螺旋CT三维容积重建的临床应用

Clinical application of VR three dimensional reconstruction by spiral CT

目的 :探讨螺旋CT三维容积重建(VR)成像方法 ,评价其临床运用范围与价值。材料及方法 :VR三维重建47例 ,包括 :①血管组19例 ,②骨关节组16例 ,③其它部位组12例。扫描技术及造影剂使用参数据部位及病变性质具体设置 ,同时比较VR与表面遮盖法(SSD)及最大强度投影(MIP)。结果 :选择2或3个目标、合适的衰减值及不透明度的限值可获得良好的VR立体成像。VR能显示血管管腔、血管之间、血管与周围器官的相互关系 ,以及显示椎间盘、脑室、支气管等结构或其病变。SSD及MIP显示血管呈实性 ,周围结构相互阻挡 ,对椎间盘、脑室、支气管或其病变显示不佳。血管组病变13例包括血管动静脉畸形6例 ,血管栓塞、血管受脑膜瘤推压侵犯各2例 ,颈静脉球高位、烟雾病、胃底静脉曲张各1例 ;骨关节组病变14例 :颅底骨折8例 ,关节面骨折、关节脱位、椎间盘脱出各2例 ;其它部位组病变7例 :脑积水2例、支气管肺癌、恶性胃溃疡、肾外肾盂、输尿管结石、脑血肿各1例。结论 :VR -3D血管造影是快速而有效的无创伤血管成像术 ,优于SSD及MIP ,其中动静脉畸形、脑膜瘤、较大脑内血管分支阻塞可替代血管造影。骨关节显示清楚直观 ,有利于微细骨折、关节半脱位的诊断及测量 ,椎间盘、半月板显示具有独到之处。VR -3D在气管支气管、胃肠道、?

Objective:To study the ways of volume rendering(VR) three-dimensional reconstruction(3D) by spiral CT,and evaluate its clinical applications.Methods:47 cases examined by VR-3D were divided into three groups:①19 of blood vessels,②16 of osteoarticular,③12 of other parts.The scanning techniques and parameters of using contrast material varied with the parts of the lesions and scanning range,VR being compared with SSD and MIP.Results:High quality VR-3D images will be obtained by selecting 2 or 3 objects,appropriate range of attenuation value and opacity%.VR can show blood vessel cavities and the correlation among blood vessels and the organs around them.It can also show the structures and pathological changes of intervertebral disc,ventricle and bronchus.Among the 13 blood vessel diseases were 6 arteriovenous malformations,2 vessels embolism,2 vessels of being pressed and eroded by tumor,1 gastric bottom varix,1 high-level jugular glomus and 1 moyamoya.14 osteoarticular diseases included 5 cranial fossa fracture,2 articular surface fracture,2 articular dislocation,2 protrusion of intervertebral disc.Subtle fracture,articulatio atlanto-axialis dislocation,intervertebral disc and meniscus can be clearly showed,while the same good effect can not be obtained by CT crossing scan or X-ray plain.7 other part cases were 2 hydrocephalus,1 bronchial lung cancer,intracerebral hematoma and 1 malignant gastric-ulcer.They can only be showed by VR.As for the l renal pelvis outside kidney and 1 calculus of ureter.their effects are far better by VR.Conclusions:VR-3D was found to be a fast noninvasive and effective method to image complex vascular structures.It can take the place of angiography in arteriovenous malformation,meningioma and bigger intravertebral blood vessel branch embolism.Osteoarticular 3D images by VR are clear and intuitionistic enough to help diagnose and measure subtle fracture and articular part-dislocation.VR-3D has advantage over SSD and MIP in vessel,intervertebral disc and meniscus.Its applications in trachea-bronchial tree,gastrointestinal,ventricle and urethra also show great clinical value.