role of routine nonenhanced head computed tomography scan in excluding orbital, maxillary, or...

Role of routine nonenhanced head computed tomography scanin excluding orbital, maxillary, or zygomatic fractures secondaryto blunt head trauma9100047劉芳君

The purpose ,determine the necessity of a dedicated facial bone/orb(CT) ,fracture surveillance ,blunt head trauma

routine nonenhanced head CT scan is negative.

A positive head CT scan :an air–fluid level paranasal sinuses ,maxillary, orbital, zygo

matic osseous structures. Intracranial/parenchymal pathology was n

ot evaluated in this way.

Method

these 65 patients, none subsequently had a positive facial bone or orbit CT scan.

The sensitivity are100%.

a negative nonenhanced head CT scan precludes the need for dedicated facial bone ,orbital CT scan

unnecessary radiation exposure, health

care costs, and time

The ‘‘clear sinus sign’’ the paranasal sinus walls results in hemor

rhage.

not associated with paranasal sinus fluid.

saves patient unneeded time in the Emergency Department,

saves them from potentially harmful radiation

saves healthcare dollars.

Materials and methods

The avera patient age was 44.5 years, and 59% of the patients were male.

Nasal bone fractures were noted incidentally study.

No evaluation was made regarding intracranial/parenchymal pathology.

Fig. 1 Scout image from routine noncontrast head CT scan

demonstrating image acquisition protocol

Table 1 Correlation of imaging results

Head CT+ Head CT+ Totals

Facial bone/orbit CT + 42 0 42

Facial bone/orbit CT - 8 65 73

Totals 50 65 115

Eight patients with a positive nonenhanced head CT

scan subsequently had a negative facial bone/orbit CT.

These patients were found to have free fluid within a paranasal sinus on the head CT scan.

Etiologically this fluid was determined to be secondary to an isolated nasal bone fracture (in five cases) or an inflammatory

process.

Discussion

scan was defined as showing either an air–fluid level in a paranasal

A positive head CT sinus or evidence for a maxillary, orbit, or zygom

atic fracture.

The free fluid within the sinus results from injury to the lining of the paranasal sinuses. This

mucoperiosteu contains a very rich vascular

Axial scans through the zygoma are quite sensitive for a displaced fracture

Nasal bone fractures are often clinically evident and can be confirmed with plain film radiography

Fig. 3 Direct coronal image verifies fractures of the inferior rightorbit and lateral wall of the right maxillary sinus

Fig. 4 Axial CT image reveals minimally displaced fracture of theleft zygomatic process

Fig. 5 Plain film image demonstrates a nasal bone fracture