Module - Diagnostic Radiology: Image Optimisation and Patient Dose Measurement


Work-based learning outcomes


  1. Perform measurements to assess image quality in various types of equipment, to include computer radiography, digital radiography, CT and image intensifier systems
  2. Perform appropriate measurements and/or calculations to assess patient dose for a range of examinations, which must include examples from radiographic, fluoroscopic, CT and mammographic examinations
  3. Analyse patient dose measurements and, in the context of optimisation, draw conclusions
  4. Assess, by simulation and/or measurement, patient dose reduction interventions
  5. Calculate organ dose and effective dose, relate dose to risk and effectively communicate the risk

Work-based Competencies


Learning outcome Title Knowledge
1 2

Review and critically appraise the patient dose measurement framework

  • Internal policies and procedures and national guidance
2 1

Review and analyse methods for assessment of image quality in a range of diagnostics radiology equipment, including computed radiography, digital radiography, CT and image intensifier systems

  • Standards for image quality
  • Methods for measurement of image quality
  • How images are formed, processed and displayed
  • Data processing of images
  • Test equipment for assessment of image quality
  • Parameters to describe image quality
3 1

Undertake measurements to assess image quality in a range of diagnostics radiology equipment, including computed radiography, digital radiography, CT and image intensifier systems, and interpret results in the context of the clinical use

  • Factors affecting image quality
  • Artefacts
  • Image quality requirements under different clinical situations
  • Implications for patient treatment
  • Performance for different types of image detectors and appropriateness for various types of imaging
  • Test equipment to match task
4 2

Undertake measurements to assess the patient dose in the equipment settings used to assess image quality above and advise on appropriate diagnostic reference levels

  • Operation of patient dose indicators on equipment and their limitations
  • Units used to describe patient dose
  • Translation of measured values into dose quantities and effective dose
  • Methods of calibration
  • Risks to the patient
5 1

Review and develop parameters for assessing clinical image quality with clinical staff

  • Parameters used to measure and describe image quality
  • Clinical requirements and how the various factors can affect clinical image quality
6 3,4

Review the outcome of image quality and patient dose measurements in a range of systems and recommend optimisation strategies Assess by simulation or measurement the effect of the optimisation suggested

  • National DRL/local DRL procedures and correct application
  • Image quality/patient dose trade-off
  • Effect of exposure parameters on image quality and patient dose
7 5

Calculate organ dose and effective dose for a range of investigations

  • Relevant software and how the input factors affect organ dose and effective dose
8 5

Calculate radiation risks and communicate them effectively to various staff groups and the patient

  • Everyday risks in the context of radiation risks
  • Benefits and detriments of radiation

Work-based assessment


Complete 2 Case-Based Discussion(s)
Complete 1 of the following DOPS and/or OCEs
Type Title
DOPS Undertake CTDIw measurement
DOPS Discuss optimisation strategies with users and the installer during commissioning of diagnostic X-ray equipment
DOPS Assess image quality for a diagnostic X-ray machine using a simple test object
DOPS Undertake entrance surface dose measurements for a fluoroscopy system
DOPS Analyse and interpret data from a multislice CT phantom
DOPS Use a (commerically available) software program to calculate a patient dose
DOPS Measure the image quality in fluoroscopy and acqusition modes at varying pulse / frame rates on an image intensifier or flat panel screening system
DOPS Measure the image quality for a mammography unit using a variety of test objects
OCE Explain CTDIw meaurement to a clinical team member
OCE Present patient dose data to a multidisciplinary audience
OCE Advise patients undergoing therapeutic isotope administration in Nuclear Medicine.
OCE Calculate a patient dose for external radiation exposure and discuss the dose and risk with the patient.
OCE Calculate patient dose for internal radiation exposure and discuss the dose and risk with the patient where possible.