Characteristics of Imaging of High-resolution CT examination and reconstruction of quasi-sagittal images of optic canal fracture

OBJECTIVE To investigate the characteristics of imaging of CT with high-resolution CT(HRCT) examination and reconstruction of quasi-sagittal images of optic canal fracture,and evaluate the clinical value. METHODS Nineteen cases of patients with fractures of optic canal underwent thin layer (1.5mm thickness,1mm pitch) HRCT scanning in axial and coronal positions,and multiplanar reconstruction technique was used for quasi-sagittal reconstruction. And the united performances of HRCT were analyzed. RESULTS The direct sign of the optic canal fracture was the interruption of the continuity of the wall,including 5 types:depression type,line type,crusing type,embedded type and mixed type. The indirect signs were hematocele sphenoid,ethmoid hematoma,optic nerve thickening and teardrop sign. In the 19 cases (22eyes) of optic canal fracture,single-walled fractures 17 eyes (77.3%),multi-walled fractures 5 eyes (22.7%). Fractrues of 14 eyes (63.6%) were on the medial wall,fractrues of 4 eyes (18.2%) were on the lateral wall,fractrues of 6 eyes (27.3%) were on the superior wall,fractures of 3 eyes (13.6%) were on the inferior wall. CONCLUSIONS HRCT examination of the optic canal could clearly show the site of fracture and its sub-type,and quasi-sagittal reconstruction might improve the detection rate of fracture. It could provide reliable imaging basis for the clinical diagnosis and treatment selection.