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Développement d'une stratégie pour optimiser les doses délivrées en CT pédiatrique

English title Development of a strategy to optimise radiation dose in paediatric CT
Applicant Verdun Francis
Number 105951
Funding scheme Project funding (Div. I-III)
Research institution Institut de Radiophysique Département de Radiologie Université de Lausanne/CHUV
Institution of higher education University of Lausanne - LA
Main discipline Paediatrics
Start/End 01.01.2005 - 30.06.2007
Approved amount 169'775.00
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All Disciplines (2)


Keywords (6)

paediatric radiology; computed tomography (CT); image quality; radiation exposure optimisation; observer performance; signal detection

Lay Summary (English)

Lay summary
The irradiation of children due to CT examinations is becoming a sensitive issue, as shown by a particularly alarming paper published newspapers. There are several reasons for this: CT examinations belong to the most irradiating radiological procedures and deliver more than one third of the collective dose in adults while only accounting for 5% of the total radiological examinations performed. Due to the technological developments, CT examinations performed in children, who are 3 to 10 times more sensitive to ionising radiations than adults, are increasing rapidly from an estimated frequency of 4% in 1998 to 11% today. This evolution has not been yet associated with a systematic analysis of the link between patient dose and image quality. As for all radiological techniques using ionising radiations, CT image noise, which impairs the detection of low contrast lesions, decreases with the increase of patient dose. Although various approaches have been taken by different groups to reduce the exposure of children in rather unacceptable situations, the maximum amount of image noise (i.e. the lowest level of patient dose), which can be accepted by radiologists, has not been fully addressed. In spite of this lack of knowledge, manufacturers are introducing different ways to control the amount of noise present in the image. The main purpose of this project is to address this problematic situation by studying the effect of the amount of quantum noise present in images (i.e. source of image noise directly linked with patient dose) on the detection of low contrast lesions present in different anatomical regions. The initial approach to this objective will be a survey involving 10 centres, responsible for an estimated 85% of the total CT examinations performed on children in Switzerland. This survey will enable us not only to assess the current practices in term of examination methodology, but will also offer a platform to validate the acquisition protocols established during this project. At the end of the project we shall answer to the following questions: What are, for the most common CT examinations, the variations in dose and image quality applied to the paediatric population in Switzerland? What are, for the most common low contrast lesions found in CT examinations, the relationships between the amount of quantum noise present in images and the detection rate when dealing with homogeneous backgrounds? What is the influence of the anatomy of the patient (anatomical background) on lesion detection and up to what level quantum noise can be increased without impairing the detection of critical lesions?
Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants


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136785 Le suivi de jeunes patients d'oncologie par des examens de radiodiagnostic: une évaluation du risque radiologique en vue d'une optimisation des partiques 01.06.2012 DORE project funding
120382 Dose en CT cardiaque chez l'enfants et les jeunes adultes: un optimum entre qualité d'image et dose de radiations 01.12.2008 Project funding (Div. I-III)
120382 Dose en CT cardiaque chez l'enfants et les jeunes adultes: un optimum entre qualité d'image et dose de radiations 01.12.2008 Project funding (Div. I-III)
124814 Automatisation des enquêtes sur l'exposition de la population par la radiologie médicale: étude pilote. 01.04.2009 DORE project funding
67826 Potential advantages of phase contrast in X-ray diagnostic imaging 01.01.2003 Project funding (Div. I-III)