颌面骨螺旋CT扫描和三维重建参数的研究

通过对颅骨螺旋ＣＴ扫描和三维重建参数的选择，以获得最佳三维图像。材料与方法，采用砂颅各２个及２位正常志愿者，采用不同层厚和床速的螺旋ＣＴ扫描，并行不同间隔、不同阈值的表面阴影显示法三维重建。结论薄的层厚，重叠重建，、适当的阈值可获得最佳的颅骨三维图像。

Study on the Scanning and 3-Dimensional Reconstruction Parameters of Skull Spiral CT

Objective To obtain the best 3 D images by optimizing the scanning and reconstruction parameters of skull spiral CT.Materials and Methods Spiral CT scanning with different collimations, bed speed and pitch was performed in 2 dry skulls, 2 cadaveric heads and 2 normal volunteers. 3 D images were obtained by surface shaded display (SSD) with different thresholds, and were compared with each other.Results The comparison of 3 D images using different scanning parameters showed that the thinner the collimation was, the closer to the actual size of the skull the 3 D image would be. Higher pitches did not affect the image and, when used, collimation could be further reduced. When the lowest threshold, at which soft tissue couldn't show up, was used, and when reconstruction was done by interval which was non integer of collimation, the best quality images could be obtained.Conclusion Thinner collimation scanning, denser overlapping reconstruction and appropriate threshold are the key technical points for obtaining ideal 3 D skull images.