Nasopharyngeal carcinoma MRI
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Nasopharyngeal carcinoma Microchapters |
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Differentiating Nasopharyngeal carcinoma from other Diseases |
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Diagnosis |
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Treatment |
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Case Studies |
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Nasopharyngeal carcinoma MRI On the Web |
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American Roentgen Ray Society Images of Nasopharyngeal carcinoma MRI |
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Risk calculators and risk factors for Nasopharyngeal carcinoma MRI |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Faizan Sheraz, M.D. [2]
Overview
Head and neck MRI may be helpful in the diagnosis of nasopharyngeal carcinoma. Findings on MRI suggestive of nasopharyngeal carcinoma include dural thickening and bone marrow infiltration.
MRI
MRI may be diagnostic of nasopharyngeal carcinoma. Findings on MRI scan suggestive of nasopharyngeal carcinoma include:[1]
The protocol for routine MRI of a nasopharyngeal mass includes unenhanced T1- weighted images to detect skull base involvement and fat planes (in at least an axial and sagittal plane). A T2-weighted fast spin-echo sequence in axial plane is used for the additional assessment of early parapharyngeal tumor spread, paranasal sinus invasion, middle ear effusions, and detection of cervical lymph nodes. Axial and coronal contrast-enhanced T1-weighted images (with and without fat suppression) are used to detect tumor extent, including perineural spread and intracranial extension of the tumor. The slice thickness is 3–5 mm . Additional MRI sequences may be used in evaluation of NPC but, at present, are of limited proven clinical value, although whole body MRI for metastatic deposits of NPC are promising . Other reported MRI techniques include diffusion-weighted imaging, to aid in differentiating NPC from lymphoma and characterizing of cervical lymphadenopathy , and MRI spectroscopy, where choline-to-creatine ratios for the NPC and metastatic nodes are high compared with those for normal neck muscle .
MRI is an accurate test for the diagnosis of NPC. MRI depicts subclinical cancers missed at endoscopy and endoscopic biopsy and identifies patients who do not have NPC and who therefore do not need to undergo invasive sampling biopsies . NPCs usually present with intermediate signal intensity, higher than the muscle signal, on T2-weighted images, low signal intensity on T1- weighted images, and enhance to a lesser degree than does normal mucosa. Eighty-two percent of NPCs arise in the posterolateral recess of the pharyngeal wall (Rosenmüller fossa), and 12% arise in the midline. In 6–10% of patients, the nasopharyngeal mucosa appears normal at endoscopy.
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