The Application of a New Model-Based Iterative Reconstruction in Low-Dose Upper Abdominal CT

Yongjun Jia; Bingying Zhai; Taiping He; Yong Yu; Nan Yu; Haifeng Duan; Chuangbo Yang; Xirong Zhang

doi:10.1016/j.acra.2018.11.020

The Application of a New Model-Based Iterative Reconstruction in Low-Dose Upper Abdominal CT

Acad Radiol. 2019 Oct;26(10):e275-e283. doi: 10.1016/j.acra.2018.11.020. Epub 2019 Jan 17.

Authors

Yongjun Jia¹, Bingying Zhai², Taiping He³, Yong Yu³, Nan Yu³, Haifeng Duan³, Chuangbo Yang³, Xirong Zhang³

Affiliations

¹ Department of Radiology, Affiliated Hospital of Shaanxi Chinese Medicine University, No. 2, Weiyang West Road, Xianyang City 712000, Shaanxi Province, China. Electronic address: 404754002@qq.com.
² Department of Critical Care Medicine, Xianyang Hospital of Yan'an University, Xianyang, China.
³ Department of Radiology, Affiliated Hospital of Shaanxi Chinese Medicine University, No. 2, Weiyang West Road, Xianyang City 712000, Shaanxi Province, China.

PMID: 30660470
DOI: 10.1016/j.acra.2018.11.020

Abstract

Rationale and objectives: To compare upper abdominal computed tomography (CT) image quality of new model-based iterative reconstruction (MBIR) with low-contrast resolution preference (MBIR_NR40), conventional MBIR (MBIR_c), and adaptive statistical iterative reconstruction (ASIR) at low dose with ASIR at routine-dose.

Materials and methods: Study included phantom and 60 patients who had initial and follow-up CT scans. For patients, the delay phase was acquired at routine-dose (noise index = 10 HU) for the initial scan and low dose (noise index = 20 HU) for the follow-up. The low-dose CT was reconstructed with 40% and 60% ASIR, MBIR_c, and MBIR_NR40, while routine-dose CT was reconstructed with 40% ASIR. CT value and noise measurements of the subcutaneous fat, back muscle, liver, and spleen parenchyma were compared using one-way ANOVA. Two radiologists used semiquantitative 7-scale (-3 to +3) to rate image quality and artifacts.

Results: The phantom study revealed superior low-contrast resolution with MBIR_NR40. For patient scans, the CT dose index for the low-dose CT was 3.00 ± 1.32 mGy, 75% lower than the 11.90 ± 4.75 mGy for the routine-dose CT. Image noise for the low-dose MBIR_NR40 images was significantly lower than the low-dose MBIR_c and ASIR images, and routine-dose ASIR images (p < 0.05). Subjective ratings showed higher image quality for low-dose MBIR_NR40, with lower noise, better low-contrast resolution for abdominal structures, and finer lesion contours than those of low-dose MBIR_c and ASIR images, and routine-dose ASIR images (p < 0.05).

Conclusion: MBIR_NR40 with low-contrast resolution preference provides significantly lower noise and better image quality than MBIR_c and ASIR in low-dose abdominal CT; significantly better objective and subjective image quality than the routine-dose ASIR with 75% dose reduction.

Keywords: Abdominal CT; Adaptive statistical iterative reconstruction; Model-based iterative reconstruction; Radiation dose; X-ray computed tomography.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Aged
Aged, 80 and over
Algorithms
Artifacts
Digestive System Diseases / diagnostic imaging*
Female
Humans
Male
Middle Aged
Phantoms, Imaging
Radiation Dosage*
Radiographic Image Interpretation, Computer-Assisted / methods*
Radiography, Abdominal / methods*
Reproducibility of Results
Tomography, X-Ray Computed / methods*