Institute for Diagnostic and Interventional Radiology, University Hospital Zurich, Raemistrasse 100, 8091, Zurich, Switzerland,
Eur Radiol. 2014 Mar;24(3):657-67. doi: 10.1007/s00330-013-3049-x. Epub 2013 Oct 24.
To determine the value of combined automated attenuation-based tube-potential selection and iterative reconstructions (IRs) for optimising computed tomography (CT) imaging of hypodense liver lesions.
A liver phantom containing hypodense lesions was imaged by CT with and without automated attenuation-based tube-potential selection (80, 100 and 120 kVp). Acquisitions were reconstructed with filtered back projection (FBP) and sinogram-affirmed IR. Image noise and contrast-to-noise ratio (CNR) were measured. Two readers marked lesion localisation and rated confidence, sharpness, noise and image quality on a five-point scale (1 = worst, 5 = best).
Image noise was lower (31-52%) and CNR higher (43-102%) on IR than on FBP images at all tube voltages. On 100-kVp and 80-kVp IR images, confidence and sharpness were higher than on 120-kVp FBP images. Scores for image quality score and noise as well as sensitivity for 100-kVp IR were similar or higher than for 120-kVp FBP and lower for 80-kVp IR. Radiation dose was reduced by 26% at 100 kVp and 56% at 80 kVp.
Compared with 120-kVp FBP images, the combination of automated attenuation-based tube-potential selection at 100 kVp and IR provides higher image quality and improved sensitivity for detecting hypodense liver lesions in vitro at a dose reduced by 26%.
• Combining automated tube voltage selection/iterative CT reconstruction improves image quality. • Attenuation values remain stable on IR compared with FBP images. • Lesion detection was highest on 100-kVp IR images.
确定基于自动衰减的管电压选择和迭代重建（IR）联合应用于优化低密度肝脏病变 CT 成像的价值。
使用 CT 对含有低密度病变的肝脏模型进行扫描，分别在有和无基于自动衰减的管电压选择（80、100 和 120kVp）的情况下进行。采用滤波反投影（FBP）和正弦图确认的迭代重建（IR）进行采集重建。测量图像噪声和对比噪声比（CNR）。两位读者对病变定位进行标记，并对五个等级（1=最差，5=最好）的置信度、锐利度、噪声和图像质量进行评分。
在所有管电压下，IR 图像的噪声均低于（31%-52%），CNR 高于（43%-102%）FBP 图像。在 100kVp 和 80kVp IR 图像上，置信度和锐利度均高于 120kVp FBP 图像。100kVp IR 图像的图像质量评分、噪声评分和检测灵敏度与 120kVp FBP 相似或更高，而 80kVp IR 图像的噪声评分则更低。100kVp 时辐射剂量减少了 26%，80kVp 时减少了 56%。
与 120kVp FBP 图像相比，在 100kVp 时结合基于自动衰减的管电压选择和 IR 可提供更高的图像质量和改善的检测敏感性，同时体外剂量减少 26%。
• 联合使用自动管电压选择/迭代 CT 重建可提高图像质量。
• 与 FBP 图像相比，IR 上的衰减值保持稳定。
• 100kVp IR 图像上的病变检测率最高。
