J Korean Radiol Soc.
1994 Nov;31(5):813-818.
Temporal Bone Trauma: Correlative Study between CT Findings and Clinical IVlanifestations
Abstract
- PURPOSE
To assess how accurately computed tomography (CY) can demonstrate the abnormal findings
which are believed to cause the clinical signs and symptoms of hearing loss (HL), vertigo and facial paralysis
(FP) in patients with temporal bone trauma.
MATERIALS AND METHODS
The authors studied CT scans of 39 ears in 35 patients with temporal bone
trauma. CT scans were performed with 1-115 mm slice thickness and table incrementation. Both axial and
coronal scans were obtained in 32 patients and in three patients only axial scans were obtained. We analyzed CT
with special reference to the structural abnormalities of the external auditory canal, middle ear cavity, bony
labyrinth, and facial nerve canal, and correlated these findings with the actual clinical signs and symptoms. As to
hearing loss, we evaluated 32 ears in which pure tone audiometry or brainstem evoked response audiometry
had been performed.
RESULTS
With respect to the specific types of HL, CT accurately showed the abnormalities in 84% (16/19) in
conductive HL, 100% (2/2) in sensorineural HL, and 25% (2/8) for mixed HL. When we categorized HL simply as
conductive and sensorineural, assuming that mixed be the result of combined conductive and sensorineural HL,
CT demonstrated the abnormalities in 89% (24/27) for conductive HL and 50% (5/10) for sensorineural HL.
Concerning vertigo and FP, CT demonstrated abonormalities in 67%(4/6), and 29% (4/14), respectively.
CONCLUSION
Except for conductive HL, CT seems to have a variable degree of limitation for the
demonstration of the structural abnormalities resulting sensorineural HL, vertigo or facial paralysis. It is imperative to
correlate the CT findings with the signs and symptoms in those clinical settings.