A phantom study comparing low-dose CT physical image quality from five different CT scanners

Quantitative Imaging in Medicine and Surgery

article

Yaojun Jiang¹  Huilong Liu¹  Xi Yu¹  Sihui Chen¹  Duoshan Ma¹  Jianbo Gao¹  Yan Wu¹  Yali Li¹ 

[1] Department of Radiology , The First Affiliated Hospital of Zhengzhou University

关键词: Low-dose computed tomography (LDCT);    quantitative computed tomography (QCT);    phantom;    iterative reconstruction (IR);    deep learning;    image quality;   

DOI  :  10.21037/qims-21-245

学科分类：外科医学

来源: AME Publications

【 摘 要 】

Background: To systematically evaluate the physical image quality of low-dose computed tomography (LDCT) on CT scanners from 5 different manufacturers using a phantom model. Methods: CT images derived from a Catphan 500 phantom were acquired using manufacturer-specific iterative reconstruction (IR) algorithms and deep learning image reconstruction (DLIR) on CT scanners from 5 different manufacturers and compared using filtered back projection with 2 radiation doses of 0.25 and 0.75 mGy. Image high-contrast spatial resolution and image noise were objectively characterized by modulation transfer function (MTF) and noise power spectrum (NPS). Image high-contrast spatial resolution and image low-contrast detectability were compared directly by visual evaluation. CT number linearity and image uniformity were compared with intergroup differences using one-way analysis of variance (ANOVA). Results: 0.05). The resolution level at 10% MTF was 6.98 line-pairs-per-centimeter (lp/cm) on average, which was similar to the subjective evaluation results (mostly up to 7 lp/cm). DLIR at all 3 levels had the highest 50% MTF values among all reconstruction algorithms. For image low-contrast detectability, the minimum diameter of distinguishable contrast holes reached 4 mm at a 0.5% resolution. Increasing the radiation dose and IR strength reduced the image noise and NPS curve peak frequency while improving image low-contrast detectability. Conclusions: This study demonstrated that the image quality of CT scanners from 5 different manufacturers in LDCT is comparable and that the CT number linearity is unbiased and can contribute to accurate bone mineral density quantification.

【 授权许可】

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