颌面部骨折的CT三维表面成像及容积成像对比研究

Comparetive analysis of 3D surface shading display and volume rendering in maxillofaicial fracture

目的 观察比较螺旋CT三维表面成像 (surfaceshadingdisplay ,SSD)和容积成像(volumetricredering ,VR)显示颌面部骨折的效果 ,探讨二者的成像技术以及临床应用价值。方法 对32例外伤致颌面部骨折病人进行轴面容积扫描 ,其中 5例经钛合金复位复查 ,然后在工作站进行三维SSD和VR成像 ,立体显示颌面骨 ,结合二维图像比较二者在显示骨折线、移位旋转、塌陷程度以及总体空间表达的效果。结果 32例中SSD显示骨折 2 8例 ,8例未能完全显示全部骨折线 ,4例阴性 ;VR显示了 32例的全部骨折。SSD显示骨折立体效果优于VR ,对明显移位旋转的骨折显示清晰。VR在显示骨折细微结构和无移位骨折明显优于SSD ,对钛合金固定复位疗效明确 ,对颅底、筛窦等立体效果稍逊于SSD。结论 SSD和VR成像对颌面部骨折可互为补充 ,立体直观、完整地显示颌面部骨折的病理解剖关系 。

Objective To compare SSD with VR techniques in clinical application of maxilloficial fracture. Methods 32 patients with trauma of maxilloficial bone were scanned with 3 mm colimation,reconstruction interval 1 mm and pitch of 1.5, of which 5 cases were reexamined after fixation with titanium alloy. Original data obtained with transaxial images were transferred to workstation and processed with SSD and VR. The images generated by both techniques were compared for fracture line,fragment displacement,collapse degree and space information and in conjunction with 2D images. Results Fractures in 28 cases of 32 patients were shown with SSD, 8 were not fully displayed, 4 negative. VR depicted all fractures showed with 2D images. SSD was superior to VR in displaying spatial relationship of fracture in patients with evident fragment displacement, especially base of skull ethmoid sinus,processus pterygoideus,ect. But VR was more accurate in showing tiny small fracture and detailed structure, and could pick up fractures without displacement and overlooked by SSD. VR discriminated metal from tissues more clearly than SSD. Conclusion 3D images with SSD and VR present a direct visulisation of maxilloficial fractures.Combination of both techniques provides an advantage of showing pathologico anatomic relationship of maxilloficial fractures more accurately and stereoscopically, and has an important value in diagnosis and assessing the effect of reduction.