Appropriate Magnetic Resonance Imaging Ordering #MMPMID33351416
Ashby K; Adams BN; Shetty M
StatPearls-/-ä 2024[Jan]; ä (ä): ä PMID33351416show ga
Magnetic resonance imaging (MRI) is a diagnostic technique useful for noninvasive visualization of organs and soft tissue structures. The ability to evaluate for structural integrity lends MRI for imaging the neural axis and large joints of the musculoskeletal system where it was used most heavily during its infancy. Since that time, MR's scope and application have broadened significantly and now encompasses abdominopelvic and cardiac imaging. Clinicians frequently order MRI to characterize soft tissue and osseous lesions or masses. In some cases, the varying MRI sequences can determine the composition of these abnormalities. For example, MRI elastography can diagnose and surveil hepatic fibrosis sparing the patient from an invasive and repetitive biopsy. MR angiography, using both contrast-enhanced and non-contrast techniques, can diagnose vascular occlusive disease and stenosis. Faster scan times and gating techniques minimizing cardiac and respiratory motion make MRI a useful non-invasive tool for cardiac evaluations of structure, function, and myocardial perfusion. A major advantage of MRI is the ability to produce high-quality images with superior soft-tissue contrast without using ionizing radiation. The magnet generates images based on the specific and unique magnetic properties of the tissues driven by the spin properties of hydrogen molecules. This makes MRI especially useful to evaluate "high radiation risk" patients like pregnant women and children. MRI is also valuable for patients with chronic conditions requiring routine imaging surveillance, such as multiple sclerosis and inflammatory bowel diseases. MRI does not exist without hazard - the magnetic field can be dangerous and strict parameters are in place to ensure patient safety. Pre- imaging screening protocols are in place to assess the patient's risk factors ranging from occupational exposures to surgically implanted devices determined to be incompatible with the magnetic field. Though many of the newer generation implanted devices are MR compatible, it is crucial to consult with both the radiologist and MR technologists. The magnetic field can alter implanted devices and result in loss of function, positioning, and temperature changes. Additionally, while some prosthetic devices- like heart valves, stents, and artificial joints- are MR safe, they may cause signal artifacts that limit the diagnostic quality of the exam. While in no way all-inclusive, this article provides information for clinicians to consider when ordering MR imaging.
StatPearls-/-ä 2024 ; ä (ä): ä
