CRANIOFACIAL TRAUMA Flashcards
initial imaging modality of choiceas it is widely available, fast, and very sensitive for detecting abnormalities that would require emergent neurosurgical attention, namely acute intracranial hemorrhage, herniation, and hydrocephalus.
Noncontrast multidetector CT (MDCT)
excels in the detection of skull fractures and radiopaque foreign bodies (e.g., bullet
fragments)
Noncontrast multidetector CT (MDCT)
more sensitive to brainstem injury and to subacute and chronic hemorrhage, especially with fluidattenuated inversion recovery (FLAIR), gradient-recalled echo (GRE) T2*-weighted, and susceptibility-weighted
imaging (SWI)
MR
superior to CT in the detection of acute epidural and subdural hematomas and nonhemorrhagic brain injury
MRI
particularly sensitive to blood products and can often identify small areas of
hemorrhage undetectable on GRE sequences or even CT.
SWI
improved detection of both acute and chronic neuronal injury
Diffusion-weighted and diffusion tensor imaging
modality
of choice for patients with subacute and chronic head injury and is recommended for patients with acute head trauma when neurologic findings are unexplained by CT
MRI
more accurate in predicting long-term
prognosis.
MRI
most common type of skull fracture
Nondisplaced linear fractures of the calvarium
Pneumolabyrinth. Axial bone window CT image at the level of the right otic capsule shows abnormal gas within
the right vestibular apparatus compatible with pneumolabyrinth (straight arrow). There is also a minimally displaced fracture of
the right squamous temporal bone (curved arrow).
may present with deafness, facial nerve palsies, vertigo, dizziness, or nystagmus.
Patients with fractures of the temporal bone
Physical signs of temporal bone fracture
hemotympanum, CSF otorrhea, and
ecchymosis over the mastoid process (“Battle sign”)
opacification of the mastoid air cells,
fluid in the middle ear cavity, pneumocephalus, or occasionally, pneumolabyrinth
should raise the suspicion of a temporal bone fracture
- Temporal bone fracture parallels the long axis of the petrous pyramid.
- Represents 70% to 90% of temporal bone fractures
- results from a blow to the side of the head
- Complications include conductive hearing loss, dislocation or fracture of the ossicles and CSF otorhinorrhea. Facial nerve palsy may occur, but it is often delayed and incomplete. Sensorineural hearing loss is uncommon.
“longitudinal” temporal bone fracture
- Temporal bone fractures perpendicular to the long axis of the petrous bone
- usually results from a blow to the occiput or frontal region
- Complications are usually more severe and include sensorineural hearing loss, severe vertigo, nystagmus, and perilymphatic fistula.
- Facial palsy is seen in 30% to 50% of these cases and is often complete
- may also involve the carotid canal or jugular foramen, causing injury to the carotid artery or jugular vein.
“transverse” temporal bone fractures
Longitudinal Temporal Bone Fracture. Longitudinal right temporal bone fracture is detected on noncontrast CT (A, white arrow). There is associated hemorrhage in the right mastoid air cells and middle ear cavity. High-resolution reformats of the temporal bones were then obtained, which demonstrate mild right malleo-incal dislocation (B, black arrow) when
compared to the normal malleo-incal relationship on the left (C, black arrow). This fracture spares the otic capsule.
Ossicular Dislocation. Axial high-resolution CT images through the bilateral temporal bones reveal more pronounced left malleo-incal dislocation (arrow, B). Normal right ossicular alignment is shown on the right for comparison (A)
Otic Capsule Violating Temporal Bone Fracture. Axial CT images through the right temporal bone demonstrate a comminuted transverse fracture violating the otic capsules. (A) A fracture line (black arrow) is noted extending from the
vestibule posteriorly into the posterior fossa intracranial cavity. (B) A slightly more superior image on the right reveals extension into the middle cranial fossa as well. There is also fluid in the middle ear cavity and mastoid air cells. The head of the malleolus is visualized but is not associated with the incus.
