Magnetic Resonance Imaging FRCR Physics Lectures Anna Beaumont
Magnetic Resonance Imaging FRCR Physics Lectures Anna Beaumont anna. beaumont@hey. nhs. uk (Acknowledgments: Dr Gary Liney)
In The Beginning…. Sagittal image of the human head (from Alfidi et al. 1982) …‘Nuclear’ dropped and becomes MRI “. . we feel sure that in the very near future commercial machines capable of producing medical images for hospital use will be available. ” P. Mansfield and P. G. Morris 1982
MRI Today l MRI is the imaging modality of choice in the brain and spinal cord l Soft-tissue contrast with large degree of manipulation, non-ionising radiation, multi-planar in any orientation. l Many more areas of use (eg breast, cardiac, wholebody scans). l Advanced techniques currently being developed for clinical practice. . .
FRCR MRI Syllabus l 4. 16 Nuclear Magnetic Resonance – Nuclear spin angular momentum and nuclear magnetic moment – Bulk magnetisation and the effect of magnetic field strength – Precession in a magnetic field and the Larmor equation – Resonance with radiofrequency pulses – Relaxation mechanisms and relaxation times – Free induction decay signal
FRCR MRI Syllabus l 4. 17 Magnetic Resonance Imaging – Construction, function and operation of a superconducting MRI scanner – Permanent and resistive magnets – Radiofrequency receiver coils – Spin-echo pulse sequence – Spatial localisation of the signal – K-space, image acquisition and image reconstruction – Multi-echo, fast spin-echo and single shot techniques – Gradient echo imaging- basic spoiled and non-spoiled techniques
FRCR MRI Syllabus l 4. 17 Magnetic Resonance Imaging (cont) – Tissue suppression methods- short TI inversion recovery (STIR), fluid attenuated inversion recovery (FLAIR) and fat saturation – Standard gadolinium extracellular space contrast agents – Other MR contrast agents – Magnetic resonance angiography – Basic principles of diffusion techniques and diffusion weighted imaging – Dynamic contrast enhancement and perfusion imaging
FRCR MRI Syllabus l 4. 17 Magnetic Resonance Imaging (cont) – Principles of magnetic resonance spectroscopy (MRS) – Spatial misregistration, chemical shift, susceptibility, motion, flow and other artefacts – Cell biology principles underpinning dynamic contrast enhanced and diffusion weighted MRI
FRCR MRI Syllabus l 4. 18 Safety in Magnetic Resonance Imaging – Static magnetic field- projectiles, induced voltage, implants – Fringe field and controlled area – Time-varying gradient fields- eddy currents, stimulation, implanted devices, acoustic noise – Radiofrequency fields- specific absorption rate, heating – Safety of patients, staff and members of the public – Pregnant patients – Shielding and imaging room design – Safety guidelines for Magnetic Resonance Imaging equipment in clinical use
Further Reading…
Resources Hashemi, Bradley, Lisanti Penelope Allisy Roberts, Jerry Williams Mc. Robbie, Moore, Graves, Prince Westbrook Blink
Resources: Online l www. onlinemri. co. uk l http: //mri-q. com l RITI system – www. e-lfh. org. uk/programmes/radiology l www. imaios. com/en/e-Courses/e-MRI
Programme of these lectures Date Covered 6/10/15 1: Basic Physics 17/11/15 6: Basic Pulse Sequences 13/10/15 2: Spatial Encoding 26/11/15 7: More Complex Techniques – Part I 20/10/15 3: Equipment & Safety 3/12/15 8: More Complex Techniques – Part II (incl. case studies presented by Dr David Salvage, Consultant Radiologist) 29/10/15 4: Scanner session 8/12/15 9: Artefacts 10/11/15 5: K Space & Imaging Parameters 10/12/15 10: Revision Questions
- Slides: 12