能谱CT智能匹配技术在不同体质量指数患者腹部CT扫描中的应用

发布时间：2018-03-23 14:56

  本文选题：能谱　切入点：智能匹配　出处：《临床放射学杂志》2017年07期

【摘要】：目的评估能谱CT智能匹配技术(GSI assist)在不同体质量指数(BMI)患者腹部CT扫描中的图像噪声和辐射剂量,并与120 kVp常规扫描进行对比研究。方法搜集行能谱CT全腹部增强扫描患者76例,扫描前记录每例患者的BMI。平扫采用120 kVp、自动管电流调制扫描,采用滤波反投影(FBP)、30%和50%自适应统计迭代重建(ASiR)3组图像;增强采用GSI成像模式,打开GSI assist并设置与平扫相同噪声指数,自动选择最佳能谱参数扫描,重建静脉期65 keV单能量图像。根据患者BMI将所有患者分为4组,A组:BMI18.5 kg/m~2;B组:BMI18.5~23.9 kg/m~2;C组:BMI 24~28.9 kg/m~2;D组:BMI≥29 kg/m~2。记录各组患者常规120 kVp和GSI assist两种扫描模式的容积CT剂量指数(CTDIvol),并测量4组图像腹壁皮下脂肪和膀胱的图像噪声。采用配对t检验比较各组患者GSI assist模式扫描和常规120 kVp扫描的图像噪声和辐射剂量。结果 GSI assist模式扫描和常规120 kVp扫描的CTDIvol在各组分别为:A组:(8.2±2.3)mGy和(6.5±2.2)mGy;B组:(11.3±3.2)mGy和(10.8±3.4)mGy;C组:(17.9±3.7)mGy和(18.3±4.3)mGy;D组:(18.9±4.7)mGy和(20.4±5.6)mGy。GSI assist模式扫描CTDIvol在A组低于120 kVp常规扫描(P0.05),在B组和C组与120 kVp常规扫描差异无统计学意义(P0.05),在D组高于120 kVp常规扫描(P0.05)。4组患者65 keV单能量图像皮下脂肪和膀胱噪声均低于120 kVp联合FBP图像(P0.05),高于120 kVp联合50%ASiR图像(P0.05),与120 kVp联合30%ASiR图像差异无统计学意义(P0.05)。结论能谱CT智能匹配技术可以降低低BMI患者的辐射剂量;其65 keV单能量图像噪声与常规120 kVp扫描联合30%ASiR图像相当,低于常规扫描FBP重建图像。
[Abstract]:Objective to evaluate the image noise and radiation dose of energy dispersive CT intelligent matching technique (GSI assist) in abdominal CT scans of patients with different body mass index (BMIs). Methods 76 patients with total abdominal enhanced scanning with energy dispersive computed tomography (EDS) were collected and compared with the conventional scan of 120 kVp. The BMIs of each patient were recorded before scanning. The normal scan was performed with 120kVp, and the automatic tube current modulation scan was used. The 30% and 50% adaptive statistical iterations of filtering backprojection are used to reconstruct the three groups of images, the GSI imaging mode is used to enhance the image, the GSI assist is opened and the same noise index is set up with the same noise index as the plain scan, and the best energy spectrum parameter scan is automatically selected. All patients were divided into 4 groups according to BMI. Group A was divided into 4 groups: group A: BMI18.5 / kgmmm2OB group: BMI18.5kg / kg / m2KM group (group C): BMI18.5kg / kg / m-1 group (group C): BMI249kg / mmm2D group: BMI 鈮，

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