摘要
目的 探讨低管电压联合低对比剂剂量扫描技术在上肢血透通路CT血管成像中的可行性.方法 40例体重指数（BMI）≤25 kg/m2的维持性血透患者纳入研究,按检查时间顺序分2组,前20例为A组,80 kVp方案扫描,碘对比剂用量为0.42 gI/kg,后20例为B组,120 kVp方案扫描,对比剂用量为0.525 gI/kg.测量肱骨中段、肘关节以及尺桡骨中段处目标血管和周围肌肉的感兴趣区（ROI） CT值,计算图像的信噪比（SNR）和对比噪声比（CNR）,同时记录容积CT剂量指数（CTDIvol）与剂量长度乘积（DLP）.2位放射科医师对原始图像和重建图像进行主观质量评分.结果 A组血管区平均CT值（444.65±75.76）HU,显著高于B组的（278.20±42.95）HU（t =7.70,P ＜0.05）;A组肌肉区CT值（57.05±7.71）HU,显著高于B组的（51.55±5.81）HU（t=2.325,P ＜0.05）；2组间SNR和CNR未见统计学差异.A组的CTDIvol和DLP [（2.87±0.37）mGy,（196.44±28.83） mGy· cm]均显著小于B组（7.86 ±1.61）mGy,（521.14±101.73） mGy· cm（t=-12.380、-12.636,P＜0.05）.2位医师主观评分具有较好的一致性（K =0.76,P＜0.05）.结论 对于BMI≤25 kg/m2患者,80 kV联合低对比剂剂量成像方案可以获得良好上肢血透通路CTA成像.
Objective To evaluate the feasibility of low-kil0voltage combined with reduced contrast medium in hemodialysis access CT angiography. Methods Forty patients with maintained hemodialysis （BMI ≤25 kg/m2） were enrolled and divided into two groups. The protocol including 80 kV and CM dosage of 0. 42 gI/kg was used in group A （first 20 patients）. The protocol including 120 kV and CM dosage of 0. 525 gI/kg was used in group B （last 20 patients）. The patient was supine with the target arm aside the body and the other arm over the head. The contrast medium （350 mgI/ml） was administrated with the rate of 3.5 ml/s from the other arm vein. The cephalo-caudal scan was triggered with tracing technique. The CT values of artery and neighbouring muscle with ROIs in there levels （ middle humerus, elbow, and middle radius） were respectively measured, and SNR and CNR were calculated. The CTDIol and DLP were recorded. Results The mean CT value of the artery in group A（444.65 ± 75.76） HU, was higher than that in group B （ 278.20 ±42.95 ）HU（t=7.70, P 〈0.05）. The mean CT value of peripheral muscle （57.05 ±7.71 ）HU in group A was higher than that in group B （51.55 ± 5.81 ）HU （ t = 2. 325, P 〈 0. 05 ）. There were no statistical differences of SNR and CNR between the two groups. The CTDIvoI and DLP in group A [ （2.87 ± 0. 37） mGy, （ 196.44 ± 28.83） mGy· cm ] were significantly smaller than those in group B[（7.86±1.61） mGy , （ 521.14 ±101. 73 ） mGy＇cm （t= -12.380, -12.636,P〈 0. 05） ]. Two radiologists reached a good agreement on evaluating image quality （ K = 0. 76, P 〈 0. 05 ）. Conclusions The CTA protocol with 80 kV and reduced contrast medium could be used for evaluating the hemodialysis access in patients with BMI≤25 kg/m2.
出处
《中华放射医学与防护杂志》
CAS
CSCD
北大核心
2013年第2期201-204,共4页
Chinese Journal of Radiological Medicine and Protection
