Construction and validation of an infant chest phantom for paediatric computed tomography.

Paediatric imaging protocols should be carefully optimised to maintain the desired image quality while minimising the delivered patient dose. A paediatric chest phantom was designed, constructed and evaluated to optimise chest CT examinations for infants. The phantom was designed to enable dosimetry and image quality measurements within the anthropomorphic structure. It was constructed using tissue equivalent materials to mimic thoracic structures of infants, aged 0-6 months. The phantom materials were validated across a range of diagnostic tube voltages with resulting CT numbers found equivalent to paediatric tissues observed via a survey of clinical paediatric chest studies. The phantom has been successfully used to measure radiation dose and evaluate various image quality parameters for paediatric specific protocols.

Establishment of a local diagnostic reference level for dental intraoral bitewing X-rays.

A state-based local diagnostic reference level (LDRL) for dental intraoral X-rays has been established. LDRL values of 2.0 mGy incident air kerma (IAK) and 57 mGy•cm2 air kerma-area product (KAP) for an adult posterior bitewing X-ray were determined based on 811 X-ray units surveyed. This IAK LDRL value is greater than those established in several other nations and regions around the world in similar studies. Analyses of radiographic technique and equipment usage are included to provide broad guidance as to ways that imaging could be optimised, such as in the selection of exposure factors, collimators, image receptors, and X-ray unit models.

Mammography diagnostic reference levels in Western Australia.

Mammography dose data has been collected from Western Australian units to establish Diagnostic Reference Levels for the state. Reference levels have been determined for a variety of phantom thicknesses for both full field digital mammography units and digital breast tomosynthesis units. Levels for the American College of Radiology (ACR) Phantom have been established as 1.3 mGy and 1.5 mGy mean glandular dose for full field digital mammography and digital breast tomosynthesis respectively. 2 cm PMMA was 0.9 mGy and 1.0 mGy and 6 cm PMMA had values of 2.0 mGy and 2.3 mGy. This data can be utilised to help establish national reference levels in the future.