to allay fear and anxiety about radiation rather than providing accurate information.

Voxel-based computational models of real human anatomy: a review.

Computational models of human anatomy are mathematical representations of human anatomy designed to be used in dosimetry calculations. They have been used in dosimetry calculations for radiography, radiotherapy, nuclear medicine, radiation protection and to investigate the effects of low frequency electromagnetic fields. Tomographic medical imaging techniques have allowed the construction of digital three-dimensional computational models based on the actual anatomy of individual humans.