Paediatric x-ray radiation dose reduction and image quality analysis.

Collaboration of multiple staff groups has resulted in significant reduction in the risk of radiation-induced cancer from radiographic x-ray exposure during childhood. In this study at an acute NHS hospital trust, a preliminary audit identified initial exposure factors. These were compared with European and UK guidance, leading to the introduction of new factors that were in compliance with European guidance on x-ray tube potentials.

Estimation of organ and effective doses resulting from cone beam CT imaging for radiotherapy treatment planning.

In this study, organ doses were measured for various kilovoltage cone beam CT exposures on the Varian Acuity simulator and an alternative method of dose estimation was also assessed. Organ doses were measured by distributing thermoluminescent dosimeters (TLDs) throughout an anthropomorphic phantom, and effective doses were calculated using International Commission on Radiological Protection (ICRP) 60 and ICRP 103 tissue-weighting factors. The ImPACT CT patient dosimetry calculator was also used to estimate doses for comparison with the TLD results.

Effective doses to patients from CT acquisitions on the GE Infinia Hawkeye: a comparison of calculation methods.

Background: Nuclear medicine scans may be accompanied by CT acquisitions to provide localization of radioisotope uptake through image fusion and for use in attenuation correction. The effective doses to patients resulting from radioisotope administrations and from diagnostic CT scans are well documented. However, the development of gamma cameras with low dose CT attachments introduces the requirement for calculation of effective doses arising from non-standard CT acquisitions.

Comparison of the acoustic streaming in amniotic fluid and water in medical ultrasonic beams.

Aim: Acoustic streaming in amniotic fluid has been investigated under a variety of conditions relevant to the diagnostic use of ultrasound.

Method: An ultrasonic Doppler method has been used for measurement. Streaming velocities have been compared with those generated in water for the same exposure conditions.

Measurement of acoustic streaming using magnetic resonance.

Magnetic resonance imaging (MRI) has been used to explore acoustic streaming caused in water under ultrasonic exposure conditions similar to those used for diagnostic applications. Streaming was established in an enclosed tube with acoustically transparent end windows, using a pulsed, weakly-focused transducer of acoustic frequency 3.5 MHz.