Iodine load reduction in dual-energy spectral CT portal venography with low energy images combined with adaptive statistical iterative reconstruction

Abstract

Objective: To study the application of using low energy images combined with adaptive statistical iterative reconstruction (ASiR) in dual-energy spectral CT portal venography (CTPV) to reduce iodine load. Methods: 41 patients for CTPV were prospectively and randomly divided into two groups. Group A ( n = 21) used conventional 120 kVp scanning protocol with contrast dose at 0.6 gI/kg while group B ( n = 20) used dual-energy spectral imaging with reduced contrast dose at 0.3 gI/kg. The 120 kVp images in Group A and 50 keV images in Group B were reconstructed with 40% ASiR. The contrast-to-noise ratio of portal vein was calculated. The image quality and the numbers of intrahepatic portal vein branches were evaluated by two experienced radiologists using a 5-point scoring system. Results: Group B reduced iodine load by 52% compared to Group A (17.21 ± 3.30 gI vs 35.80 ± 6.18 gI, p < 0.001). All images in both groups were acceptable for diagnosis. CT values and standard deviations in portal veins of Group B were higher than Group A (all p < 0.05); There were no statistical differences in contrast-to-noise ratio, image quality score and the number of observed portal vein branches between the two groups (all p > 0.05), and the two observers had excellent agreement in image quality assessment (all κ > 0.75). Conclusion: The use of 50 keV images in dual-energy spectral CTPV with ASiR reduces total iodine load by 52% while maintaining good image quality. Advances in knowledge: Spectral CT images combined with ASiR can be used in low contrast dose CTPV portal venography to maintain image quality and reduce contrast dose.

Clinical application of the contrast-enhancement boost technique in computed tomography angiography of the portal vein

“…Many efforts have been made to reduce the amount of contrast media as much as possible while maintaining portal vein image quality [ 17 , 20 ]. Han et al [ 21 ] used lower monoenergetic images combined with adaptive statistical iterative reconstruction (ASiR) in dual-energy spectral CT to reduce the iodine amount in CT portal venography (CTPV). They found that 50 keV images with ASiR reconstruction could reduce the total iodine amount by 52% while maintaining good image quality.…”

Dose reduction of iodinated contrast medium in CT: systematic review of the literature

“…In some of the studies reviewed [19][20][21][22][23]27,28,34,35,39,40 , a wide range of net iodine doses used in the different tests is described, in milligrams iodine per weight (mgI/kg), from 280 to 600 mgI/kg using SECT equipment, and when performing the same examination with DECT technology, said dose is reduced to a range of 140-510 mgI/kg.…”

Disminución de dosis de medio de contraste yodado en TC: revisión sistemática de la literatura

“…En algunos de los estudios revisados [19][20][21][22][23]27,28,34,35,39,40 se describe un amplio rango de dosis de yodo neto utilizadas en los diferentes exámenes, en miligramos yodo por peso (mgI/kg), desde 280 hasta 600 mgI/kg usando equipos de SECT, y al momento de realizar el mismo examen con tecnología DECT se disminuye dicha dosis hasta un rango de 140 a 510 mgI/kg.…”