To have standardised terminology across all DR equipment in one Hospital Trust which will act as a visual indicator to the radiographer that the image is correctly exposed and within national Dose Reference Levels (DRL’s)
[i] To test if EI and DI was appropriately calibrated in 8 DR rooms across multiple sites in a busy Hospital Trust in the UK.
[ii] To investigate if IEC 62494-1 would give the radiographer a reliable visual indicator of a correctly exposed image.
[iii] To identify if...
Digital Radiography has a high Detective Quantum Efficiency (DQE) which means that less radiation exposure is needed to achieve the same image quality,
relative to conventional film screen radiography (FS).
Digital detectors offer the advantages of a wide dynamic range,
adjustable image processing,
better image quality,
rapid image acquisition and image access at remote locations.
 In addition,
digital image processing can also compensate 100% for underexposure and more than 500% for overexposure(see figure 1).
DR processing amplifies the signal when underexposed and decreases it...
Findings and procedure details
Ethical and Research Governance Approval was sought and obtained.
Eight DR rooms using equipment from three different manufacturers were investigated in one UK Trust.
This included three Siemens Ysio units,
two Carestream Evolution and three hybrid systems consisting of Shimadzu consoles and Canon detectors.
The methodology was divided into six phases.
Initially the EI used by a variety of DR manufacturers was investigated to check if it was calibrated according the IEC standard.
Each manufacturer was contacted by email to ascertain how their EI...
The initial dose audit revealed exposures for pelvis and lateral lumbar spines were above the DRL in the hybrid systems.
Image optimisation was implemented whereby the “10kVp rule” was employed.
Pre-programmed automatic exposure control (AEC) exposures for pelvis and lateral lumbar spines on the hybrid units were altered by raising the kVp by 10 kVp and halving the mAs to achieve the required density,
hence reducing the exposure to the patient.
The second dose audit performed after recalibration of EI values revealed exposures for pelvis...
Mrs Grainne Forsythe
Lead reporting radiographer
Dr Philip Doyle,
Belfast health and Social Care Trust,
Radiological Sciences and Imaging,
Foster Green Hospital,
Dr Sonyia McFadden
Diagnostic Lecturer in the School of Health Sciences
University of Ulster
Digital imaging systems for plain radiography.
Are exposure index values consistent in clinical practice? A multi-manufacturer investigation.
Radiation Protection Dosimetry. 2010,Vol 129,
Educating staff about digital radiography.
Radiology Management, 2014 May-June ; 36(3):34-40
An assessment of exposure indices in computed radiography...