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A review of patient doses from CT examinations in the UK for 2003 has been conducted on the basis of data received from over a quarter of all UK scanners, of which 37% had multislice capability. Questionnaires were employed to collect scan details both for the standard protocols established at each scanner for 12 common types of CT examination on adults and(More)
The complex conditions of irradiation in computed tomography (CT), involving highly-collimated X-ray beams, necessitate the use of specially-defined dose descriptors such as the computed tomography dose index (CTDI). When used in a weighted form (CTDIW), this concept can describe the absorbed dose from a single slice in standard head and body phantoms. The(More)
A new UK computed tomography (CT) survey has provided a useful snapshot of patient doses for 2003. Scan details for nearly 850 standard protocols and 2,000 individual patients relating to 12 common CT examinations on adults and children were collected by questionnaires voluntarily submitted by a widely-distributed sample of 126 scanners. This represented(More)
The mean energy imparted to the patient has been proposed as a practical quantity which may be useful for assessing somatic risk in X-ray diagnostic radiology. A technique is described for estimating energy imparted during most common X-ray examinations of the trunk or complete head from a measurement of exposure-area product conveniently provided by the(More)
This report presents the results of a study of frequency and collective dose for medical and dental X-ray examinations in the UK in 2008. The frequency data were collected from the radiology information systems (RIS) at a sample of 29 NHS Trusts in England. The total number of medical and dental X-ray examinations carried out in the UK, both inside and(More)
What challenge? CT has developed dramatically: scanning is faster, images are better, applications have grown and, of course, radiation doses have come down, have they not? Well, no, actually; quite the contrary in fact. When CT was new it was appreciated that it was a relatively high dose technique but there was overriding clinical justification for using(More)
Monte Carlo simulations of CT examinations have been performed to estimate effective doses, normalized to axial air kerma, for six mathematical phantoms representing ages from newborn to adult, and for three CT scanner models covering a range of designs. Organ doses were calculated for CT exposures of contiguous, 1 cm wide, transverse slices in each phantom(More)
Estimating the dose delivered to the patient in X-ray computed tomography (CT) examinations is not a trivial task. Monte Carlo (MC) methods appear to be the method of choice to assess the 3D dose distribution. The purpose of this work was to extend an existing MC-based tool to account for arbitrary scanners and scan protocols such as multi-slice CT (MSCT)(More)
Surveys in the U.K. have identified the patterns of patient exposure from diagnostic medical radiological procedures and have led to the development of structured advice to promote optimisation of patient protection, including diagnostic reference levels for some common conventional X-ray examinations. Trends for reductions in individual patient and(More)