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Chest MRI
Definition:
A chest MRI uses powerful magnets and radio waves to construct pictures of the body. Unlike conventional radiography and computed tomographic (CT) imaging, which make use of potentially harmful radiation (x-rays) that passes through a patient to generate images, magnetic resonance imaging (MRI) is based on the magnetic properties of atoms. Text Continues Below
A powerful magnet generates a magnetic field roughly 10,000 times stronger than the Earth's. A very small percentage of hydrogen atoms within the body will align with this field. Radio wave pulses are broadcast towards the aligned hydrogen atoms in tissues of interest, returning a signal of their own. The subtle differing characteristics of that signal from different tissues enables MRI to differentiate between various organs, and potentially, provide contrast between benign and malignant tissue. Any imaging plane, or "slice", can be projected, and then stored in a computer or printed on film. MRI can easily be performed through clothing and bones, however, certain types of metal in or around the area of interest can cause significant errors in the reconstructed images. Alternative Names:
Nuclear magnetic resonance - chest; Magnetic resonance imaging - chest; NMR - chest; MRI of the thorax How the test is performed:
Since MRI makes use of radio waves very close in frequency to those of ordinary FM radio stations, the scanner must be located within a specially shielded room to avoid outside interference. The patient will be asked to lie on a narrow table that slides into a large, tunnel-like tube within the scanner. If contrast dye is used, it will be injected into a small vein of the hand or forearm. A technologist will operate the machine and observe you during the entire study from an adjacent room.
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