The Experts below are selected from a list of 183 Experts worldwide ranked by ideXlab platform

A R Cowen - One of the best experts on this subject based on the ideXlab platform.

  • A comprehensive physical image quality evaluation of a selenium based digital x‐ray imaging system for Thorax Radiography
    Medical Physics, 1998
    Co-Authors: J H Launders, S M Kengyelics, A R Cowen
    Abstract:

    A selenium based digital x-ray system dedicated to chest Radiography has been installed by the UK Department of Health’s Medical Devices Agency at Leeds General Infirmary, UK, to undergo a comprehensive evaluation, including the physical image quality. The underlying characteristics which define the overall image quality of a system are the following: sensitometric response, modulation transfer function, and noise power spectrum. These have been measured objectively on preprocessed digital data acquired under relevant radiographic conditions. The image data is further processed prior to hard copy display. The displayed image quality may only be measured subjectively; threshold contrast detail detectability is such a measure which can be related to the objective measures of image quality. The objective imagingcharacteristics suggest that Thoravision has a significant advantage over conventional Radiographyimaging systems. However, subjective measures have demonstrated that the image processing can have a significant effect on the perceived image quality. Thoravision has the potential to deliver a significantly improved image quality to clinicians with no increase in radiation exposure to the patient, or image quality may be maintained with a reduction in radiation exposure. Digital image processing is central to the efficiency with which it achieves this.

  • a comprehensive physical image quality evaluation of a selenium based digital x ray imaging system for Thorax Radiography
    Medical Physics, 1998
    Co-Authors: J H Launders, S M Kengyelics, A R Cowen
    Abstract:

    A selenium based digital x-ray system dedicated to chest Radiography has been installed by the UK Department of Health’s Medical Devices Agency at Leeds General Infirmary, UK, to undergo a comprehensive evaluation, including the physical image quality. The underlying characteristics which define the overall image quality of a system are the following: sensitometric response, modulation transfer function, and noise power spectrum. These have been measured objectively on preprocessed digital data acquired under relevant radiographic conditions. The image data is further processed prior to hard copy display. The displayed image quality may only be measured subjectively; threshold contrast detail detectability is such a measure which can be related to the objective measures of image quality. The objective imagingcharacteristics suggest that Thoravision has a significant advantage over conventional Radiographyimaging systems. However, subjective measures have demonstrated that the image processing can have a significant effect on the perceived image quality. Thoravision has the potential to deliver a significantly improved image quality to clinicians with no increase in radiation exposure to the patient, or image quality may be maintained with a reduction in radiation exposure. Digital image processing is central to the efficiency with which it achieves this.

J H Launders - One of the best experts on this subject based on the ideXlab platform.

  • A comprehensive physical image quality evaluation of a selenium based digital x‐ray imaging system for Thorax Radiography
    Medical Physics, 1998
    Co-Authors: J H Launders, S M Kengyelics, A R Cowen
    Abstract:

    A selenium based digital x-ray system dedicated to chest Radiography has been installed by the UK Department of Health’s Medical Devices Agency at Leeds General Infirmary, UK, to undergo a comprehensive evaluation, including the physical image quality. The underlying characteristics which define the overall image quality of a system are the following: sensitometric response, modulation transfer function, and noise power spectrum. These have been measured objectively on preprocessed digital data acquired under relevant radiographic conditions. The image data is further processed prior to hard copy display. The displayed image quality may only be measured subjectively; threshold contrast detail detectability is such a measure which can be related to the objective measures of image quality. The objective imagingcharacteristics suggest that Thoravision has a significant advantage over conventional Radiographyimaging systems. However, subjective measures have demonstrated that the image processing can have a significant effect on the perceived image quality. Thoravision has the potential to deliver a significantly improved image quality to clinicians with no increase in radiation exposure to the patient, or image quality may be maintained with a reduction in radiation exposure. Digital image processing is central to the efficiency with which it achieves this.

  • a comprehensive physical image quality evaluation of a selenium based digital x ray imaging system for Thorax Radiography
    Medical Physics, 1998
    Co-Authors: J H Launders, S M Kengyelics, A R Cowen
    Abstract:

    A selenium based digital x-ray system dedicated to chest Radiography has been installed by the UK Department of Health’s Medical Devices Agency at Leeds General Infirmary, UK, to undergo a comprehensive evaluation, including the physical image quality. The underlying characteristics which define the overall image quality of a system are the following: sensitometric response, modulation transfer function, and noise power spectrum. These have been measured objectively on preprocessed digital data acquired under relevant radiographic conditions. The image data is further processed prior to hard copy display. The displayed image quality may only be measured subjectively; threshold contrast detail detectability is such a measure which can be related to the objective measures of image quality. The objective imagingcharacteristics suggest that Thoravision has a significant advantage over conventional Radiographyimaging systems. However, subjective measures have demonstrated that the image processing can have a significant effect on the perceived image quality. Thoravision has the potential to deliver a significantly improved image quality to clinicians with no increase in radiation exposure to the patient, or image quality may be maintained with a reduction in radiation exposure. Digital image processing is central to the efficiency with which it achieves this.

S M Kengyelics - One of the best experts on this subject based on the ideXlab platform.

  • A comprehensive physical image quality evaluation of a selenium based digital x‐ray imaging system for Thorax Radiography
    Medical Physics, 1998
    Co-Authors: J H Launders, S M Kengyelics, A R Cowen
    Abstract:

    A selenium based digital x-ray system dedicated to chest Radiography has been installed by the UK Department of Health’s Medical Devices Agency at Leeds General Infirmary, UK, to undergo a comprehensive evaluation, including the physical image quality. The underlying characteristics which define the overall image quality of a system are the following: sensitometric response, modulation transfer function, and noise power spectrum. These have been measured objectively on preprocessed digital data acquired under relevant radiographic conditions. The image data is further processed prior to hard copy display. The displayed image quality may only be measured subjectively; threshold contrast detail detectability is such a measure which can be related to the objective measures of image quality. The objective imagingcharacteristics suggest that Thoravision has a significant advantage over conventional Radiographyimaging systems. However, subjective measures have demonstrated that the image processing can have a significant effect on the perceived image quality. Thoravision has the potential to deliver a significantly improved image quality to clinicians with no increase in radiation exposure to the patient, or image quality may be maintained with a reduction in radiation exposure. Digital image processing is central to the efficiency with which it achieves this.

  • a comprehensive physical image quality evaluation of a selenium based digital x ray imaging system for Thorax Radiography
    Medical Physics, 1998
    Co-Authors: J H Launders, S M Kengyelics, A R Cowen
    Abstract:

    A selenium based digital x-ray system dedicated to chest Radiography has been installed by the UK Department of Health’s Medical Devices Agency at Leeds General Infirmary, UK, to undergo a comprehensive evaluation, including the physical image quality. The underlying characteristics which define the overall image quality of a system are the following: sensitometric response, modulation transfer function, and noise power spectrum. These have been measured objectively on preprocessed digital data acquired under relevant radiographic conditions. The image data is further processed prior to hard copy display. The displayed image quality may only be measured subjectively; threshold contrast detail detectability is such a measure which can be related to the objective measures of image quality. The objective imagingcharacteristics suggest that Thoravision has a significant advantage over conventional Radiographyimaging systems. However, subjective measures have demonstrated that the image processing can have a significant effect on the perceived image quality. Thoravision has the potential to deliver a significantly improved image quality to clinicians with no increase in radiation exposure to the patient, or image quality may be maintained with a reduction in radiation exposure. Digital image processing is central to the efficiency with which it achieves this.

Pedro A López-saura - One of the best experts on this subject based on the ideXlab platform.

  • Adjuvant interferon gamma in patients with drug – resistant pulmonary tuberculosis: a pilot study
    BMC Infectious Diseases, 2004
    Co-Authors: Roberto Suárez-méndez, Idrian García-garcía, Norma Fernández-olivera, Magalys Valdés-quintana, María T Milanés-virelles, Dalia Carbonell, Delfina Machado-molina, Carmen M Valenzuela-silva, Pedro A López-saura
    Abstract:

    Background Tuberculosis (TB) is increasing in the world and drug-resistant (DR) disease beckons new treatments. Methods To evaluate the action of interferon (IFN) gamma as immunoadjuvant to chemotherapy on pulmonary DR-TB patients, a pilot, open label clinical trial was carried out in the Cuban reference ward for the management of this disease. The eight subjects existing in the country at the moment received, as in-patients, 1 × 10^6 IU of recombinant human IFN gamma intramuscularly, daily for one month and then three times per week up to 6 months as adjuvant to the indicated chemotherapy, according to their antibiograms and WHO guidelines. Sputum samples collection for direct smear observation and culture as well as routine clinical and Thorax Radiography assessments were done monthly. Results Sputum smears and cultures became negative for acid-fast-bacilli before three months of treatment in all patients. Lesion size was reduced at the end of 6 months treatment; the lesions disappeared in one case. Clinical improvement was also evident; body mass index increased in general. Interferon gamma was well tolerated. Few adverse events were registered, mostly mild; fever and arthralgias prevailed. Conclusions These data suggest that IFN gamma is useful and well tolerated as adjunctive therapy in patients with DR-TB. Further controlled clinical trials are encouraged.

Anna Kelaranta - One of the best experts on this subject based on the ideXlab platform.

  • incident air kerma to absorbed organ dose conversion factors for breast and lung in pa Thorax Radiography the effect of patient thickness and radiation quality
    Physica Medica, 2016
    Co-Authors: Anna Kelaranta, P Toroi, Peter Vock
    Abstract:

    Abstract Purpose Converting the measurable quantities to patient organ doses in projection Radiography is usually based on a standard-sized patient model and a specific radiation quality, which are likely to differ from the real situation. Large inaccuracies can therefore be obtained in organ doses, because organ doses are dependent on the exposure parameters, exposure geometry and patient anatomy. In this study, the effect of radiation quality and patient thickness on the organ dose conversion factors were determined. Methods In this study, the posterior–anterior projection radiograph of the Thorax was selected in order to determine the effect of radiation quality (tube voltages of 70–130 kV and total filtrations of 3 mmAl to 4 mmAl + 0.2 mmCu) and patient thickness (anterior–posterior thicknesses of 19.4–30.8 cm) on the breast and lung dose conversion factors. For this purpose, Monte Carlo simulation programs ImpactMC and PCXMC were used with computed tomography examination data of adult male and female patients and mathematical hermaphrodite phantoms, respectively. Results Compared to the reference beam quality and patient thickness, the relative variation range in organ dose conversion factors was up to 74% for different radiation qualities and 122% for different patient thicknesses. Conclusions Conversion factors should only be used with comprehensive understanding of the exposure conditions, considering the exposure parameters, exposure geometry and patient anatomy they are valid for. This study demonstrates that patient thickness-specific and radiation quality-specific conversion factors are needed in projection Radiography.