MRI : Magnetic Resonance Imaging ● Non- invasive medical imaging ○ Uses magnetic fields + radio waves ○ Able to see detailed structure + internal structure ■ Soft tissues ■ Bones Sequence Best For Appearance T1-weighted Anatomy, fat, hemorrhage Fat = bright; water = dark T2-weighted Edema, tumors, inflammation Water/fluid = bright FLAIR Brain lesions near ventricles suppresses CSF DWI Stroke (acute ischemia) Bright in early infarcts fMRI Brain activity (functional imaging) Measures changes in blood flow ● Used for… ○ Neurology (stroke, tumors) ○ Musculoskeletal(ligament and tendon tear) ○ Cardiology (cardiac functional test) ○ Oncology (Tumor detection) Methods ● H nuclei within patient’s body will align with magnetic fields ● RF pulse applied = will disturb this alignment ● Once RF field stops ○ Proton returns to equilibrium = sends signals ○ Signals converted to image ● Advantage there is no ionization radiation ● Soft tissue not damaged ● Gadolinium base is used for contrast agent ○ Better imaging ○ Blood vessels, inflammation, tumors could be seen ○ Must be avoided in patients with kidney disease ■ Will have risk of NSF ■ Patients with GFR less than 30mL ■ CKD stage 4-5 patients are in danger ■ Will have signs and symptoms withing days or weeks in exposure to GBCA ■ Thickening in skin and stiffer joints ■ Internal organ fibrosis(severe) ■ Sometimes fatal Safety concerns ● No long term health effects caused from magnetic field ● Could alter patients with pacemaker or defibrillator ● Metal implants could be impacted by magnetic fields ● Physiological problems ○ Claustrophobia ○ Pregnancy