The ISRRT is proud to announce the Research Award winners for 2011: Warrington Hospital, United Kingdom

9/17/2011

The ISRRT is proud to announce the Research Award winners for 2011: Warrington Hospital, United Kingdom 

Above:  Anthony Manning-Stanley (Radiographer), Andrew England (Lecturer), Paula Evans (Clinical Lead radiographer - plain film), Maureen Taylor (Clinical Lead radiographer - A&E) and Louise Harding (Clinical Tutor)

Pelvic Orientation Study. 

Aim: To improve understanding of the effects of patient orientation on radiation dose and image quality for CR and DR radiographic examinations of the pelvis. To ascertain the optimum patient orientation, in relation to the automatic exposure control (AEC) chambers, for AP radiographic examinations of the pelvis.             

Design: Adult patients referred for AP pelvis examinations will be randomised into one of four groups according to the acquisition modality and the orientation of the patient. Patient orientation will be relative to the upper two outer Automatic Exposure Control (AEC) chambers. Radiation dose (entrance surface dose combined with backscatter and effective dose) will be calculated for each examination. Image quality will be blindly assessed by three observers (1 radiologist/2 reporting radiographers). To address the aim, the differences between image quality and radiation doses will be compared between the four options. 

Expected outcomes: 

Improved understanding of the effect of patient orientation on pelvic radiation dose and image quality. 

To establish the optimum orientation for both CR and DR examinations of the pelvis. 

Anticipated benefits: 

Improved understanding of the effect of orientation on positioning within AEC radiography. Reduction in radiation dose for pelvic radiography, improvement in image quality. Discussion regarding other areas where orientation may affect image quality and radiation dose.

Project objectives and long-term impact     

The proposed investigation will assess the effect of patient orientation on radiation dose and image quality for CR & DR examination of the pelvis. The problem with modern X-ray units is that the AEC chamber orientation is not marked on the table. Patients may be radiographed with either their head or feet closest to the two upper outer chambers which are routinely employed in pelvic radiography. Therefore, there could be different anatomy overlying the chambers. As a result, exposures will be terminated following different levels of radiation exposure and thus it is possible that orientation can significantly affect the radiation dose. In current clinical practice patient orientation on the table is usually determined by the existing position of the pillow, radiographer preference, additional examinations requested e.g. knee. As a consequence there will be some patients imaged with the head nearest the upper outer chambers and some with their feet, the radiation dose between the two could vary significantly. With the wide lattitude of both DR and CR systems it is possible for a radiation dose difference to exist between the techniques without a perceivable difference in image quality. This could lead to some pelvic examinations not following the as low as reasonably achievable (ALARA) principle. 

To have a better understanding of the effect of orientation is highly desirable. Pelvic radiography is the second commonest bucky examination with nearly 1 million episodes per year in the UK. Radiation dose reduction strategies in this area are desirable as this is a prevalent examination which irradiates the radiosensitive gonadal regions. To our knowledge patient orientation relating to AEC chambers is not standardised in any radiographic textbook or imaging department and therefore there could be wide differences in radiation dose as a consequence. Phantom studies have suggested that dose reduction of up to 40% may be achievable; this is even more important when you consider that serial pelvic radiographs are a frequent part of patient care following hip surgery. Our project has worldwide significance in that pelvic radiography is performed globally, DR and CR systems are widely available and there is a search to optimise examinations in order to achieve the lowest possible radiation doses. Providing evidence that orientation is important could have large global implications for radiation dose and image quality. A proven mechanism for reducing pelvic radiation dose could even affect the cumulative radiation dose from medical imaging procedures.