Virtual unenhanced imaging of the liver derived from 160-mm rapid-switching dual-energy CT (rsDECT): Comparison of the accuracy of attenuation values and solid liver lesion conspicuity with native unenhanced images

Objectives: To explore the correlation between fatty content of fatty liver and the difference of CT attenuation value in dual-energy CT, and to evaluate the value of dual-energy CT in the quantitative diagnosis of fatty liver in rabbits. Material and Methods: Dual-energy CT at 120 kVp and 90 kVp was performed in 16 rabbits of experimental groups that were induced to various degrees of fatty liver by feeding carbon tetrachloride (CCl4). Four healthy rabbits in the control group underwent dual-energy CT at the same time. The CT attenuation values of liver tissues at 120 kVp (H120), 90 kVp (H90) and the difference (ΔH) between them were obtained. The specimens of liver tissues were examined with freeze section (9 μm) and an oil red O stain histologically. The ratio of fatty content in liver to the liver volume (VP value) was measured using the image analyzer system. Results: The change of CT attenuation values between 120 kVp and 90 kVp was not obvious (ΔH between −0.4 HU and 1.4 HU) in the control group. The density of the liver in the experimental groups decreased differently, and the change in CT attenuation values between high and low energy levels were very clear. H120 values were between 51.0 HU and 91.7 HU and H90 values were between 37.0 HU and 89.2 HU. ΔH values were between 2.5 HU and 14.0 HU. Significant negative linear correlation ( r = −0.92, −0.93, t = 8.51, 9.76, p < 0.001, 0.001, respectively) were found between VP values and H120 and H90, respectively, while significant positive linear correlation ( r = 0.95, t = 11.89, p < 0.001) was found between VP values and ΔH. Conclusion: The amount and degree of fat in the fatty liver can be assessed exactly by dual-energy CT. It will be a potential new effective method for quantitative diagnosis of fatty livers.

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Dual-energy CT to differentiate gallbladder polyps: cholesterol versus adenomatous

Acta Radiologica ◽

10.1177/0284185120916202 ◽

2020 ◽

pp. 028418512091620

Author(s):

Sheng Nan Yin ◽

Jing Chi ◽

Li Liu ◽

Ning Ding ◽

Yi Ding Ji ◽

...

Keyword(s):

Dual Energy ◽

Adenomatous Polyps ◽

Ct Scans ◽

Dual Energy Ct ◽

Ct Image ◽

Gallbladder Polyps ◽

Attenuation Value ◽

The Mean ◽

Value Changes ◽

Attenuation Values

Background Dual-energy computed tomography (DE-CT) scans were acquired to identify cholesterol and adenomatous gallbladder (GB) polyps, which have not been well evaluated before surgery. Purpose To evaluate the DE-CT findings of GB polyps 1.0–2.0 cm in size and differentiate between cholesterol and adenomatous polyps. Material and Methods Forty-six patients with GB polyps were surgically treated from December 2017 to December 2019 and divided into two groups according to their postoperative pathologic results: a cholesterol group with 26 patients and an adenomatous group with 20 patients. All of these patients underwent DE-CT imaging with tube voltages of 80 kVp and 140 kVp within two weeks before surgery. Mean attenuation values were measured for every GB polyp at 80/140 kVp and at 40/140 keV. The mean attenuation value changes between 140 kVp and 80 kVp (MAVC140–80 kVp) and mean attenuation value changes between 100 keV and 40 keV (MAVC100–40 keV) were calculated. Results The CT image parameters of all 46 patients with GB polyps were analyzed. There were significant differences in MAVC140–80 kVp and MAVC100–40 keV between cholesterol and adenomatous polyps ( P <0.05); these values were positive for cholesterol polyps and negative for adenomatous polyps. Conclusion The unique energy spectrum information provided by DE-CT scans is helpful in differentiating between cholesterol and adenomatous polyps 1.0–2.0 cm in size.

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