“Certain tumors almost never metastasize to the brain parenchyma. Non-covered indications: esophagus, oropharynx, and prostate, and non-melanoma skin cancer in the absence of symptoms of brain involvement. Clinicians commonly use CT and MRI of the brain when metastatic involvement is suspected. The information provided by the two modalities may be complementary.Ĭancer Staging. Inconclusive findings on a CT scan may warrant a MRI study and, conversely, findings of a MRI study may be further clarified (under certain circumstances) with a subsequent CT scan. Medicare coverage for CT scans is allowed provided the service is medically reasonable and necessary. Such units must be operated within the parameters specified by the approval. See national non-coverage in CMS section above.Ĭoverage is limited to those CT and MRI machines that have received pre-market approval by the FDA. Reconstructed images can be displayed in multiple planes to facilitate analysis. Fluctuations in the strength of the magnetic field alter the motion and relaxation times of hydrogen molecules, which are related to the density of molecules and reflect the physicochemical properties of the tissues. Magnetic Resonance Imaging (MRI) is a non-invasive diagnostic scanning technique that employs a powerful and highly uniform static magnetic field, rather than ionizing radiation, to produce images. The signal data may be subjected to a variety of post-acquisitional processing algorithms to obtain a multiplanar view of the anatomy. Computers process the signals to produce a cross-sectional view of the body. As x-rays pass through planes of the body, the photons are detected and recorded as they exit from different angles. Setting & Population:ħ0486 – Computed tomography, maxillofacial area without contrast materialħ2125 – Computed tomography, cervical spine without contrast materialĬoverage Indications, Limitations, and/or Medical NecessityĬomputerized tomography (CT scanning) uses the attenuation of an x-ray beam by an object in its path to create cross-sectional images. 72156 Magnetic resonance imaging, spinal canal and contents, without contrast material, followed by contrast material(s) and further sequences, cervical.72142 Magnetic resonance imaging, spinal canal and contents, cervical with contrast material(s).72141 Magnetic resonance imaging, spinal canal and contents, cervical without contrast material.
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