Purpose: The aim of the study was to compare the sonographic and CT classifications of the type of nasal fractures.

Materials and methods: 72 patients with nasal trauma were investigated. All patients underwent US (5--12 MHz linear array transducer) and axial CT scans. The fractures classifications by US findings were compared with the classifications by CT findings.
Nasal fractures were classified into the followings.
Type 1: no fracture or fracture without displacement.
Type 2: fracture with unilateral displacement / without posterior displacement.
Type 3: fracture with bilateral displacement / without posterior displacement.
Type 4: fracture with posterior displacement / without lateral displacement.
Type 5: fracture with bilateral and posterior displacement.
The ?2 test and κ values were used to compare the results between the 2 diagnostic tools (US and CT).

Results: The nasal bone fractures classified by CT findings were type 1(31 cases, 43%), type 2(19 cases, 26%), type 3(14 cases, 19%), type 4(5 cases, 6% ), type 5(3 cases, 4%) and by US findings were type 1(22 cases, 30%), type 2(27 cases, 37%), type 3(11 cases, 15%), type 4(6 cases, 8%), type 5(6 cases, 8%). The κ test showed a good correspondence between 2 diagnostic tools (κ =0.563).
The ?2 test showed no statistical significant difference was found between US and CT in the classifications of the nasal bone fracture (p=0.358).

Conclusion: Ultrasonic investigation of the nasal bone is a useful way to classify the fracture types that provides similar results to CT.