Clinical Application of Spiral CT to Acetabular Fracture: Surface Shaded Display (SSD) and Volume Rendering (VR) Techniques Study and Compared with Two- dimensional CT (2DCT),X-ray and MPR

Objective To evaluate the diagnostic value of three-dimensional SSD and VR techniques application to acetabular fracture.Methods 30 cases of acetabular trauma were examined with SIEMENS PLUS 4 spiral CT. These data were reconstructed in workstation with three-dimensional SSD and VR techniques, and then compared with the findings of X-ray, two-dimensional CT (2DCT) and MPR.Results For 30 cases of acetabular fractures, the fracture quantity of SSD and VRT was 158,169,while in X-ray plains,spiral CT and MPR was 133,169 and 169. Fracture detection rates of X-ray plains and SSD were 78.7% and 93.5%.The difference with spiral CT,MPR,VRT was not statistically significant of acetabular fractures. 30 cases of acetabular fractures were classified according to AO classification. MPR,3DCT had confirmed this classification, and 22 case had been identified through operation. X-ray misclassified seven cases. 3DCT might gain the most objective view of acetabular fractures. 12 cases of acetabular fracture were examined again post-operatively. Then the findings of postoperative were compared with that of pre-operative. The reconstructed images of VRT displayed the structure of acetabular fractures clearly, also showed the shape and location of the internal fixation and the effect of reposition after operation and the healing state of acetabular fractures. The images of SSD sometimes cannot tell the difference of the shape of structure of pelvis and internal fixation.Conclusion Three-dimensional SSD and VR techniques of spiral CT are effective methods in diagnosing acetabular trauma. 3DCT is an effective method in classifying acetabular fractures. And the imaging of SSD and VRT of spiral CT might provide exact guidance to formulating operative plan and choice of proper internal fixation, and is the first choice in examination of the complicated acutabular fracture. VR has the higher value in determine the location of the internal fixation and the effect of surgical reduction.