MRI Head & Neck

RI Eye Ear Head and Neck

MRI is very useful in the head and neck area, particularly for its ability to discriminate variations in soft tissue. 
However, it will not delineate bony erosion and a CT may be necessary for evaluation for bone adjacent to a lesion. A CT is also more advantageous in imaging the paranasal sinus,as any inflammation of mucosa or thickened secretions will appear as an area of high signal intensity on MRI. 
MIR can also be used to evaluate blood flow. Flow can be detected and mapped by MR and magnetic resonance angiography is, in many cases, replacing traditional angiography. 
In general, MRI is most often utilized as the primary imaging modality when evaluating tumor spread in the paranasal sinuses, cavernous sinuses, dura, brain, nasopharynx, oropharynx, palate, base of tongue, and floor of mouth. That is, the closer to the skull base, MRI offers more advantages over CT. 
MRI is also the modality of choice for evaluating perineural tumor spread. 
The detection of retropharyngeal adenopathy also remains almost solely in the realm of CT and MRI and the presence of such nodal metastasis requires modification of both surgical and radiation fields. 
It is also estimated that about 5% of clinically silent metastatic nodes will be identified on CT and MRI and thus the most thorough assessment of the neck is by combined clinical and imaging evaluation. Imaging also best demonstrates extranodal (extracapsular) tumor extension and if that disease has involved the great vessels or bone. 
MRI would be better than CT if cavernous sinus thrombosis is considered.

 
       

Lesions are well visualized with MRI :

  • Tongue
  • Oropharynx
  • Nasopharynx
  • Trachea
  • Thyroid
  • Parathyroid
  • Salivary glands
  • Abnormalities of the throat,
  • Inner ear
  • Eyes
  • Temporomandibular joint
  • Cerebellar pontine angle
 
        

MRI has been used for the neoplastic diseases for:

  • Diagnosis
  • Staging
  • Pre-operative evaluation
  • Evaluation for response to treatment
  • Follow-up
  • Restaging
  • Treatment planning for radiation therapy
  • Treatment planning for palliation therapy
 
       

MRI of the Head and Neck is considered medically necessary when history or current clinical status meets any of the following criteria:

  • Undiagnosed mass on exam or other imaging studies.
  • Congenital Anomaly requiring treatment.
  • Suspected Wegner’s Granulomatosis.
  • Anosmia.
  • Recurrent epistaxis.
  • Abnormalities noted on other imaging or endoscopic studies which require additional clarification.
  • MRI allows an estimate of tumor spread into surrounding soft-tissue areas, such as the anterior cranial fossa and the retro maxillary space.
  • The MRI is indicated for sudden or progressive proptosis and sudden vision loss in the adult.
  • Known malignancy for diagnosis, staging or evaluation for response to treatment or pre-operative evaluation.
  • Planned treatment for radiation therapy.
  • Unexplained Hearing loss.
  • Significant tinnitus or vertigo.
  • Suspected acoustic neuroma or other tumor or preoperative treatment of acoustic neuroma or other tumor.
  • Significant infection unresponsive to medical treatment, suspected abscess, mastoiditis.
  • Cholesteotoma.
  • MRI better for sensirineural hearing loss.
  • Some indications may require studies of the temporal bone with specific attention to internal auditory canal.
  • MRI is preferred for evaluation of fibrous ankylosis, arthritides, inflammatory conditions and disk position of Temporomandibular Joint (TMJ) .
  • MRI can assess the extent of tracheal compression by a thyroid nodule or goiter.
  • MRI of the orbits is obtained for a variety of reasons, and is the most accurate method in evaluating for pathology behind the orbits (retro-orbital), involving the optic nerves, chiasm, and optic tracts.
    • Some of the most common reasons why we look at the orbits include:
    • Visual changes and possible optic nerve involvement in patients suspected of having multiple sclerosis,
    • proptosis of the globe (protrusion) and suspicion of a retro-orbital mass, and
    • patients with glaucoma.
  • Less often in a patient who is difficult to examine clinically, imaging can demonstrated areas of the pharynx, larynx, and trachea that are not possible to a ssess directly or can not be visualized well enough by direct observation to confidently rule out pathology.