Balancing act between quantitative and qualitative image quality between nonionic iodinated dimer and monomer at various vessel sizes during computed tomography: a phantom study.

Autor: Karout L; Diagnostic Radiology Department, American University of Beirut Medical Center, Beirut, American University of Beirut Medical Center, Beirut, Lebanon. P O Box: 11-0236 Riad El-Solh, Beirut, 1107 2020, Lebanon., El Asmar K, Naffaa L, Abi-Ghanem AS, El-Merhi F, Salman R, Saade C
Jazyk: angličtina
Zdroj: Biomedical physics & engineering express [Biomed Phys Eng Express] 2020 Mar 04; Vol. 6 (3), pp. 035001. Date of Electronic Publication: 2020 Mar 04.
DOI: 10.1088/2057-1976/ab78dc
Abstrakt: Purpose: Investigate the impact of nonionic dimer and monomer on iodine quantification in different vessel sizes when employing a vascular specific phantom and varying iodinated contrast media (ICM) concentrations during computed tomography (CT).
Materials and Methods: We created a vascular specific phantom (30 cm) to simulate human blood vessel diameters (25 cylinders of different diameters: 10 × 9mm, 10 × 12mm and 5 × 21mm). The phantom was filled with two ICM separately: Group: Iohexol(monomer)350 mg ml -1 and B: Iodixanol(Dimer)320 mg ml -1 . Cylinders of same size were filled with increasing ICM concentration(10%-100%) while large cylinders were filled in quartiles(25%-100%). Phantom was scanned with different tube potential (80-140kVp), current (50-400mAs), reconstruction method [filtered back projection (FBP), hybrid-based iterative reconstruction (HBIR) and model-based iterative reconstruction (MBIR)] for each ICM. Chi-square was employed to compare mean opacification, contrast/noise ratio (CNR) and noise. Qualitative analysis was assessed by Visual grading characteristic (VGC) and Cohens-kappa analyses.
Results: At 80 and140kVp significant difference in opacification between Group A (2054 ± 1040HU and 1696 ± 1027HU) and B (2169 ± 1105HU and 1568 ± 1034HU) was demonstrated (p < 0.001). However, at 100 and 120kVp no difference was noted (p > 0.05). When comparing image noise, it was higher in Group A compared to B (p < 0.05). CNR was higher in Group B (119.99 ± 126.10HU) than A (107.09 ± 102.56HU) (p < 0.0001). VGC: Group A outperformed B in image opacification in all vessel sizes and ICM concentrations except at medium vessels with concentration group 2(0.4-0.6 mg ml -1 ). Cohens'-kappa: agreement in opacification between each ICM group and iodine concentration 1(0-0.3 mg ml -1 ): κ = 0.253 and 0.014 respectively, concentration 2(0.4-0.6 mg ml -1 ):κ = -0.017 and -0.005 respectively and concentration 3(0.7-1 mg ml -1 ):κ = 0.031 and 0.115 respectively.
Conclusion: Nonionic dimer (Iodixanol) surpasses monomer (Iohexol) in quantitative image quality assessment by having lower image noise and higher CNR during CT.
Databáze: MEDLINE