Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA.
Radiology. 2010 Dec;257(3):732-42. doi: 10.1148/radiol.10092016. Epub 2010 Oct 19.
To determine the computed tomographic (CT) detector configuration, patient size, and image noise limitations that will result in acceptable image quality of 80-kV images obtained at abdominal dual-energy CT.
The Institutional Review Board approved this HIPAA-compliant retrospective study from archival material from patients consenting to the use of medical records for research purposes. A retrospective review of contrast material-enhanced abdominal dual-energy CT scans in 116 consecutive patients was performed. Three gastrointestinal radiologists noted detector configuration and graded image quality and artifacts at specified levels-midliver, midpancreas, midkidneys, and terminal ileum-by using two five-point scales. In addition, an organ-specific enhancement-to-noise ratio and background noise were measured in each patient. Patient size was measured by using the longest linear dimension at the level of interest, weight, lean body weight, body mass index, and body surface area. Detector configuration, patient sizes, and image noise levels that resulted in unacceptable image quality and artifact rankings (score of 4 or higher) were determined by using multivariate logistic regression.
A 14 × 1.2-mm detector configuration resulted in fewer images with unacceptable quality than did the 64 × 0.6-mm configuration at all anatomic levels (P = .004, .01, and .02 for liver, pancreas, and kidneys, respectively). Image acceptability for the kidneys and ileum was significantly greater than that for the liver for all readers and detector configurations (P < .001). For the 14 × 1.2-mm detector configuration, patient longest linear dimensions yielding acceptable image quality across readers ranged from 34.9 to 35.8 cm at the four anatomic levels.
An 80-kV abdominal CT can be performed with appropriate diagnostic quality in a substantial percentage of the population, but it is not recommended beyond the described patient size for each anatomic level. The 14 × 1.2-mm detector configuration should be preferred.
确定能在腹部双能 CT 中获得可接受的 80kV 图像质量的 CT 探测器配置、患者体型和图像噪声限制。
本 HIPAA 合规的回顾性研究使用了同意将病历用于研究目的的患者的存档材料，经机构审查委员会批准。对 116 例连续患者的增强腹部双能 CT 扫描进行了回顾性分析。三位胃肠道放射科医生使用两个五分制量表，在特定水平（肝中部、胰腺中部、肾中部和回肠末端）记录探测器配置和图像质量及伪影评分。此外，还在每位患者中测量了特定器官的增强与噪声比和背景噪声。患者体型通过在感兴趣层面测量最长线性尺寸、体重、瘦体重、体重指数和体表面积来确定。使用多元逻辑回归确定导致图像质量和伪影评分（4 或更高）不可接受的探测器配置、患者体型和图像噪声水平。
在所有解剖水平上，14×1.2mm 探测器配置的不可接受图像质量的比例均低于 64×0.6mm 探测器配置（肝、胰腺和肾脏分别为 P=0.004、0.01 和 0.02）。对于所有读者和探测器配置，肾和回肠的图像可接受性均显著大于肝（P<0.001）。对于 14×1.2mm 探测器配置，读者认为图像质量可接受的患者最长线性尺寸在四个解剖水平上的范围为 34.9 至 35.8cm。
在相当大比例的人群中，80kV 腹部 CT 可实现适当的诊断质量，但不建议超出每个解剖水平的描述性患者体型。应首选 14×1.2mm 探测器配置。
