低剂量扫描技术在三维CT测量DDH股骨颈前倾角中的临床应用研究

The Clinic Study of the 3DCT with Lowdose Scanning in Measurement of Femoral Neck Anteversion of Developmental Dysplasia of the Hip(DDH)

目的探讨低剂量扫描技术在三维CT测量DDH股骨颈前倾角中的应用。方法选择不同的扫描参数对DDH患儿进行扫描,120kV保持不变,mAs选择200mAs-25mAs,层厚选择4mm,螺距选择3.0-5.0mm,对于不同扫描参数进行5组匹配,记录CT剂量指数,评价图像质量。结果在选择的五组扫描参数中,CT剂量指数分别为25.7±0.5、16.6±0.6、3.5±0.7、3.2±0.7、2.8±0.8,图像质量为优、良、中、中、差,前四组的图像能够满足股骨颈前倾角的测量。结论在满足临床诊断的情况下,低剂量扫描有效地降低了DDH患儿的辐射剂量,更加符合防护原则。

Objective To evaluate the application value of 3DCT with low dose scanning for femoral neck anteversion of developmental dysplasia of the hip （DDH）. Methods The DDH children were scanned by using different scan parameters, keeping 120kV while setting mAs from 200-25mAs, thickness 4mm, Pitch 3.0-5.0mm and then matched 5 different groups of parameters. CT dose parameters were recorded and image qualities evaluated. Results In the 5 selected groups of scan parameters , CT dose parameters were 25.7±0.5、16.6±0.6、3.5±0.7、3.2±0.7 and 2.8±0.8, image qualities were excellent, good, moderate ,moderate and bad respectively. Except for the last group, the other 4 groups can meet the requirement of measuring femoral neck anteversion. Conclusion Low-dose 3DCT scanning can effectively reduce the radiation dosage, which better meets the demand of the radiation protection principle.