胸部双能减影的运动伪影分析与对策探讨

Analysis of motion artifact in chest dual energy subtraction and discussion of countermeasure

目的分析胸部双能减影的运动伪影(MA)。方法对连续抽取的211例胸部双能减影,评价运动伪影的影像特征及图像满意度。运动伪影可分为:没有、轻、中、重4级,整体图像满意度分为:优、良、中、差4级。结果运动伪影表现为在运动方向上被观察结构边界处出现的黑色或白色条纹影。双侧中、下肺野内带、双侧下肺野中带以及左中肺野中带、心缘旁、横膈、骨性胸廓是最容易出现运动伪影的部位。左下心缘是重度伪影最常见的部位。心脏搏动在所有病例中参与了运动伪影形成,呼吸运动和胸部移动分别在91.0%和6.2%的病例中参与了运动伪影形成。图像满意度为中等及以上者共占所有病例的80.1%。结论运动伪影是影响胸部双能减影图像质量的重要因素,呼吸运动和心脏搏动是运动伪影的主要来源,从抑制运动伪影入手,可进一步提高胸部双能减影图像质量。

Objective The objective of this study was to analyze the motion artifacts（MA） of dual energy subtraction（DES）. Methods Two hundred and eleven consecutive cases of DES were analyzed on the manifestation of MA and image satisfaction. Results MA were manifested as black or white stripes on the border of structure in direction of movement. The positions in which motion artifacts were most easy to be found included inner sections of bilateral middle and lower lung fields, central sections of bilateral lower lung fields, central section of left middle lung field, the borders of heart, the borders of diaphragm, the borders of osseous thorax. Severe MA were most likely to be found in inner sections of bilateral middle and lower lung fields and left lower border of heart. MA caused by heart beating was observed in all cases. Respiration movement and chest shift separately bring MA in 91.0% and 6.2% cases. Image satisfaction of middle lever and better accounted for 80. 1% cases. Conclusion MA was an important factor affecting image quality. The dominating origins of MA were heart beating and respiration movement. Reducing MA benefits improving image quality.