低剂量与常规剂量CT扫描在头颅检查中的对比研究

Comparative Study Between Low and Conventional Doses CT Scanning for Head Examination

目的对比分析低剂量与常规剂量头颅CT扫描的辐射剂量比以及低剂量扫描对图像质量的影响。方法对120例头颅患者作头颅CT扫描,分为220mA、100mA、80mA3种剂量扫描,评价3种剂量扫描的图像质量;分别记录3种剂量扫描CT剂量容积(CTDIvol)和剂量长度乘积DLP(mGy.cm)。结果与常规剂量220mA扫描比较,100mA扫描对头颅图像的观察诊断没有影响;80mA扫描时图像颗粒增粗,组织结构分辨率下降,影响观察诊断以220mA为标准,低剂量组80mA和100mA的CTDIvoI、DLP分别是常规剂量组的36.7%、36.7%和45.9%、45.9%。结论100mA低剂量CT扫描对头颅细微显示没有明显影响,不影响观察诊断,完全可应用于头颅扫描方法。

Objective To comparatively analyze the imeges＇ quality and radiation doses between the lowdose head CT and conventional-dose CT scanning. Methods 120 cases of patients with skull for head CT scanning were divided into 220mA, 100mA, 80mA dosage scanning groups respectively. All images were used for quality assessment, dose volume dose CT scan （CTDIvol） and dose-length product DLP （mGy ~ era）were recorded for radiation close evaluation. Results Compared with the conventional dose 220mA scan, dose 100mA scanning showed no impact on their observation of diagnostic images, dose 80mA scan affected the image＇s diagnosis because of particle image enlargement and organizational resolution descend. Compared to dose 220mA CTDIvoI, DLP of low-dose groups 80mA and lO0mA were respectively 36.7% , 36.7% and 45.9%, 45.9%. Conclusion 100mA low-dose CT scan of skull does not have obvious effects on image definition and clinical diagnosis, so it can be applied to the head scanning.