摘要
目的探讨胸部螺旋CT最大密度投影(MIP)重建合理的扫描和重建参数。方法6例煤工的尸检离体肺脏制成充气固定肺标本,分别行不同参数组合的螺旋CT扫描,包括层厚1.5mm,2mm,4mm及8mm,重建间隔1mm,3mm,5mm;曝光量150mA,100mA;螺距1.5;滤过算法包括标准、锐利和平滑3种。每组图像均行MIP重建,重建厚度为12.5mm～13mm,比较不同参数MIP重建图像对支气管血管束的显示。结果a)曝光量对MIP重建图像的影响甚微,150mA、100mA两组剂量MIP无显著性差异(P>0.05);b)重建算法对MIP重建无显著影响。c)扫描层厚影响MIP图像,以薄层(1.5mm)扫描重建为最佳,1.5mm、2mm、4mm层厚MIP图像之间无显著性差异(P>0.05),8mm层厚与前4者MIP图像有显著性差异(P<0.01)。d)重建间隔影响MIP重建效果,8mm层厚扫描,1mm和5mm重建间隔重建图像MIP之间有显著性差异(P<0.05)。结论影响MIP重建的参数主要为扫描层厚和重建间隔,薄层扫描可获得理想的MIP图像,随层厚的增加,减小重建间隔有利于获得理想的MIP图像。建议以中等层厚(4mm)扫描,小重建间隔(1.5mm,2mm)行MIP重建。
Objective To optimize the scan and the reconstruction parameters of maximum intensity projection (MIP) reconstructions in lung spiral CT. Methods A study of different scan parameters sets was undertaken in 6 inflated and fixed lung specimens of coal pneumoconiosis, which included slice thickness at 1.5 mm, 2 mm, 4 mm and 8 mm; reconstruction intervals at 1 mm、3 mm、5 mm; exposure dosage at 150 mA and 100 mA; pitch at 1.5; reconstructive methods comprising standard, sharp and smooth filter. MIP reconstructions were undertaken for all different parameters sets. Reconstructions thickness was 12.5 mm～13 mm. Comparing the show of pulmonary bronchus vessel bundles in MIP reconstructions. Results (1) The exposure dosage had little influence on MIP. There was no difference between 150 mA and 100 mA(P >0.05). (2) The filter had no notable influence on MIP. (3) The slice thickness had influence on MIP. The thin slice thickness (1.5 mm) was the best among different slice thickness. There were not marked difference among 1.5 mm、2 mm、4 mm(P >0.05). There was marked difference between 8 mm and 1.5 mm、2 mm、4 mm(P< 0.01). (4) Reconstruction intervals had effects on MIP. For 8 mm slice thickness, there was marked difference between 1 mm reconstruction intervals MIP and 5 mm reconstruction intervals MIP(P< 0.05). Conclusion The main scan parameter that influenced MIP was slice thickness and reconstruction intervals. Thin slice thickness could help to obtain optimal MIP. With increasing of slice thickness, thin reconstruction interval could conduce to obtain optimal MIP. We suggest that middling slice thickness(4 mm)and thin reconstruction interval(1.5 mm、2 mm)should be applied for MIP reconstructions.
出处
《实用医学影像杂志》
2004年第3期141-143,共3页
Journal of Practical Medical Imaging
关键词
肺
最大密度投影
计算机体层摄影
图像处理
计算机辅助
Lung
Maximum intensity projection (MIP)
Computed tomography (CT)
Image processing
Computer assisted
