基于模型的迭代重建在HRCT评价早期周围型肺癌中的应用价值  

The value of HRCT reconstructed with model-based iterative reconstruction algorithm for evaluating early peripheral lung cancers

作　　者：贾永军 于勇 段海峰 杨创勃 贺太平 町田治彦 沈云[2] 

机构地区：[1]陕西中医药大学附属医院影像科,陕西咸阳712083 [2]日本东京女子医科大学东医疗中心,日本东京163800

出　　处：《实用放射学杂志》2018年第2期278-282,共5页Journal of Practical Radiology

摘　　要：目的 比较滤波反投影重建（FBP）、自适应统计迭代重建（ASIR）、基于模型的迭代重建（MBIR）3种重建算法对胸部高分辨率CT（HRCT）图像质量的影响，探讨MBIR在HRCT评价周围型肺癌中的应用价值。方法 使用能谱CT扫描静止状态下体模以客观比较0.625 mm层厚FBP、ASIR（40%ASIR和FBP混合）和MBIR重建图像的噪声、空间分辨率和密度分辨率。回顾性收集行常规剂量胸部HRCT 扫描发现肺结节并术后确诊周围型肺癌患者30例，分别行FBP、ASIR和MBIR重建，比较3组图像的皮下脂肪和背部肌肉CT值与标准差值（SD），SD代表噪声。由2名放射科医师分别盲法对胸部图像质量及肺癌结节主观评分。结果 3组图像CT值差异无统计学意义（P〉0.05）；与FBP（31.58±5.21、24.39±5.08）和ASIR（24.55±4.14、19.20±4.11）比较，MBIR重建图像在肌肉（12.63±1.70）和脂肪（12.77±2.53）内SD减低明显（P〈0.05）。3组图像主观评分差异有统计学意义（P〈0.05），FBP主观噪声评分最低，MBIR主观噪声评分最高；MBIR在小血管和支气管的清晰度、肺癌结节内外部特征评分最高。结论 MBIR有利于降低肺部HRCT图像SD和提高细小结构清晰度、肺癌结节内外部细节分析，相比FBP和ASIR，MBIR在HRCT评价肺癌结节临床应用中优势明显。Objective To demonstrate the feasibility of high-resolution computed tomography （HRCT） reconstructed with a modeLhased iterative reconstruction （MBIR） for evaluating early peripheral lung cancer （≤3 cm）, by comparing image quality obtained from MBIR, filtered back projection reconstruction （ FBP）and state of the art adaptive statistical iterative reconstruction （ASIR） algorithm respectively.Methods A total of 30 patients confirmed with lung cancer by postoperative pathology were enrolled in the study. A chest phantom was also used to evaluate image noise, spatial resolution and density resolution. Both patients and chest phantom were received HRCT,and the images were reconstructed using FBP,ASIR （40% ASIR and FBP mix） and MBIR. The objective CT value, standard deviation（SD） and signal noise ratio （SNR） were measured.Two radiologists used a semi-quantitative to rate subjective image quality of lung nodules.Results There was no significant difference in CT value between the three reconstruction algorithms （ P〉0.05）. But significant improvements in objective image noise were observed in MBIR compared with FBP and ASIR （P〈0.05）： including the SD value in back muscle [-（12.63±1.70） with MBIR vs （31.58±5.21） with FBP and （24.55±4.14） with ASIR], and in subcutaneous fat [ （ 12.77± 2.53 ） vs { 24.39± 5.08） and （ 19.20± 4.11 ） ].Subjective image noise of the three group were also significantly difference： FBP with lowest subjective noise score;and MBIR with highest subjective noise score.The sharpness of small vessels and bronchi and diagnostic acceptability with MBIR were significantly better than with FBP and ASIR （P〈 0.05）.Conclusion Lung HRCT reconstructed with MBIR provides diagnostically more acceptable images for the detailed analyses of peripheral lung cancer compared with FBP and ASIR.

关 键 词：基于模型的迭代重建 自适应统计迭代重建 滤波反投影 计算机体层成像 

分 类 号：R814.42[医药卫生—影像医学与核医学] R734.2[医药卫生—放射医学]