Images are assessed for quality and completeness prior to submitting for reporting or where appropriate, adjusting treatments
- The quality of the image should be such that the professional interpreting the image is able to answer the clinical question being asked.
- In diagnostic imaging, this implies the image is of sufficient diagnostic quality
- In radiation therapy, this implies the image is of sufficient quality to direct planning and treatment
- Submitting suboptimal images affects the interpretation of the image and may impact the patient’s care and outcomes1:
- An image of poor diagnostic quality may lead to misdiagnosis, suboptimal decisions or delays in care for the patient
- Repeat images may result in unnecessary exposure to radiation for the patient and/or MRT, and increased costs for the healthcare system
- MRTs are responsible for the critical evaluation of images, including2:
- Review of images for positioning and quality
- Decisions on acceptability of images, including whether or not to repeat imaging
- A judgment on image quality requires an understanding of the clinical question that is being investigated.
- “Does this image clearly demonstrate the information necessary to answer the clinical question?”
- Image quality is best judged using a logical and analytical process, with consistent standards across a department and facility1,3,4 .
- The overall density/signal to noise and contrast/weighting of the image is verified
- The appropriate anatomy is demonstrated
- Correct patient positioning (angles, planes and coverage) is verified
- MRTs evaluate common issues affecting image quality5:
- Image artefacts
- In addition, MRTs verify processing, labeling and annotation:
- Correct patient demographic information
- All required post processing is complete
- Images are labeled correctly
- Image markers are correctly placed
- If an image is not of the required diagnostic quality to answer the clinical question, then repeat imaging may be necessary.
- Images that are diagnostic, with clearly identifiable pathology, should not be repeated because of suboptimal image quality
- Before an imaging procedure is repeated, an MRT considers:
- Have factors that contributed to suboptimal image been identified and corrected?
- Are there any specific patient factors or circumstances that affect the appropriateness of repeat imaging?
- Is there a need to consult another healthcare provider?
- Suboptimal images are retained for quality control activities such as the reject analysis.
- Each suboptimal image is an opportunity for analysis and reflection on technique used3.
- A critical approach to image quality provides an opportunity to improve the quality of care for future patients
- Reject analysis, using ‘rejected’ images to determine the cause of the rejection and repeat imaging, is performed periodically to formalize analysis1,6,7.
- The objective of reject analysis is to reduce the number of repeated examinations by correcting problems and improving skills6
- Images of suboptimal quality are sorted according to the reason for rejection
- Trends are identified and analyzed in an attempt to identify the source of the problem
- Health Canada suggests that guidelines for an effective reject-repeat analysis program are formally documented within the department’s quality control protocol manual8
- Each identified problem requires an appropriate corrective action and reasons for decreased image quality are determined and corrected so future patients are not affected.
- All action taken is reported and documented so that MRTs may benefit from the learnings of the reject analysis in the future1.
- MRTs are familiar with the policy concerning repeat imaging and reject analysis at their own facility.
International Atomic Energy Agency. Lecture 23: Organizing a QC in diagnostic radiology. IAEA Training Material on Radiation Protection in Diagnostic and Interventional Radiology. 2012.
Canadian Association of Radiologists. CAR Standards for General (Plain) Radiography. June 2000. Available from: http://old.car.ca/Files/general_radiography.pdf. [Accessed 22 Dec 2017]
Carlton RR, Adler AM, eds. Principles of Radiographic Imaging: An Art and a Science. 4th ed. Clifton Park, NY: Thomson; 2006.
Campeau FE. Radiography: Technology, Environment, Professionalism. Philadelphia, PA: Lipincott, Williams and Wilkins; 1999.
Papp J. Quality Management in the Imaging Sciences. 4th ed. St. Louis, MO: Mosby Elsevier; 2011.
International Atomic Energy Agency website. Radiation protection of patients. Available from: https://rpop.iaea.org/RPOP/RPoP/Content/InformationFor/HealthProfessionals/1_Radiology/Radiography.htm. [Accessed 21 Feb 2013]
European Commission. European Guidelines on Quality Criteria for Diagnostic Radiographic Images. www.sprmn.pt. 1996. Available from: https://www.sprmn.pt/pdf/EuropeanGuidelineseur16260.pdf. [Accessed 23 May 2018]
Health Canada. Diagnostic X-Ray Imaging Quality Assurance: An Overview. Available from:
https://www.canada.ca/en/health-canada/services/environmental-workplace-health/reports-publications/radiation/diagnostic-imaging-quality-assurance-overview.html. [Accessed 27 Apr 2018]