MRI Student orientation Flinders medical centre
overview Why MRI? Basic physics overview Safety Departmental overview Equipment What students can do in our department Goals
Why mri? Challenging Rewarding Engaging Interesting Cutting edge of technology Rapidly evolving imaging modality Always learning and developmental opportunities, including sub-specialities Cardiac Breast
Why mri? Work with a dynamic, supportive and flexible team environment Amazing pictures over a wide variety of applications
cardiac
breast
orthopaedic
Body
neuro
vascular
is it for you?? Excellent patient care and communication skills required High level of technical knowledge and expertise Ability to work independently Participation in after hours, weekends, and on call roster Education! Structured training program including training modules AIR level 1 accreditation IV cannulation (in-house training) Post graduate university qualification
Physics review When an external magnetic field is applied, H atoms align either parallel or antiparallel with the magnetic field
Physics review A radiofrequency wave is applied at the resonant frequency to the spinning protons The protons jump to a higher energy level and are ‘flipped’ into the transverse plane
PHYSICS REVIEW
PHYSICS REVIEW When the RF pulse is switched off, the spins start to relax back to their original state
Physics review An antenna measures the signal coming from the excited protons
PHYSICS REVIEW T1 RELAXATION
PHYSICS REVIEW T2 RELAXATION
safety Arguably the most important consideration in MRI Large invisible magnetic fields which ARE ALWAYS ON All students MUST be accompanied by an MRI radiographer in the scan room at all times Department is ‘zoned’ and access to inner zones is restricted Past safety incidents have resulted in injury and even death
hazards Projectile effect Scanner can cause ferrous objects to accelerate towards it Hair pins can reach speeds of 40mph at 1.5T
hazards Burns Tattoo burn Generally caused by use of electrically conductive material inside magnet bore Occassionally tattoos and tattooed eye liner can heat if they contain iron oxide Tattoo burn
hazards ALSO: Twisting/torsion of devices or implants Image artifacts from device interference and metallic foreign bodies Device malfunction
safety All patient implants need to be investigated for safety All equipment entering scan room must be approved as MRI compatible and all conditions adhered to (e.g. distance from scanner) Any persons entering scan room must complete safety questionnaire, remove all loose metal, and be accompanied by MRI radiographer
safety Emergency shut down (‘quench’) of scanner due to life-threatening projectile costs between $20,000-$500,000
Departmental overview 2 scanners – 1.5T & 3T 3T Holds (most) medicare licences Billable pts Outpatients Inpatients from FPH/Noarlunga/Repat Rapid knee assessment clinic Small amount of cardiac
Departmental overview Non-billable magnet FMC inpatients inc ICCU & NNU Outpatient non billable studies e.g. most pelvic work Work cover pts Pts not safe for 3T but safe on 1.5T e.g. pregnant, surgical implants etc Cardiac list – 4 lists weekly General anaesthetic list – 1 list weekly Breast scanning – approx 4 patients per week
workflow Very busy department Usually 2 radiographers per scanner Up to 3 month waiting list for non urgent patients Usually 2 radiographers per scanner one scanning other one getting next patient ready change into scrubs go over safety questionnaire chase up last minute safety queries explain procedure cannulate set up dynamic/pump injector transfer into MRI safe wheelchair or slide onto scan table if necessary
equipment Very expensive and must be handled with care Antennae used for capturing image must fit as closely as possible to anatomy → multiple coils which are changed depending on anatomy Two different scanners have quite different equipment, including coils and table/docking systems
Siemens aera (1.5T)
Siemens trio (3T)
What you can do Limited opportunities for students to scan due to complicated nature of MRI Where time, radiographers will endeavour to teach some very basic scanning skills so that students can get a feel for what MRI scanning is like Knee Brain Lumbar spine
What you can do MRI takes a long time to acquire images – average examination time is around 30 mins Scanning conditions can quickly become stressful and radiographers will occassionally not have much time for teaching
What you can do Students can get involved by Getting patients changed Help change bed linen and coils Position patients and advance into scanner Assist in patient transfers Scanning paperwork Accessing reference books/computer programs for anatomy and pathology information
Student goals By the end of your week in MRI, you should be able to: Select/change coils for common examinations Be able to scan either knee/brain/Lspine Have a basic understanding of MRI physics Understand the main safety contraindications to MRI scanning
references MRI suite orientation folder MRI suite training program 2012 Fundamentals of MRI Course program. Marc Agzarian 2012. Siemens healthcare www.healthcare.siemens.com http://physiology-physics.blogspot.com.au/2010/06/understanding-basic-principles-of.html http://www.mikepuddephat.com/Page/1603/Principles-of-magnetic-resonance-imaging http://www.revisemri.com/questions/basicphysics/t2contrast