Imaging with Non Ionizing Radiation 1

Module details

Title

Imaging with Non Ionizing Radiation 1

Type

Specialist

Module code

SPE154

Credits

20

Requirement

Compulsory

Aim of this module

This module provides the trainee with the knowledge that underpins the specialist rotation in Imaging with Non-Ionising Radiation in the second year of the MSc.

For the trainee to use a range of equipment and techniques in ultrasound imaging and understand the effects of image acquisition parameters.

Ultrasound Imaging

For the trainee to use a range of equipment and techniques in ultrasound imaging and understand the effects of image acquisition parameters. 

Magnetic Resonance Imaging 

For the trainee to use a range of equipment and techniques in magnetic resonance imaging and understand the effects of image acquisition parameters.

Diagnostic Equipment Performance

To introduce the trainee to a range of equipment, techniques and performance measurements used in non-ionising radiation.

Risk, Safety and Bioeffects 

To introduce the trainee to a range of equipment, techniques and exposure measurements.

Submodules

Learning outcomes

1. Discuss the physical processes behind image formation using non-ionising radiation.
2. Explain the normal and pathological appearances of images and identify common imaging artefacts.
3. Discuss the physical principles and operation of ultrasound and MRI.
4. Explain the factors that affect system performance.
5. Critically appraise the legislation and guidance that ensures safe working.

Indicative content

Fundamentals

• Mathematical and physical principles behind the formation of the image
  • MRI
  • Ultrasound including Doppler ultrasound
  • Laser imaging
  • Image registration in multiplanar imaging, including MRI, CT, PET and single photon emission computed tomography (SPECT)
• The physics of electromagnetic and acoustic radiation interactions with matter
• The key parameters that define optimal image quality for a range of clinical/research applications

Clinical

• Normal and pathological appearances of MRI and ultrasound images
• Common imaging artefacts
• Results from analyses (e.g. qualitative, quantitative) and the context in which they were acquired

Technical

• Detailed understanding of the design principles and operation of MRI
  • Relaxation mechanisms
  • Pulse sequences and image generation
  • Instrumentation
  • The physics of MRI safety issues

• Detailed understanding of the design principles and operation of ultrasound
  • Linear and non-linear propagation
  • Generation and detection – transducers, piezoelectric effect
  • Interactions with tissue – diffraction, reflection, scatter, absorption
  • B-scanner principles – Time Gain Compensation, signal processing, image storage, array types
  • Resolution – focusing
  • Beam steering
  • Doppler imaging
• How to assess system performance and perform comparative evaluations
• Monitoring devices for RF, electric and magnetic fields
• Measurement of ultrasound beams and ultrasound power levels

Non-Ionising Radiation

• Sources physical properties, interactions with matter, biological effects, measurement, applications and safety of:
  • UV
  • intense light sources
  • lasers
  • infrared
  • microwaves
  • RF
  • electric and magnetic fields
• The clinical measurements that use non-ionising radiation, for example:
  • red/infrared light to measure O2 content in blood
  • infrared to measure microvascular circulation
  • UV to measure skin sensitivity
• The relevant guidelines, documents and standard operating procedures for safe practice with regard to the use of non-ionising radiation in the clinical environment
• The EM interactions between implanted devices and the MRI environment
• The safety issues and exposure limitations relevant to different patient groups
• Rationale behind safety standards

Activities

Ultrasound Imaging 

• Observe a range of clinical diagnostic ultrasound examinations undertaken in patients within care pathways, including obstetrics, vascular, breast and cardiac, and discuss the clinical application, advantages/complementary features of ultrasound with respect to other modalities within each care pathway.
• Compile a portfolio of anonymised images, commenting on the typical diagnostic appearances of human anatomy and pathology under varying imaging conditions and discussing the role that artefacts play in modifying the image.
• Use a phantom/volunteer to investigate the effects of clinical settings on the image, e.g. tissue harmonic imaging (THI), compound imaging, frequency selection, PRF, TCG setting.
• Investigate the effect of user-selectable parameters on volunteers (with appropriate permission in place) or suitable phantoms and describe how to maximise the image quality.
• Note parameters used during clinical practice and compare to the theoretical ideal parameters, i.e. frequency, power output, safety indices and discuss your findings with your training supervisor.

Magnetic Resonance Imaging 

• Observe a range of clinical MRI examinations undertaken in patients within care pathways, including neuro, oncology, musculoskeletal, etc., and discuss the clinical application, advantages/complementary features of Magnetic Resonance Imaging (MRI) with respect to other modalities within each care pathway.
• Compile a portfolio of anonymised images, commenting on the typical diagnostic appearances of human anatomy and pathology under varying imaging conditions and discussing the role that artefacts play in modifying the image.
• Observe a number of advanced/specialist MR examinations, including dynamic contrast-enhanced MRI, contrast-enhanced MR angiography and cardiac imaging, and discuss the clinical application of these techniques to improve the diagnosis and management within care pathways with your training supervisor.
• Attend a meeting at which the outcome of a clinical audit, research, innovation or service development is presented, and discuss with your training supervisor how evidence-based practice is implemented with respect to MRI.
• Investigate the effect of user-selectable parameters on volunteers (with appropriate permission in place) or suitable phantoms and describe how to maximise the image quality.
• Note parameters used during clinical practice and compare with the theoretical ideal parameters, i.e. Echo Time (TE)/ Repetition Time (TR)/flip angle, and discuss your findings with your training supervisor.

Diagnostic Equipment Performance

• Observe a range of quality control programmes where non-ionising radiation is used and critically review each programme, identifying good practice and making recommendations to your training supervisor for potential improvements.
• Identify and investigate examples of poor imaging performance and produce a written report identifying the cause(s) and recommending solutions to resolve the problem, and, where possible, providing practical evidence of the effect of your recommendations. Examples include images from a multi-coil array where one or more coil elements have failed. Images from an ultrasound probe with delamination or damaged crystals, or EMI or inappropriate frequency.
• Obtain information on a wide range of commercially available non-ionising imaging equipment and, where necessary, arrange visits to see equipment not available at the training centre and critically evaluate the clinical use of each system with respect to diagnostics and/or treatment.
• Gain an awareness of recent trends in ultrasound systems for example ‘point-of-care’ scanners with minimal choice of parameters or new clinical specialities with increasing ultrasound application (emergency department, respiratory), and reflect on the potential each device has to improve diagnostics.
• Investigate the development of a new hardware feature (e.g. development of 70 cm wide-bore or multichannel transmit systems) and present your findings at a departmental meeting.

Risk, Safety and Bioeffects 

• Observe the day-to-day working of a non-ionising radiation imaging facility and critically review the facilities and working practice, discuss your observations with members of the multidisciplinary team, including issues around different field strength MR systems.
• Discuss a range of MR safe, MR conditional and MR unsafe devices/equipment, e.g. anaesthetic monitoring equipment, wheelchairs, MR conditional pacemakers, with members of the multidisciplinary team.
• Review patient safety checklists and observe a number of patients being screened (with their permission) against the checklist. Reflect on the impact of patient safety checklists on reducing error and improving patient safety.
• Perform a non-ionising radiation safety audit and discuss with your supervisor.
• Critically review the local health and safety rules and write a local safety policy for scanning volunteers that could be used as part of a research application to an ethics committee.
• Review the bioeffects present when using US and carry out a risk assessment of a particular application, e.g. 3D foetal scanning or contrast-enhanced scanning. Discuss your findings with your supervisor.
• Review the risks and contraindications of MR contrast agents.
• Participate in the electrical safety testing of a new non-ionising radiation imaging modality/facility.