Halo sign
| Halo sign | |
|---|---|
| Differential diagnosis | temporal arteritis |
In
MRI show promise for replacing it.[2]
The halo sign of temporal arteritis should not be confused with Deuel's halo sign, which is a sign of fetal death.[3]
The halo sign is also understood as a region of ground-glass attenuation surrounding a pulmonary nodule on an
pulmonary infection by the fungus species Aspergillus
.
In nursing, the halo sign is the result of a test to see if drainage from a head injury contains cerebrospinal fluid. When a Dextrostix or Tes-Tape test gives a positive reading for glucose, the drainage must be further tested because glucose is also found in the blood. To perform the test, the leaking fluid is dripped onto a 4x4 gauze or towel. Positive results are indicated by blood coalescing into the center, leaving an outer ring of cerebrospinal fluid.