9 research outputs found

    Radiography of scoliosis Comparative dose levels and image quality between a dynamic flat-panel detector and a slot-scanning device (EOS system)

    Get PDF
    International audienceTo compare radiation dose and image quality between a slot-scanning system (SSS) and a dynamic flat-panel detector (DFD) in assessing scoliosis in children. An experimental study was first performed with a phantom to assess the quality of each device. The clinical part included a prospective observational dosimetric and qualitative comparative study with acquisition of whole-spine X-ray SSS (31 children), DFD (26 children). Institutional review board approval and informed consent were obtained. Dosimetric statistical analysis was performed from dose area product (DAP) and entrance skin dose measured by thermo-luminescent dosimeters localized in the cervical, thoracic and sacral areas. Assessment of the diagnostic quality (phantom and clinical) was realized by independent evaluation by 3 observers, using statistical analysis of quality score and inter-observer reproducibility. DAP was equivalent with the 2 systems. Entrance skin dose was significantly higher with DFD in thoracic and pelvic regions (P<0.05). Image quality scores of the SSS were significantly better than DFD for a majority of criteria, in both phantom and clinical evaluations. For scoliosis evaluation, the SSS, compared to the DFD system, offers enhanced image quality while reducing the entrance skin dose in the most radiosensitive areas. © 2015 Éditions françaises de radiologie

    Eye lens irradiation by CT perfusion: dosimetry and optimization

    No full text
    International audienc

    Establishment of diagnostic reference levels in cardiac ct in france A need for patient dose optimisation

    No full text
    International audienceThe objective of this study was to propose diagnostic reference levels (DRLs) for coronary computed tomography angiography (CCTA), in the context of a large variability in patient radiation dose, and the lack of European recommendations. Volume Computed Tomography Dose Index (CTDIvol) and dose-length product (DLP) were collected from 460 CCTAs performed over a 3-month period at eight French hospitals. CCTAs (50 per centre) were performed using the routine protocols of the centres, and 64- to 320-detector CT scanners. ECG gating was prospective (n = 199) or retrospective (n = 261). The large gap in dose between these two modes required to propose specific DRLs 26 and 44 mGy for CTDIvol, and 370 and 970 mGy cm for DLP, respectively. This study confirms the large variability in patient doses during CCTA and underlines the need for the optimisation of cardiac acquisition protocols. Availability of national DRLs should be mandatory in this setting. © The Author 2014

    Pleural plaques and asbestosis: Dose- and time-response relationships based on HRCT data

    No full text
    Most studies on asbestos-related diseases are based on chest radiographs, and dose-response relationships are still controversial. The aim of this study was to describe the most relevant parameters of asbestos exposure linked to pleural plaques and asbestosis diagnosed by high-resolution computed tomography (HRCT). A large screening programme including systematic HRCT examinations was organised from 2003 to 2005 in France for formerly asbestos-exposed workers. The time since first exposure (TSFE), level, duration and cumulative exposure to asbestos were used in adjusted unconditional logistic regression to model the relationships of the two diseases. Analysis of a population of 5,545 subjects demonstrated that TSFE (p<0.0001) and cumulative exposure (p=0.02) (or level, depending on the models used), were independently associated with the frequency of pleural plaques. Only cumulative exposure (p<0.0001) or level of exposure (p=0.02) were significantly associated with asbestosis. All trend tests were significant for these parameters. To date and to our knowledge, this study is the largest programme based on HRCT for the screening of asbestos-exposed subjects. Both time-response and dose-response relationships were demonstrated for pleural plaques, while only dose-response relationships were demonstrated for asbestosis. These parameters must be included in the definition of high-risk populations for HRCT-based screening programmes. Copyright©ERS Journals Ltd 2009
    corecore