Diagnostic imaging modalities in head and neck disease

Abstract

Background: Because of the complex anatomy of the head and neck region, conventional projection radiography alone is unreliable and carries a high risk of misdiagnosis. The poor risk-benefit ratio of conventional radiography has led to their replacement by tomographic imaging for nearly all studies in this region.

Method: This review is based on pertinent articles retrieved by a selective search in the PubMed database (January 1980 to May 2013) as well as on the relevant guidelines from Germany and abroad.

Results: The indication for diagnostic imaging in the anatomically complex head and neck region should be established for a specific type of imaging study on the basis of a thorough clinical examination. Conventional films, though easy to obtain, often cannot answer the diagnostic question and may yield confusing information leading to misdiagnosis. Computed tomography (CT) has the best risk-benefit profile and a high diagnostic value, but low-dose protocols have not yet been put into use in all centers. Magnetic resonance imaging (MRI) is best for bone and soft-tissue diagnosis, but consumes more resources. Digital volume tomography (DVT) is another type of three-dimensional, sectional imaging with high local resolution; the associated radiation exposure and image quality are generally both low, but may vary depending on the apparatus used. DVT cannot be used to evaluate the soft tissues. Ultrasonography can be used to evaluate superficial structures in the head and neck region; nuclear imaging can be used to evaluate thyroid disease and cancer.

Conclusion: Inflammatory, traumatic, and neoplastic diseases of the head and neck are best evaluated with cross-sectional imaging (CT, MRI) in accordance with current guidelines. Conventional x-rays should, in general, only be used for dental evaluation, with rare exceptions.

Figure 1

Imaging of the paranasal sinuses. a) A conventional occipitomental x-ray. b) An axial CT obtained shortly after the image in a), clearly revealing an opacification in the sphenoid sinus (arrow). The plain film is falsely negative despite its good technical quality

Figure 2

Imaging of the petrous bone. a) Schüller view. b) Axial CT. The preoperative x-ray, taken because of a clinical suspicion of mastoiditis, revealed nothing more than a low degree of pneumatization of the temporal bone. Intraoperatively, when the surgeon began to drill the mastoid bone, a pulsating, blue structure was seen, and the operation was terminated. A CT obtained thereupon to clarify the situation revealed, as a normal variant, a strongly lateralized sigmoid sinus (star) with an iatrogenic (post-surgical) bony dehiscence (arrow). This surgically relevant anatomical variant was not recognizable on the plain film, even retrospectively