能谱CT个体化对比剂用量和低辐射剂量单能量CTU成像的临床应用价值  

Clinical value of individual contrast dosage and low radiation dose CTU with monochromatic imaging in spectral CT

作　　者：刘磊[1] 李泉林[1] 浦仁旺[1] 郑邵微[1] 葛莹[1] 田士峰[1] 

机构地区：[1]大连医科大学附属第一医院,辽宁大连116011

出　　处：《中国临床医学影像杂志》2015年第7期498-501,共4页Journal of China Clinic Medical Imaging

摘　　要：目的:探讨个体化对比剂用量、低辐射剂量单能量扫描CTU成像临床应用的可行性及优势。方法:将95例行CTU检查的分成2组,A组为对照组58例,B组为试验组37例,所有病例均在GE Discovery HD CT上完成。A组采用常规扫描方案:120 k Vp,3D自动m A和噪声指数15 HU、扫描时间0.8 s、层厚5 mm、螺距1.375∶1、图像处理50%ASIR、重建方式Stnd、重建1.25 mm层厚图像,对比剂用量均为100 m L、注射速度为4.0 m L/s。B组采用GSI扫描方案:80/140 k Vp瞬切、275 m A、余扫描参数同A组,重建85 ke V、1.25 mm层厚单能量图像,对比剂用量按300 mg I/kg,注射速度为对比剂容积(m L)/30 s。A、B两组对比剂均为碘海醇(含碘量350 mg/m L)。测量A、B两组膀胱内对比剂及臀大肌组织的CT值及噪声(SD)值,计算CNR,记录病人的体质量、容积剂量指数CTDIvol和DLP。A、B两组组间的CT值、SD值、CNR、CTDIvol、DLP、对比剂用量和注射速率比较采用独立样本t检验。由2名具有5年以上工作经验的影像诊断医生对VR、MIP图像质量进行5分制主观评价,评价结果的一致性检验采用Kappa分析,以Mann-Whitney U检验比较两组评分差异。结果:A、B组病人体质量为(66.20±12.98)kg、(69.19±10.16)kg,无统计学差异(P>0.05);A、B组膀胱内对比剂的CT值分别为(437.37±227.50)HU、(569.73±265.74)HU,有统计学差异;SD值为43.99±36.66、47.04±33.82,无统计学差异(P>0.05);图像的CNR为29.23±19.03、40.14±22.35,有统计学差异(P<0.05);CTDIvol为(10.12±4.97)m Gy、(7.64±0.00)m Gy,DLP为(452.52±234.20)m Gy、(357.32±36.88)m Gy,均有统计学差异(P均<0.05);对比剂用量为(100.00±0.00)m L、(59.17±8.74)m L、注射速度为(4.00±0.00)m L/s、(2.01±0.37)m L/s,有统计学差异(P均<0.05);图像质量评价为4.65±0.57、4.68±0.56,无统计学差异(P>0.05);2名医师对图像质量评分的Kappa检验分别为0.880、0.871,一致性非常好。结论:个体化对比剂用量、低辐射剂量单能量扫Objective： To investigate the feasibility and advantages of individual contrast dosage and low radiation dose scan using monochromatic CTU imaging. Methods： Ninety-five patients underwent CTU scanning on GE Discovery HD CT were divided into 2 groups, including 57 cases in control group（group A） and 38 cases in study group（group B）. Group A was given conventional scanning program： 120 kVp, 3D auto mA and noise index 15 HU, scan time 0.8 s, thickness 5 mm, pitch 1.375：1, the image processing 50% ASIR, reconstruction Stnd, thickness 1.25 mm, the amount of contrast agent are 100 mL, injection speed of 4.0 mL/s. Group B was given GSI scanning mode： 80/140 kVp fast switching, 275 mA. Other parameters were same with group A, reconstruction 85 keV, 1.25 mm thickness of a monochromatic image, the amount of contrast agent was 300 mgI/kg, speed of contrast agent injection was volume （mL）/30 s. Iohexol were used in two groups as contrast agent （iodine content of 350 mg/mL）. CT values and SD value （noise） of gluteus maximums and contrast agent in bladder were measured in both two groups for calculation of CNR. Patients＇ weight, volume dose index CTDIvol and DLP were recorded. CT values, SD values, CNR, CTDIvol, DLP, the amount of contrast agent and injection rates were compared between two groups using independent sample t test. The quality of VR and MIP images were evaluated by two radiology physicians with five years of experience using five-point scale, and the results of the consistency test using Kappa analysis, subjective rating were compared by Mann-Whitney U. Results： There were no significant difference of patients weight and SD value between two groups. The mean CT value of bladder contrast agent in group B （569.73±265.74） was statistically higher than group A （437.37±227.50）（P〈0.05）. The value of CNR in group B （40.14±22.35） was statistically higher than group A （29.23±19.03）（P〈0.05）. The value of CTDIvol, DLP, amount of contrast agent and injection

关 键 词：辐射剂量 体层摄影术 螺旋计算机 尿路造影术 

分 类 号：R814.42[医药卫生—影像医学与核医学] R814.43[医药卫生—放射医学]