5 TISSUE COLOURS Bone Marrow: normally fatty white on T1White on T2replaced with edema or other pathology(dark on T1)Bone cortex, stones, and ligamentsdark on everythingContusion is white
6 TISSUE COLOURS Tumor: hypervascular (neovascularity): white with gadolinium
7 Approach to protocols T1 -MRI with dark fluid T2 -MRI with white water, inflammationcartilage is blackSTIR- T2 with dark fatProton Density - cartilage is greycan suppress the fatGadolinium enhanced - with fat suppressionT1bright blooddark fatPathology bright
8 Magnetic resonance imaging (MRI) of the spine A noninvasive procedure to evaluate different types of tissue, includingthe spinal cordintervertebral disksspaces between the vertebrae through which the nerves traveldistinguish healthy tissue from diseased tissue.
9 Magnetic resonance imaging (MRI) of the spine The cervical, thoracic and lumbar spine MRI should be scanned in individual sections.The scan protocol parameter like e.g. the field of view (FOV), slice thickness and matrix are usually different for cervical, thoracic and lumbar spine MRI, but the method is similar.
10 Magnetic resonance imaging (MRI) of the spine The standard views in the basic spinal MRI scan to create detailed slices (cross sections) aresagittal T1 weighted and T2 weighted images over the whole body parttransversal (e.g. multi angle oblique) over the region of interest with different pulse sequences according to the result of the sagittal slices.Additional views or different types of pulse sequences like fat suppression, fluid attenuation inversion recovery (FLAIR) or diffusion weighted imaging are created dependent on the indication.
11 Indications:Neurological deficit, evidence of radiculopathy, cauda equina compressionPrimary tumors or drop metastasesInfection/inflammatory disease, multiple sclerosisPostoperative evaluation of lumbar spine: disk vs. scarEvaluation of syrinxLocalized back pain with no radiculopathy (leg pain)
12 Contrast enhanced MRI Delineate infections, malignancies show a syrinx cavitysupport to differentiate the postoperative conditions. After surgery for disk disease, significant fibrosis can occur in the spine. This scarring can mimic residual disk herniation.Magnetic resonance myelography evaluates spinal stenosis and various intervertebral discs can be imaged with multi angle oblique techniques.
13 Cine series can be used to show true range of motion studies of parts of the spine. Advanced open MRI devices are developed to perform positional scans in the position of pain or symptom (e.g. Upright™ MRI formerly Stand-Up MRI).
14 ContraindicationsMRI systems use strong magnetic fields that attract any ferromagnetic objects with enormous force.Caused by the potential risk of heating, produced from the radio frequency pulses during the MRI procedure, metallic objects like wires, foreign bodies and other implants needs to be checked for compatibility.High field MRI requires particular safety precautions.In addition, any device or MRI equipment that enters the magnet room has to be MR compatible.MRI examinations are safe and harmless, if these MRI risks are observed and regulations are followed.
15 Safety concerns in magnetic resonance imaging include: The magnetic field strength;possible 'missile effects' caused by magnetic forces;the potential for heating of body tissue due to the application of the radio frequency energy;the effects on implanted active devices such as cardiac pacemakers or insulin pumps;magnetic torque effects on indwelling metal (clips, etc.);the audible acoustic noise;danger due to cryogenic liquids;the application of contrast medium;
16 MRI Safety GuidanceIt is important to remember when working around a superconducting magnet that the magnetic field is always on.Under usual working conditions the field is never turned off.Attention must be paid to keep all ferromagnetic items at an adequate distance from the magnet.Ferromagnetic objects which came accidentally under the influence of these strong magnets can injure or kill individuals in or nearby the magnet, or can seriously damage every hardware, the magnet itself, the cooling system.
17 MRI Safety GuidanceThe doors leading to a magnet room should be closed at all times except when entering or exiting the room.Every person working in or entering the magnet room or adjacent rooms with a magnetic field has to be instructed about the dangers.This should include the patient, intensive-care staff, and maintenance-, service- and cleaning personnel, etc..
18 MRI Safety GuidanceLeads or wires that are used in the magnet bore during imaging procedures, should not form large-radius wire loops.The patient’s skin should not be in contact with the inner bore of the magnet.
19 MRI Safety GuidanceThe outflow from cryogens like liquid helium is improbable during normal operation and not a real danger for patients
20 MRI contrastThe safety of MRI contrast agents is tested in drug trials and they have a high compatibility with very few side effects.The variations of the side effects and possible contraindications are similar to X-ray contrast medium, but very rare.In general, an adverse reaction increases with the quantity of the MRI contrast medium and also with the osmolarity of the compound.
29 Cervical Neurography (Brachial Plexus) Use the Cardiac or phased array Body coil rather than the spine coilCor images should be 3mm skip 0mm, Ax Images 4mm skip 1.5FOV should be from C4 through T1Use T2 FSE/TSE FS if STIR images failCan add flow suppression or sat bands above, below, and anteriorPost process thick slab MIPs of STIR images if possible
39 L-Spine MRI Trauma L-Spine MRI Sagittal T1 SE, Sagittal FSEIR, Axial T2 FSE with fat sat.Target axials to abnormality.No IV contrast.Post-Op L-Spine MRITarget axials to abnormality at level of surgeryIV contrast.Can add Sag GRE to rule out hemorrhage
46 MRI KNEECommon IndicationsKnee painKnee instabilityKnee mass
47 Otherwise schedule anytime. First AskIs there a mass?______ When did you first discover the mass?_______________________Does the problem relate to a recent injury? YES NO DATE_____________________Where does the knee hurt ( FRONT - BACK - INSIDE - OUTSIDE )?Have you had surgery on your knee? YES NO DATE__________________________Have you had an x-ray?If “mass” then schedule in early morning with Radiologist monitoring. Patient may need gadoliniumOtherwise schedule anytime.Instruct patient to bring x-rays if available.
48 Patient Preparation:· Fill out safety screening and clinical information form· Vitamin E capsule on the site of symptoms and on any masses· Measure distance left or right from centerline of magnet
49 Coil: Extremity. Slightly externally rotate the foot by about degrees to stretch the anterior cruciate ligament.Pack some cushions around the knee to help it stay motion-free. A small cushion under the ankle helps to keep the leg straight.Landmark: inferior region of patella.Patient Positioning: Supine, feet first.
51 Series 1: Axial Proton Density Series 2: Sagittal Proton DensityOblique to the intercondylar notchInclude all of medial and lateral menisci. Subcutaneous fat medial and lateral to knee joint may be excluded. If more slices are required, increase TR.
52 Series 3: Coronal Proton DensityOblique perpendicular to series 2.If more slices are required, increase TR.Keep TR > 3000 and ETL < 16If there is bone abnormality or soft tissue mass then it may be necessary to increase FOV.Series 4: Coronal T2 Fat Sat (same as series 3 above) Series 5: Optional Cartilage:Usually cartilage is well seen on the proton density sequences (series 1-3). However this in patients with cartilaginous injuries, this extra sequence optimized for cartilage may be useful.Do not film this sequence. It is viewed on the computer work station.
53 If there is a Solid Mass suspicious for CANCER: then make sure there is a vitamin E capsule marking the site of the mass and perform dynamic 2D or 3D Gd MRA during the injection of single dose gadolinium followed by axial and either sagittal or coronal T1 fat sat spin echo sequences
54 If there is hemophilia or if PVNS is suspected: Do a gradient echo sequenceSeries 8: Optional Gradient Echo:This sequence is useful for patient with hemophilia or PVNSMake sure to cover all of the synovium