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

Objective:Nasal bone fractures are common in maxillofacial trauma, diagnosis of nasal bone fracture in the past rely on X-ray or conventional CT, X-ray film can detect the majority of nasal bone fracture, but the common X-ray examination can be affected by the position of projection, the parts overlap and poor density resolution and sometimes the nasal bone fracture is easily missed; conventional CT axial or coronal examination, often difficult to make the bilateral structural symmetry, restricted by patients with trauma intolerable to the coronal scan, another by the thick limit, easy to misdiagnosis the normal structure of the fracture or fracture missed, delay in the treatment of patients or forensic confusing. Using the isotropic scanning of multi-slice CT to explore the clinical value of multislice CT post-processing technology in the nasal bone fracture.Method:MPR and VR post-process of CT original images of115patients with nasal trauma were done, nasal bone fracture was divided into Simplex Ⅰ (fracture line without displacement), Simplex Ⅱ (fracture line with displacement), comminuted fracture (simplex or bilateral nasal bone broke into3pieces or more, namely2or more through fracture lines), compound fracture (nasal bone fracture with fracture around), suture separation (suture was over2mm or dislocation of suture), in addition, simplex nasolacrimal duct fracture and nasomaxillary fracture were also included into statistics.,Considering the nasal trauma often of or associated with the maxillary frontal process fracture.83cases of normal nasal (accept the paranasal sinuses CT scan)with the source images of normal nasal were retrospectively reviewed and processed using soft tissue algorithm and high resolution algorithm MPR and VR post-processing, to display normal nasal bone suture,nasal foramen and the nasal bone morphology, score the realistic degree as well.Result:91patients with nasal trauma.9cases of Simplex Ⅰ;6cases of Simplex Ⅱ;5cases of comminuted fracture;57cases of compound fracture, in which there were32cases with orbital bone fracture,9cases of nasal septum fracture,8cases of nasolacrimal duct fracture,44cases of nasomaxillary fracture;23cases of suture separation, in which there were1case of nasofrontal suture separation and22case of nasomaxillary suture;11cases of simplex nasomaxillary fracture;2cases of fracture with damage to nasal foramina,3case of fracture with damage to root foramina of nasomaxillary;1cases of fracture with damage to ocular muscle,1cases of fracture with retrobulbar hemorrhage.The rating of excellent according to the the soft tissue algorithm and high resolution algorithm VR images displaying internasal suture, nasofrontal suture,nasomaxillary suture and nasal foramen were47.0%vs0%;91.6%vs9.6%;72.3%vsl2.0%;84.3%vs3.6%.35cases were common type, nasal tip is straight;48cases varied, divided into four types:unilateral inverted"V"16cases、 bilateral "M"29cases、crack-like2cases and Sawtooth-like1case.Conclusion:MPR images combined with High resolution algorithm VR images display the normal nasal bone structure, variation, and multiple fractures of great value, especially beneficial to distinguish between nasal foramen, the suture, the nasal bone variation and no significant displacement of the linear fracture, making diagnosis more accurate, perfect, and provide a better basis for treatment.