Possible Contrast Media Reduction with Low keV Monoenergetic Images in the Detection of Focal Liver Lesions: A Dual-Energy CT Animal Study.

Yong Eun Chung,Hye-Jeong Lee,Joon Seok Lim,Hye Sun Lee,Song-Ee Baek,Je Sung You,Myeong-Jin Kim,Yingmei Feng

doi:10.1371/journal.pone.0133170

Yong Eun Chung, Hye-Jeong Lee + Show 6 more

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https://doi.org/10.1371/journal.pone.0133170

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Journal: PloS one	Publication Date: Jul 23, 2015
Citations: 21	License type: CC BY 4.0

Affiliation: Yonsei University, Severance Hospital

Abstract

ObjectiveTo investigate the feasibility of dual-energy CT for contrast media (CM) reduction in the diagnosis of hypervascular and hypovascular focal liver lesions (FLL).Subjects and MethodsThe Institutional Animal Care and Use Committee approved this study. VX2 tumors were implanted in two different segments of the liver in 13 rabbits. After 2 weeks, two phase contrast enhanced CT scans including the arterial phase (AP) and portal-venous phase (PVP) were performed three times with 24-hour intervals with three different concentrations of iodine, 300 (I300), 150 (I150) and 75 mg I/mL (I75). The mean HU and standard deviation (SD) were measured in the liver, the hypervascular portion of the VX2 tumor which represented hypervascular tumors, and the central necrotic area of the VX2 tumor which represented hypovascular tumors in 140kVp images with I300 as a reference standard and in monoenergetic images (between 40keV and 140keV) with I150 and I75. The contrast-to-noise ratio (CNR) for FLLs and the ratio of the CNRs (CNRratio) between monoenergetic image sets with I150 and I75, and the reference standard were calculated.ResultsFor hypervascular lesions, the CNRratio was not statistically different from 1.0 between 40keV and 70keV images with I150, whereas the CNRratio was significantly lower than 1.0 in all keV images with I75. For hypovascular lesions, the CNRratio was similar to or higher than 1.0 between 40keV and 80keV with I150 and between 40keV and 70keV with I75.ConclusionsWith dual-energy CT, the total amount of CM might be halved in the diagnosis of hypervascular FLLs and reduced to one-fourth in the diagnosis of hypovascular FLLs, while still preserving CNRs.

Highlights

Similar to statistics compiled during the early eighties, contrast-induced nephropathy (CIN) is still found to be the third leading cause of hospital-acquired acute renal insufficiency and it accounts for 11–12% of all hospital-acquired acute renal insufficiency cases [1,2,3]
With dual-energy CT, the total amount of contrast media (CM) might be halved in the diagnosis of hypervascular focal liver lesion (FLL) and reduced to one-fourth in the diagnosis of hypovascular FLLs, while still preserving contrast-to-noise ratio (CNR)
The standard deviation (SD) was lowest in 70 keV and rapidly increased in keV values lower than 70 keV in both the arterial phase (AP) and portal-venous phase (PVP) and with both I75 and I150 (Fig 3)

Summary

Introduction

Similar to statistics compiled during the early eighties, contrast-induced nephropathy (CIN) is still found to be the third leading cause of hospital-acquired acute renal insufficiency and it accounts for 11–12% of all hospital-acquired acute renal insufficiency cases [1,2,3]. CIN is reported to have an in-hospital mortality rate of 6–14% in spite of unremitting efforts to prevent its development [1, 2]. It is a predisposing factor for both future kidney function loss and long-term adverse events such as death, stroke, myocardial infarction, and other cardiac and kidney diseases [4, 5]. Previous studies regarding focal liver lesion (FLL) evaluation with the low tube voltage–high tube current technique focused on improving the CNR or lesion conspicuity, rather than on decreasing CM dose [17,18,19,20]

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