迭代重组IMR技术和iDose4技术在腹部低剂量CT扫描乏血供肝转移瘤中的图像质量  

Iterative model reconstruction and hybrid iterative reconstruction techniques iDose4 in low-dose abdominal CT： comparison of image quality in evaluation of hypovascular metastases of liver

作　　者：王平[1] 高玉颖[1] 卢再鸣[1] 陆晓梅 费诚[1] 张朝亚[1] 

机构地区：[1]中国医科大学附属盛京医院放射科,沈阳110004 [2]飞利浦医疗中国影像研究学院

出　　处：《中华放射学杂志》2015年第4期283-287,共5页Chinese Journal of Radiology

摘　　要：目的探讨迭代重组IMR技术和iDose。技术在腹部低剂量CT扫描中评价乏血供肝转移瘤图像质量的价值。方法回顾性分析有原发恶性肿瘤手术病史和病理结果，且经≥3个月增强CT或增强MRI随访（每个月复查1次）证实的33例乏血供肝转移瘤患者。患者均行腹部CT平扫和动态增强扫描。将门静脉期低剂量扫描数据作为研究对象，根据管电流和重组算法不同将图像分为4组。A组：管电流175mAs，迭代重组IMR技术组（17例）；B组：管电流175mAs，迭代重组iDose。技术组（17例）；C组：管电流125mAs，迭代重组IMR技术组（16例）；D组：管电流125mAs，迭代重组iDose。技术组（16例）。多发病灶患者评价最大径最大的病灶。对各组图像进行客观评价咆括噪声、信噪比（SNR）、对比噪声比（CNR）]及主观评价（包括病灶边缘锐利度评分、病灶内部坏死与实性部分界面评分和诊断信心评分）。记录各种方案扫描的CT剂量指数。对A组和B组、C组和D组图像间客观指标的比较采用配对样本t检验，上述各组主观评价指标的比较采用Wilcoxon符号秩和检验。结果A组图像噪声、CNR和SNR分别为（7．7±1．8）HU、10．3±2．6、13．2±3．2，B组图像分别为（12．8±3．7）HU、5．6±1．4、8．1±2．2，差异均有统计学意义（t值分别为9．966、12．670、9．203，P均〈0．01）。C组图像噪声、CNR和SNR分别为（7．2±1．3）HU、7．4±2．0、13．9±2．9，D组图像分别为（9．9±1．8）HU、3．7±0．9、9．8±1．9，差异均有统计学意义（t值分别为9．209、12．320、9．628，P均〈0．01）。A组图像的病灶边缘锐利度评分、病灶内部坏死与实性部分界面评分和诊断信心评分分别为（4．95±0．24）、（4．76±0．36）、（4．94±0．24）分，B组图像上述评分分别为（4．29±0．59）、（3．68±0．30）、（4．44±0．56）分，C组分别为（3．Objective To assess the image quality of iterative model reconstruction algorithm （IMR） compared with hybrid iterative reconstruction algorithm （iDose4） for hypovascular hepatic metastases. Methods Medical history and pathological results of 33 cases with primary malignant tumor were retrospective analyzed. Follow-up with enhanced CT or enhanced MRI at more than 3 months confirmed hypovascular metastases in these patients. All patients underwent abdominal CT scanning and dynamic enhanced CT scanning. Portal vein phase of low dose scanning data were taken as the research object. According to the different tube currents and reconstruction algorithm, the images were divided into 4 groups. Group A included images with tube current of 175 mAs and IMR post-processing （17 cases）. Group B included images with tube current of 175 mAs and iDoseg post-processing （17 cases）. Group C included images with tube current of 125 mAs and IMR post-processing （16 cases）. Group D included images with tube current of 125 mAs and iDoseg post-processing （16 cases）. In the cases with multiple lesions, the largest lesion was selected to evaluate. For each image of the objective evaluation [including noise, the signal-to-noise ratio （SNR）, contrast to noise ratio （CNR）] and subjective evaluation （including lesion sharpness, necrosis interface and diagnostic confidence）. The CT dose index of each scanning was recorded. The objective evaluation, subjective evaluation indexes were compared by paired samples t test and Wilcoxon signed rank test. Results The tube current of Group A and Group B were （7.7± 1.8） and （12.8±3.7）HU, while CNR were 10.3±2.6 and 5.6 ± 1.4, SNR were 13.2 ± 3.2 and 8.1±2.2, and the differences were statistically significant （t values were 9.966, 12.670, 9.203; P〈0.01）. The tube current of Group C and Group D were （7.2±1.3） and （9.9±1.8）HU, while CNR were 7.4±2.0 and 3.7±0.9, SNR were 13.9±2.9 and 9.8±1.9, and the differences were statistically significa

关 键 词：肝肿瘤 体层摄影术 x线计算机 对比研究 

分 类 号：R735.7[医药卫生—肿瘤] R445.2[医药卫生—临床医学] R730.44