LCD L34425: Magnetic Resonance Imaging of the Head and Neck

Magnetic resonance imaging (MRI) is a radiation-free, noninvasive technique used to produce high-quality sectional images of the inside of the body in multiple planes. MRI uses natural magnetic properties of the hydrogen atoms in the body that emit radiofrequency signals when exposed to radio waves within a strong magnetic field. These signals are processed and converted by a computer into high-resolution, three-dimensional, tomographic images. Images and resolution produced by MRI is quite detailed. For some MRI, contrast materials (e.g., gadolinium, gadoteridol, non-ionic and low-osmolar contrast media, ionic and high-osmolar contrast media) are used to enable visualization of a body system or body structure. 1

MRI provides superior tissue contrast when compared to a computerized tomography (CT) scan, can image in multiple planes, is not affected by bone artifact, provides vascular imaging capability, and makes use of safer contrast media (gadolinium chelate agents). 1 Its major disadvantage over a CT scan is the longer scanning time required for study, making it less useful for emergency evaluations. Contraindications include patients with implanted neurostimulators or cochlear implants. Potential contraindications may include patients with cardiac pacemakers (refer to the CMS Internet-Only Manual, Pub. 100-03, Medicare National Coverage Determinations (NCD) Manual, Chapter 1, Part 4, §220.2), metal fragments in the eye, magnetic ocular implants or patients with older ferromagnetic intracranial aneurysm clips. All these objects may be potentially displaced when exposed to the powerful magnetic fields used in MRI.

MRI of the orbit, face and/or neck may be considered medically reasonable and necessary when used to diagnose and characterize pathology of the eye, nasopharynx, oropharynx, and neck including tumors, infection, soft tissue pathologies, and congenital abnormalities. In cases involving trauma to the orbit, face and/or neck, a CT scan is frequently superior to MRI for assessing injury.

In many instances, ordering an MRI of the brain, in addition to an MRI of the orbit, face and/or neck, may be medically necessary on the same day. The medical record should document the medical necessity for these 2 procedures being performed on the same day.

A literature review was conducted to highlight some of the areas where MRI of the orbit, face and neck was used to demonstrate the utility of this imaging modality. Sources include published peer-reviewed articles and published society guidelines from the last 25 years.

MRI is superior for the evaluation of the visual pathways, globe and soft tissues; CT is preferred for visualizing bony detail and calcifications. 2,3

Orbital MRI may be used for abnormalities detected on external or direct eye examinations, optic neuritis, orbital trauma, ocular mass(es), known or suspected orbital infection, osteomyelitis, congenital anomalies and strabismus concerns. 4-25

Sinus MRI may be required to detect abnormalities and conditions such as rhinosinusitis with suspicion of fungal infections, clinical suspicion of orbital or intracranial complications, suspected mass based upon exam, nasal endoscopy or previous imaging and for conditions such as anosmia or osteomyelitis. 20,21,26-31