Murine vs human tissue compositions: implications of using human tissue compositions for photon energy absorption in mice.

Methods:: Dual energy CT (DECT) images of 9 female mice were used to extract the effective atomic number Z and the relative electron density ρ for each voxel in the images. To investigate the influence of the tissue compositions on the absorbed radiation dose for a typical kilovoltage photon beam, mass energy-absorption coefficients μ/ρ were calculated for 10 different tissues in each mouse.

Results: Differences between human and murine tissue compositions can lead to errors around 7.

Automatic multiatlas based organ at risk segmentation in mice.

Objective:: During the treatment planning of a preclinical small animal irradiation, which has time limitations for reasons of animal wellbeing and workflow efficiency, the time consuming organ at risk (OAR) delineation is performed manually. This work aimed to develop, demonstrate, and quantitatively evaluate an automated contouring method for six OARs in a preclinical irritation treatment workflow.

Methods:: Microcone beam CT images of nine healthy mice were contoured with an in-house developed multiatlas-based image segmentation (MABIS) algorithm for six OARs: kidneys, eyes, heart, and brain.

The EPTN consensus-based atlas for CT- and MR-based contouring in neuro-oncology.

Purpose: To create a digital, online atlas for organs at risk (OAR) delineation in neuro-oncology based on high-quality computed tomography (CT) and magnetic resonance (MR) imaging.

Methods: CT and 3 Tesla (3T) MR images (slice thickness 1 mm with intravenous contrast agent) were obtained from the same patient and subsequently fused. In addition, a 7T MR without intravenous contrast agent was obtained from a healthy volunteer.