摘要
探讨全模型迭代重建技术(iterative model reconstruction,IMR)在低管电压、低管电流、低造影剂总量与低流速条件下,在256层螺旋CT头颈部血管成像(CTA)中的可行性;并评估其对图像质量以及辐射剂量的影响。将50例行头颈部CTA检查的患者,随机分为对正常剂量和低剂量组,每组各25例。对照组选择120 kV、约220 mA·s、45 mL对比剂、流速4.5 mL/s。低剂量组选择80 kV、约155 mA·s、40 mL对比剂、流速4.0 mL/s,其余扫描条件保持一致。对照组使用滤波反投影法(FBP)对数据进行重建,低剂量组使用IMR算法对数据进行重建。对两组图像进行主观质量评价和客观统计分析包括强化CT值、信噪比(SNR)、对比噪声比(CNR)以及辐射剂量。结果 2名医师对动脉期图像质量评分一致性较高。低剂量组各段血管强化CT值、SNR、CNR均高于对照组,具有统计学意义(P<0.05)。低剂量组容积CT剂量指数(CTDI)、剂量长度乘积(DLP)和有效剂量(ED)明显低于正常剂量组。说明在头颈部CTA检查中采用低管电压、低管电流、低流速与低对比剂总量扫描模式结合IMR重建技术既可满足临床诊断的需求,又可以获得较好的图像质量和较低的辐射剂量。
To evaluate the feasibility of iterative model reconstruction technique for 256-slice spiral in CT angiography（ CTA） of cerebral and carotid,lower tube voltage,lower current,lower contrast medium and slow inject speed,and to assess the influence on image quality and radiation dose were used. Fifty patients who performed cerebral and carotid CTA inspection were randomly divided into normal dose group and low dose group,25 cases in each group. The voltage in normal dose group was 120 kV and the current was 220 m A·s using 45 mL contrast agent with a speed of 4. 5 mL / s. Those in low dose group were 80 kV and 155 mA·s using 40 mL contrast agent with a speed of 4. 0 mL / s. The subjective evaluation and objective statistical analysis including enhanced CT value,signal to noise ratio（ SNR）,contrast to noise ratio（ CNR） and radiation dose ware done on two groups artery images. The higher consistency of artery image quality score was acquired according to the assessment of two physicians. The vascular enhanced CT value,SNR and CNR in the low dose group were higher than the control group,with statistical significance（ P〈0. 05）. The volume CT dose index（ CTDI）,the product of dose length（ DLP） and the effective dose（ ED） in low dose group of significantly lower than the control group. The scan model using lower tube voltage,lower current,slow inject speed and lower contrast medium and iterative model reconstruction technique in cerebral and carotid CTA examination can result in high quality images which meet the diagnostic needs and obviously reduce radiation dosage.
出处
《科学技术与工程》
北大核心
2016年第35期34-39,共6页
Science Technology and Engineering
基金
广东省科技厅基于医学图像大数据的肿瘤精准诊断系统(2015B010131011)资助
关键词
头颈部CT血管成像
低剂量扫描
全模型迭代重建技术
图像质量
辐射剂量
CT angiography of cerebral and carotid
low dose scan model
iterative model reconstruction technique
image quality
radiation dose
