Imaging Studies
After a comprehensive history and physical examination, the most important test for determining structural involvement and subsequent management is a non-contrast computed tomography (CT) scan of the head and facial bones. Various windows are available through CT imaging (osseous, soft tissue, heme windows), making evaluation of these and related injuries rapid and reliable. [3]
If a frontal sinus fracture is observed on CT, this indicates significant trauma, and it is imperative to search for corresponding injuries. [3] Examine bone windows to evaluate the posterior table of the frontal sinus.
Obtain routine facial views, including Waters, Caldwell, and lateral projections. The Caldwell projection provides the best view of the anterior table; however, the posterior table is difficult to assess on any of the standard plain film views. If CT is available and is performed, no evidence suggests any additional benefit to be derived from plain film radiography. [3]
Consider angiography if the physician is concerned about possible vascular injury. [3]
Use ultrasonography to detect fractures by using a linear probe in a superficial mode. This test should be viewed as an adjunct to the previously mentioned modalities. [3]
Look for associated orbital rim and naso-ethmoidal fractures on CT scan.
Consider brain CT scan to exclude brain injury or an intracranial bleed.
Other Tests
Lab studies include direct lab studies toward workup of a trauma patient. If fracture is an isolated injury, obtain preoperative labs if surgery is planned.
Test clear rhinorrhea for glucose to help determine if it is CSF, as nasal secretions are normally low in glucose. If blood is present, this test is unreliable.
Blood-tinged fluid can be placed on filter paper to look for a double-ring sign of CSF around the blood; however, this technique is not reliable.
When dural leak causing CSF rhinorrhea is suspected yet cannot be proven, the following procedure, which generally is not performed in the ED, may be done: Inject fluorescein dye into the lumbar subarachnoid space. Examine the discharged nasal fluid 30 minutes later with a Wood lamp for fluorescence; fluorescence confirms CSF rhinorrhea.
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Anterior and lateral views of the frontal sinus. These figures demonstrate the relative thickness of the anterior and posterior tables, as well as the relationship of the frontal sinus to the orbits, ethmoid sinuses, and anterior cranial fossa.
