利用低剂量颅骨三维CT建立虚拟三维颅骨模型的可行性

The feasibility of establishing virtual three-dimensional skull model by low dose threedimensional CT

目的探讨采用低削量颅骨三维CT成像制作虚拟颅骨缺损三维模型,定制钛网植入物的可行性及实用性方法颅骨成形术前进行颅骨三维CT检查的颅骨缺损患者64例,随机分为常规剂量A组(120kV、180 mA),低剂量B组(120kV、50 mA),低剂量C组(120kV、30mA),低剂量D组(100kV、30mA),记录容积CT剂量指数(CTDIvol)和剂量长度乘积(DLP),计算有效剂量(ED)。根据图像质量评分标准评估所有图像质量发送CT数据给重建公司制造精确的钛种植体,神经外科医生实施颅骨成形术结果常规剂量A组及低剂量B、C、D组的CTDlvol分别为24.32mGy、6.75mGy、4.05mGy、2.61mGy。DLP和ED四组比较差异有统计学意义(P<0.001)。低剂量D组DLP和ED分别比常规削量A组低89.4%和89.6%(P<0.001)。各组图像均在一般及以上等级,差异无统计学意义(P>0.05)。钛种植体成功制造,颅骨成形术顺利进行,患者临床功能恢复理想。结论颅骨缺损患者在颅骨成形术前进行低剂量颅骨三维CT扫描,制作虚拟三维模型,定制钛网植入物,不仅完全满足临床要求,而且显著减少了辐射剂量,具有较大实用价值。

Objective To explore the feasibility and practicability of making virtual 3D model of skull defect and customizing titanium mesh implantation by low dose skull 3D CT imaging.Methods 64 patients with skull defects examined by skull three-dimensional CT before cranioplasty were randomly divided into four groups:conventional dose group A(120kV,180mA),low dose group B(120kV,50mA),low dose group C(120kV,30niA),low dose group D(lOOkV,30mA).After the scanning,the volume CT dose index and dose length product were recorded,and the effective dose(ED)was calculated.All images were evaluated according to the image quality scoring standard.The CT data were sent to the reconstruction company to produce accurate titanium implants,and neurosurgeons performed cranioplasty.Results The CTDIvol of routine dose group A and low dose group B,C and D were 24.32mGy,6.75mGy,4.05mGy and 2.61mGy,respectively.There was significant difference in DLP and ED among groups(P<0.001).The DIP and ED in low dose group D were 89.4%and 89.6%lower than those in routine dose group A(P<0.001).The images of each group could meet the requirements of imaging diagnosis,and there was no statistical difference(P>0.05).The reconstruction company successfully manufactured the titanium implant in line with the characteristics of each patient,and the cranioplasty was carried out smoothly.Postoperative CT showed that the titanium implant was well fixed,the skull shape was symmetrical,the aesthetic effect was remarkable,the clinical function recovered well,and patients satisfied.Conclusion Before cranioplasty,the patients with skull defect are scanned with low—dose skull 3D CT,made virtual 3D model and customizes titanium mesh implant,which not only flilly meet the clinical requirements,but also significantly reduces the radiation dose and the radiation hazard which has great practical value.