Hilde M. Olerud

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The objective of the present work was to determine current levels and recent nationwide trends in radiological examination frequency, as well as to update corresponding collective effective dose estimates. Examination frequencies were obtained from radiology management systems at all hospitals and private radiology enterprises across Norway in terms of(More)
The increasing worldwide use of paediatric computed tomography (CT) has led to increasing concerns regarding the subsequent effects of exposure to radiation. In response to this concern, the international EPI-CT project was developed to study the risk of cancer in a large multi-country cohort. In radiation epidemiology, accurate estimates of organ-specific(More)
The aim of this study was to test the applicability of the guidance levels for patient doses cooperatively set by the radiation protection authorities in the five Nordic countries. The kerma-area product (KAP) for five conventional radiological examination types was obtained from several hospitals in each of the Nordic countries. The number of radiographic(More)
The aim of this study was to compare mean glandular dose (MGD) in all full-field digital mammography (FFDM) and screen film mammography (SFM) systems used in a national mammography screening program. MGD from 31 screening units (7 FFDM and 24 SFM), based on an average of 50 women at each screening unit, representing 12 X-ray models (6 FFDM and 6 SFM) from(More)
Children with shunt-treated hydrocephalus are still followed routinely with frequent head CT scans. To estimate the effective dose, brain and lens doses from these examinations during childhood, and to assess dose variation per examination. All children born between 1983 and 1995 and treated for hydrocephalus between 1983 and 2002 were included. We(More)
In computer tomography (CT) diagnostics, the measured Hounsfield units (HU) are used to characterize tissue and are in that respect compared to nominal HU values found in the radiological literature. Quality assurance (QA) phantoms are commercially available with a variety of tissue substitutes and materials to test the HU values in CT. It is however(More)
The purpose of the study was to develop a methodology that allowed quantitative assessment of image quality in CT and its relationship to dose. An anthropomorphic phantom was designed for use in receiver operating characteristic (ROC) studies of the detectability of liver lesions with CT. The lesions were simulated by different mixtures of glycerol and(More)
BACKGROUND The main aim of mammographic screening is to reduce the mortality from breast cancer. However, use of ionizing radiation is considered a potential harm due to the possible risk of inducing cancer in healthy women. PURPOSE To estimate the potential number of radiation-induced breast cancers, radiation-induced breast cancer deaths, and lives(More)
Computed tomography (CT) has great clinical utility and its usage has increased dramatically over the years. Concerns have been raised, however, about health impacts of ionising radiation exposure from CTs, particularly in children, who have a higher risk for some radiation induced diseases. Direct estimation of the health impact of these exposures is(More)
To assess the range of doses in paediatric CT scans conducted in the 1990s in Norway as input to an international epidemiology study: the EPI-CT study, http://epi-ct.iarc.fr/ . National Cancer Institute dosimetry system for Computed Tomography (NCICT) program based on pre-calculated organ dose conversion coefficients was used to convert CT Dose Index to(More)