100kV低管电压扫描与iDose^4重建并用在头颈联合CTA检查中的应用价值

Application value of 256-slice spiral CT scan using 100kV tube voltage and iDose4 reconstruction in cervical and cranial computed tomographic angiography

目的探讨100kV低管电压扫描与iDose^4重建并用在头颈联合CT血管造影(CTA)检查的辐射剂量及其对图像质量的影响。方法 102例头颈联合CTA均采用100kV低管电压扫描及iDose^4重建检查。CTA图像按体质指数(BMI)分为A(BMI≤18.5 kg/m^2,22例)、B(18.5 kg/m^2<BMI<25.0 kg/m^2,34例)、C(25.0 kg/m^2≤BMI<28.0 kg/m^2,35例)、D(BMI≥28.0 kg/m^2,11例)4组,对各组进行1~5级质量评分。平均评分采用方差分析及SNK-q检验。结果剂量长度乘积(380.53±10.40)m Gy·cm,有效剂量1.18 m Sv。A^D组平均评分分别为(4.55±0.60)分、(3.88±0.77)分、(3.31±0.53)分、(2.73±0.47)分,差异有统计学意义(F=27.4433,P<0.000 1);组间比较差异均有统计学意义(P<0.01),随BMI增加评分降低,整体CTA图像仍可诊断。102例头颈联合CTA检查共发现血管狭窄性病变371处,其中颈部251处(67.7%)、颅内120处(32.3%);狭窄为轻度244处、中度67处、重度33处、闭塞27处。颅内动脉瘤10例13枚;左椎动脉及左颈总动脉开口变异5例。结论100kV低管电压扫描与iDose^4重建并用头颈联合CTA检查在大幅度降低辐射剂量的同时较好地显示了病变,应常规应用。

Objective To research radiation dose and CT image quality by using 100 kV tube voltage CT Scan and iDose^4 reconstruction in cervical and cranial computed tomographic angiography （CTA）. Methods Total 102 patients were scanned using 100 kV tube voltage and iDose^4 reconstruction in cervical and cranial. CTA images were grouped into A, B , C and D according to BMI,where Group A included 22 cases （BMI ≤ 18.5 kg/m^2）, Group B 34 cases（ 18.5 kg/m^2 〈 BMI 〈 25 kg/m^2 ）, Group C 35 cases （ 25 kg/m^2 ≤ BMI 〈 28 kg/m^2 ）, Group D 11 cases （ BMI ≥ 28 kg/m^2 ）, and rated 1 to 5 scores to all cases by CTA image quality. These average score of 4 groups were compared using analysis of variance and SNK-q test. Results The dose-length product（DLP） was （380.53 ± 10.40）mGy - cm,and the effective dose was 1.18 mSv. CTA image quality scores in each group were 4.55 ± 0.60 in group A,3.88 ± 0.77 in group B,3.31 ± 0.53 in group C, and 2.73 ± 0. 47 in group D, the difference was statistically significant （ F = 27. 4433, P 〈 0. 0001 ） ; The image quality between groups compared by using SNK-q test was significant（P 〈 0.01 ）. The score decreased with the increase of BMI, but CTA image quality of all cases met clinical requirement. Among the 102 patients examined by CTA, there were 371 segments for the head and neck artery stenosis,which distributed 251 in neck（67.7% ） and 120 in head（32.3% ）. Among these,244 were the mild stenosis ,67 were moderate stenosis ,33 were severe, and about 27 segments were occlu- sion. Besides,there were 10 cases were with artery aneurysms （13 gold） ,and 5 cases with the variation in opening of left vertebral artery and common carotid artery. Conclusion The cervical and cranial computed tomographic angiography u- sing 100 kV tube voltage CT scan and iDose^4 reconstruction can get good lesion display ,while significantly reduce the radiation dose.