[en] Exposure of the population to ionizing radiation for medical purposes is increasing throughout the world. In the United States of America, this exposure (3 mSv) has reached, even exceeded, exposure from natural sources. In France, the report of the French Institute for Radiological Protection and Nuclear Safety (IRSN) on exposure of the French population to ionizing radiation in 2007, based on the 74.6 million medical diagnostic procedures, estimates the mean individual effective dose to be 1.3 mSv. This value is much lower than the value in the United States but has progressed in 5 years by 62.5%. Computed tomography accounts for 10.1% of the procedures and 58% of the collective effective dose. This is why computed tomography is receiving very special attention from all those involved in radioprotection. It must be remembered, nevertheless, that we are well within the low dose range (effective dose less than 100 mSv), and indeed, in the large majority of CT examinations exposure values are lower than 15 mSv. The biological effects of low doses are still a matter of debate. First of all, it has not been possible to demonstrate the risk of cancer due to this level of exposure, neither on the survivors of the atomic bombs in Japan nor on workers in the nuclear industry in the United Kingdom. The year 2012 marked a change; for the first time, epidemiology took over from statistical studies. Despite the low risk demonstrated, reserves concerning methodology, and waiting for further European epidemiological studies underway, we must continue to act to encourage radiological protection. Before considering the action to take and without under-estimating the risks, it is important to remember that a computed tomography investigation is conducted in patients, and not in individuals in good health. Acting to provide patients with protection from radiation means involving all those concerned with justifying it, with substituting it, and with optimising it. For some years manufacturers have been developing technological innovations to reduce the dose, including control of automatic exposure, automatic selection of the most suitable voltage, appropriate filters, dynamic collimation in the Z-axis, iterative reconstruction, and techniques for reducing noise. Other innovations are underway focusing particularly on detector technology. The objective is to be able to undertake CT investigations with an effective dose lower than 1 mSv. If this objective is achieved in the next few years, progress will be considerable. We need to be able to renew our stock of scanners regularly so that our patients can reap the benefit. Clearly we are responsible each day for justifying the procedures. Substitution by non-irradiating procedures depends both on us and on the public authorities. Optimisation is also essential, and in the first instance will be achieved by abandoning the worship of a pretty picture. We have to set our minds on the objective of producing a diagnostic image with the lowest dose possible. It is the job of our profession to promote the spread of good practice guides and also encourage all teams to embark on optimising their protocols. In the end, we must all continue to keep ourselves informed and take part in assessing our practices

[en] We report a case of traumatic duodenal hematoma. The patient's age (2.5 y.) and the absence of evidence of trauma when the symptoms began led to perform plain films of the abdomen, upper GI series, US, CT and MR. This excess of imaging modalities emphasize the diagnostic value of plain X Rays of the abdomen and opacification of the duodenum. (authors)

No abstract available

[en] Gorham's disease usually manifests as diffuse osteolysis but may be complicated with pleural effusion. We describe the case of a 12 year old boy who had repeated pleural effusions. Radiographs show a mediastinal widening and an interstitial syndrome related to hemolymphangiomatous involvement. (authors)

[en] This case of mesenchymatous hamartoma in a wine-year-old boy, was an incidental finding on a chest X ray. CT and MRI suggested the diagnosis showing a large (9 x 11 x 14) mass developed in the right lower lung with sharp margins, without any sign of pulmonary or mediastinal compression. This lesion contained fatty areas on both CT and MRI. It showed no calcification. It enhanced slightly after IV contrast. On T2 WI, it appeared lobulated with low signal intensity septa. Presence of fatty tissues and lobulated margins were suggestive of the diagnosis of mesenchymatous hamartoma. A 1.2 kg mass was surgically removed. The tumor was attached to the right lower lobe by a small pedicle. Pathological examination disclosed fatty and connective tissues. This rare observation shows a good correlation between CT, MR, surgery and pathological examination. (author)

[en] Objectives: study of dosimetry impact of optimization actions in pediatrics CT scanning, after analysis and standardization of the practices in the service. results: A first analysis of six months of activity at the end of 2006 showed that the protocols, responding to the recommendations of the French society of pediatrics and prenatal imaging (S.F.I.P.P.) were poorly followed in the service: the practices were heterogeneous, and the average values of dose.(D.L.P.) length product were superior to the recommendations. At the end of 2007, an awareness action towards the personnel was realised and the protocols of acquisition established at the scanner implementation were modified. The analysis, at half 2008, following the pattern of 2006 showed a harmonization of practices in the service, a strong reduction of average value of the dose.length product (D.L.P.) by acquisition (50% in thorax CT scanning) and the systematic respect of the recommendations of the S.F.I.P.P.. conclusions: after evaluation of the service practices, the awareness of the personnel and the modification of protocols allowed to reduce strongly the doses delivered in paediatrics CT scanning (up to 50%, while keeping an image quality in accordance with the diagnosis. (N.C.)

[en] Since 2002 the ASN (French Nuclear Safety Authority) has been in charge of controlling radiation protection in all sectors. In the years 2007-2009 a series of incidents linked to the medical use of radiations has opened the way to a growing awareness of risks and the necessity of transparency in the medical sector. A situational analysis was made and a national plan was launched to get a better managing and control of the dose delivered to the patient and a reinforced sanitary follow-up of the staff. It is highlighted that radiation protection should evolve and be able to adapt to the new techniques used in radiotherapy or radio-diagnostic and that nuclear medicine uses generally low doses of radiation and radiation protection must reflect that. In the industrial sector some advances have been made concerning radiation protection: -) a reinforced control of mobile radiation sources, -) a more detailed list of radiation sources at the scale of the country, -) the implementation of more consistent regulations and work has begun to transpose into French law the European directive called Basic Safety Standards, -) a better assessment of the risks taken by operators, -) the managing of the end of life of radiation sources, and -) the protection against malevolent acts. (A.C.)

[en] The Department of radiology of the Hospital Trousseau (Paris) and I.R.S.N. have initiated in 2007 a detailed analysis of doses delivered to children undergoing CT examinations. This study involved three types of CT examination (chest, abdomen + pelvis and petrosal bones) and three age groups (new born to 1 year, 4 to 6 years and 9 to 11 years). A first analysis of doses was realised on a six months period of activity at the end of 2006. It stated that the standardized protocols of the scanner, that satisfied the relevant dosimetric requirements, were regularly modified by the operator to acquire the CT slides: the practice among the department was heterogeneous and the mean values of dose length product (D.L.P.) were systematically higher than those recommended. The whole staff of the department has been informed of these first results and made aware of optimization of delivered doses. The standardized protocols of the scanner have been optimized. A second analysis, similar to the first one, was conducted in 2008. It showed the harmonization of the practice among the department, a significant decrease in the mean D.L.P. (-50% for chest CT) and the respect for the dosimetric requirements for the three examinations concerned. (authors)

[en] We report one case of multilocular cyst of the kidney in one year and three months female infant who underwent echography, computed tomography and MRI before surgery. MR image accurately reflect the morphology of the tumor: the capsule is hypointense on T1-weighted images, the septa show moderate enhancement with intraveinous contrast. Varied intensities from fluid in the visualized locules presumably represent different concentration of proteins. MR imaging features are highly suggestive but non pathognomonic of the disease. Positive diagnosis always require histology. (authors). 7 refs., 7 figs

[en] Modern methods of immunofluorescence allow the detection of individual radio-sensitivity and it appears that radio-sensitivity can concern low radiation doses. Individual radio-sensitivity is all the more an important parameter to know as the statistics show that every people in France undergoes a radiological exam every 4 years and that the average radiation dose delivered in medical diagnostic is increasing. In order to contain the growth of medical doses, the principles of justification, limitation and optimization have to be applied. The ASN (French authority for nuclear safety) recommends more radiation physicists in hospitals and a complete overhaul of their training and the development of the MRI (Magnetic Resonance Imagery) fleet whose imagery scans can be an alternative to ionizing radiation exams. Patient irradiation is increasing as more imagery is necessary in modern medicine, for instance some cardiac surgery requires a visual control based on a ionizing radiation system. It also appears that the public is not always aware enough of the hazards of radiation when it undergoes medical exams. (A.C.)