低噪声可显著减少腹部 CT 的螺旋伪影。

Low pitch significantly reduces helical artifacts in abdominal CT.

机构信息

Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, 1400 Pressler Street, Unit 1473, Houston, TX 77030-4009, United States.

Department of Biostatistics, The University of Texas MD Anderson Cancer Center, 1400 Pressler Street, Unit 1473, Houston, TX 77030-4009, United States.

出版信息

Eur J Radiol. 2023 Sep;166:110977. doi: 10.1016/j.ejrad.2023.110977. Epub 2023 Jul 13.

DOI:10.1016/j.ejrad.2023.110977

PMID:37481832

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC10529376/

Abstract

PURPOSE

High helical pitch scanning minimizes scan times in CT imaging, and thus also minimizes motion artifact and mis-synchronization with contrast bolus. However, high pitch produces helical artifacts that may adversely affect diagnostic image quality. This study aims to determine the severity and incidence of helical artifacts in abdominal CT imaging and their relation to the helical pitch scan parameter.

METHODS

To obtain a dataset with varying pitch values, we used CT exam data both internal and external to our center. A cohort of 59 consecutive adult patients receiving an abdomen CT examination at our center with an accompanying prior examination from an external center was selected for retrospective review. Two expert observers performed a blinded rating of helical artifact in each examination using a five-point Likert scale. The incidence of artifacts with respect to the helical pitch was assessed. A generalized linear mixed-effects regression (GLMER) model, with study arm (Internal or External to our center) and helical pitch as the fixed-effect predictor variables, was fit to the artifact ratings, and significance of the predictor variables was tested.

RESULTS

For a pitch of <0.75, the proportion of exams with mild or worse helical artifacts (Likert scores of 1-3) was <1%. The proportion increased to 16% for exams with pitch between 0.75 and 1.2, and further increased to 78% for exams with a pitch greater than 1.2. Pitch was significantly associated with helical artifact in the GLMER model (p = 2.8 × 10), while study arm was not a significant factor (p = 0.76).

CONCLUSION

The incidence and severity of helical artifact increased with helical pitch. This difference persisted even after accounting for the potential confounding factor of the center where the study was performed.

摘要

目的

高螺旋桨扫描能最大限度地减少 CT 成像的扫描时间，从而最大限度地减少运动伪影和与对比剂团块的失步。然而，高螺距会产生螺旋伪影，可能会对诊断图像质量产生不利影响。本研究旨在确定腹部 CT 成像中螺旋伪影的严重程度和发生率及其与螺旋桨扫描参数的关系。

方法

为了获得具有不同螺距值的数据集，我们使用了内部和外部的 CT 检查数据。我们选择了 59 例连续的成年患者，他们在我们的中心接受了腹部 CT 检查，同时还回顾了来自外部中心的前一次检查。两名专家观察者使用 5 分李克特量表对每个检查中的螺旋伪影进行了盲法评分。评估了相对于螺旋桨的伪影发生率。采用广义线性混合效应回归（GLMER）模型，以研究臂（我们中心内部或外部）和螺旋桨为固定效应预测变量，对伪影评分进行拟合，并检验预测变量的显著性。

结果

对于螺距<0.75 的检查，轻度或更严重的螺旋伪影（Likert 评分 1-3）的检查比例<1%。螺距在 0.75-1.2 之间的检查比例增加到 16%，而螺距大于 1.2 的检查比例进一步增加到 78%。GLMER 模型中螺距与螺旋伪影显著相关（p=2.8×10），而研究臂不是一个显著因素（p=0.76）。