The Application Value Of Post-processing Technique Of Multiple Slice Spiral CT In Orbit Fracture

Objective:X-rays and conventional CT can not display accurately orbital fracture because of their very complicated osteal structure, It is difficulty to diagnosis the orbital fracture, so they can be frequently misdiagnosed. With the isotropic scanning of multi-slice CT, to explore the diagnostic and clinical value of post-processing techniques of multi-slice spiral CT(MSCT) in orbit.Methods:106 cases with the source images of normal orbital were retrospectively reviewed and processed the source images using multi-planar reformation(MPR). To compare the conventional transverse images of the canal of zygomatic bone,infraorbital canal and the zygomaticofrontal suture with the reformation. Another,65 patients with orbital fractures subjected to MSCT reformatted images and CT conventional transverse images were retrospectively reviewed. They were classified into 3 grades based on the utility of the advanced MSCT reformatted images:the grade A group (substantial new information was obtained), the grade B group (confirmatory with improved visualization and understanding of the orbital fracture), and the grade C group (no added useful information was obtained).Results:â‘ The orbit and relative structures can be display symmetrically by the standard transverse and coronal section. The display rate of the canal of zygomatic bone and infraorbital canal in the standard coronal images was significantly higher than in conventional images(P<0.05);.There were no difference in the display rate of the zygomaticofrontal suture (P> 0.05).â‘¡There were 28 fractures (24 cases) in grade A, 51 fractures (32 cases) in grade B, and 106 fractures (42 cases) in grade C.106 fractures were shown by CT axial images,and 185 fractures by MSCT reformatted images.Fractures were located in the medial wall of orbit in 49 cases, in the side wall of orbit in 23 cases, in the superior wall of orbit in 13 cases, in the inferior wall of orbit in 21 cases, in the optic canal in 8 cases, in the nasolacrimal duct in 1 cases.MSCT reformatted images can clearly reveal the all fractures and obtain more useful information not presented on CT conventional transverse images.Conclusion:â‘ Multi-planar reformation (MPR) of multi-slice CT can reduce the radiation dose;â‘¡MPR can display symmetrically the orbital structure and avoid the difficulty in positioning patient;â‘¢MSCT reformatted images can clearly reveal the whole and detail the osteoporosis structure of the orbital fracture and obtain more useful information not presented on CT conventional transverse images.