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Separation of hepatic iron and fat by dual-source dual-energy computed tomography based on material decomposition: an animal study.

Ma J, Song ZQ, Yan FH - PLoS ONE (2014)

Bottom Line: Spearman's correlation and one-way analysis of variance (ANOVA) were performed, respectively, to analyze statistically the correlations with the histopathological results and differences among groups.Different groups showed significantly different iron enhancement values and VNC values (F = 25.308,p<0.001; F = 10.911, p<0.001, respectively).Among the groups, significant differences in iron enhancement values were only observed between the iron-present and iron-absent groups, and differences in VNC values were only observed between the fat-present and fat-absent groups.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Shanghai Zhongshan Hospital, Shanghai Medical College, Fudan University, Shanghai, China; Department of Radiology, the 2nd Affiliated Hospital of Shi-Hezi University Medical School (Corps Hospital), Urumqi, Xinjiang Province, China.

ABSTRACT

Objective: To explore the feasibility of dual-source dual-energy computed tomography (DSDECT) for hepatic iron and fat separation in vivo.

Materials and methods: All of the procedures in this study were approved by the Research Animal Resource Center of Shanghai Ruijin Hospital. Sixty rats that underwent DECT scanning were divided into the normal group, fatty liver group, liver iron group, and coexisting liver iron and fat group, according to Prussian blue and HE staining. The data for each group were reconstructed and post-processed by an iron-specific, three-material decomposition algorithm. The iron enhancement value and the virtual non-iron contrast value, which indicated overloaded liver iron and residual liver tissue, respectively, were measured. Spearman's correlation and one-way analysis of variance (ANOVA) were performed, respectively, to analyze statistically the correlations with the histopathological results and differences among groups.

Results: The iron enhancement values were positively correlated with the iron pathology grading (r = 0.729, p<0.001). Virtual non-iron contrast (VNC) values were negatively correlated with the fat pathology grading (r = -0.642,p<0.0001). Different groups showed significantly different iron enhancement values and VNC values (F = 25.308,p<0.001; F = 10.911, p<0.001, respectively). Among the groups, significant differences in iron enhancement values were only observed between the iron-present and iron-absent groups, and differences in VNC values were only observed between the fat-present and fat-absent groups.

Conclusion: Separation of hepatic iron and fat by dual energy material decomposition in vivo was feasible, even when they coexisted.

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Related in: MedlinePlus

Example of a normal group rat liver.The rat liver periphery is outlined with a black line. The attenuation of the normal rat liver on a general view is homogeneous (CT value is 68 HU). On the VIC image, there are no red dots to show iron (iron enhancement value is −21.31 HU, VNC value is 71.85 HU) (a–b). Example of a rat in the fatty liver group. The rat liver on a general view had mildly lower density (CT value is 52.78 HU). On the VIC image, there are no red dots for iron (iron enhancement value is −13.20 HU, VNC value is 50.22 HU) (c–d). A typical image of a rat in the coexisting iron and fat group. Coincidentally, the dominant iron deposition region (outlined) is separated from the steatosis infiltration dominant region (*). The rat liver on a general view is inhomogeneous. Regions showing higher density might have been caused mainly by iron deposition (CT value is 83.72 HU). Regions showing lower density might be dominated by fat infiltration (CT value is 47.84 HU). On the VIC image, the red regions represent the presence of iron, corresponding to high-density regions on a general view image (iron enhancement value is 23.42 HU) (e–f). The color-absent region is also in accordance with the low-density region on the general view image (VNC value is 43.58 HU). Example of a rat in the liver iron group. The rat liver on general viewing showed mildly higher density (CT value is 80.35 HU). On the VIC image, there are scattered red dots that represent the presence of iron (iron enhancement value is 4.27 HU; VNC value is 72.35 HU) (g–h).
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pone-0110964-g005: Example of a normal group rat liver.The rat liver periphery is outlined with a black line. The attenuation of the normal rat liver on a general view is homogeneous (CT value is 68 HU). On the VIC image, there are no red dots to show iron (iron enhancement value is −21.31 HU, VNC value is 71.85 HU) (a–b). Example of a rat in the fatty liver group. The rat liver on a general view had mildly lower density (CT value is 52.78 HU). On the VIC image, there are no red dots for iron (iron enhancement value is −13.20 HU, VNC value is 50.22 HU) (c–d). A typical image of a rat in the coexisting iron and fat group. Coincidentally, the dominant iron deposition region (outlined) is separated from the steatosis infiltration dominant region (*). The rat liver on a general view is inhomogeneous. Regions showing higher density might have been caused mainly by iron deposition (CT value is 83.72 HU). Regions showing lower density might be dominated by fat infiltration (CT value is 47.84 HU). On the VIC image, the red regions represent the presence of iron, corresponding to high-density regions on a general view image (iron enhancement value is 23.42 HU) (e–f). The color-absent region is also in accordance with the low-density region on the general view image (VNC value is 43.58 HU). Example of a rat in the liver iron group. The rat liver on general viewing showed mildly higher density (CT value is 80.35 HU). On the VIC image, there are scattered red dots that represent the presence of iron (iron enhancement value is 4.27 HU; VNC value is 72.35 HU) (g–h).

Mentions: The iron enhancement values were significantly different among the groups (F = 25.308, p<0.001) (Figure 4). The following significant differences in iron content were observed: normal group vs coexisting group (p<0.001), normal group vs liver iron group (p<0.001), fatty liver group vs coexisting group (p<0.001), and fatty liver group vs liver iron group (p<0.001). The iron enhancement values of the iron-present groups were larger than 0 Housefield units (HU), while the absent groups were negative (<0 HU). Iron presence was visible on VIC imaging for both the liver iron and coexisting groups (Figure 5).


Separation of hepatic iron and fat by dual-source dual-energy computed tomography based on material decomposition: an animal study.

Ma J, Song ZQ, Yan FH - PLoS ONE (2014)

Example of a normal group rat liver.The rat liver periphery is outlined with a black line. The attenuation of the normal rat liver on a general view is homogeneous (CT value is 68 HU). On the VIC image, there are no red dots to show iron (iron enhancement value is −21.31 HU, VNC value is 71.85 HU) (a–b). Example of a rat in the fatty liver group. The rat liver on a general view had mildly lower density (CT value is 52.78 HU). On the VIC image, there are no red dots for iron (iron enhancement value is −13.20 HU, VNC value is 50.22 HU) (c–d). A typical image of a rat in the coexisting iron and fat group. Coincidentally, the dominant iron deposition region (outlined) is separated from the steatosis infiltration dominant region (*). The rat liver on a general view is inhomogeneous. Regions showing higher density might have been caused mainly by iron deposition (CT value is 83.72 HU). Regions showing lower density might be dominated by fat infiltration (CT value is 47.84 HU). On the VIC image, the red regions represent the presence of iron, corresponding to high-density regions on a general view image (iron enhancement value is 23.42 HU) (e–f). The color-absent region is also in accordance with the low-density region on the general view image (VNC value is 43.58 HU). Example of a rat in the liver iron group. The rat liver on general viewing showed mildly higher density (CT value is 80.35 HU). On the VIC image, there are scattered red dots that represent the presence of iron (iron enhancement value is 4.27 HU; VNC value is 72.35 HU) (g–h).
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pone-0110964-g005: Example of a normal group rat liver.The rat liver periphery is outlined with a black line. The attenuation of the normal rat liver on a general view is homogeneous (CT value is 68 HU). On the VIC image, there are no red dots to show iron (iron enhancement value is −21.31 HU, VNC value is 71.85 HU) (a–b). Example of a rat in the fatty liver group. The rat liver on a general view had mildly lower density (CT value is 52.78 HU). On the VIC image, there are no red dots for iron (iron enhancement value is −13.20 HU, VNC value is 50.22 HU) (c–d). A typical image of a rat in the coexisting iron and fat group. Coincidentally, the dominant iron deposition region (outlined) is separated from the steatosis infiltration dominant region (*). The rat liver on a general view is inhomogeneous. Regions showing higher density might have been caused mainly by iron deposition (CT value is 83.72 HU). Regions showing lower density might be dominated by fat infiltration (CT value is 47.84 HU). On the VIC image, the red regions represent the presence of iron, corresponding to high-density regions on a general view image (iron enhancement value is 23.42 HU) (e–f). The color-absent region is also in accordance with the low-density region on the general view image (VNC value is 43.58 HU). Example of a rat in the liver iron group. The rat liver on general viewing showed mildly higher density (CT value is 80.35 HU). On the VIC image, there are scattered red dots that represent the presence of iron (iron enhancement value is 4.27 HU; VNC value is 72.35 HU) (g–h).
Mentions: The iron enhancement values were significantly different among the groups (F = 25.308, p<0.001) (Figure 4). The following significant differences in iron content were observed: normal group vs coexisting group (p<0.001), normal group vs liver iron group (p<0.001), fatty liver group vs coexisting group (p<0.001), and fatty liver group vs liver iron group (p<0.001). The iron enhancement values of the iron-present groups were larger than 0 Housefield units (HU), while the absent groups were negative (<0 HU). Iron presence was visible on VIC imaging for both the liver iron and coexisting groups (Figure 5).

Bottom Line: Spearman's correlation and one-way analysis of variance (ANOVA) were performed, respectively, to analyze statistically the correlations with the histopathological results and differences among groups.Different groups showed significantly different iron enhancement values and VNC values (F = 25.308,p<0.001; F = 10.911, p<0.001, respectively).Among the groups, significant differences in iron enhancement values were only observed between the iron-present and iron-absent groups, and differences in VNC values were only observed between the fat-present and fat-absent groups.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Shanghai Zhongshan Hospital, Shanghai Medical College, Fudan University, Shanghai, China; Department of Radiology, the 2nd Affiliated Hospital of Shi-Hezi University Medical School (Corps Hospital), Urumqi, Xinjiang Province, China.

ABSTRACT

Objective: To explore the feasibility of dual-source dual-energy computed tomography (DSDECT) for hepatic iron and fat separation in vivo.

Materials and methods: All of the procedures in this study were approved by the Research Animal Resource Center of Shanghai Ruijin Hospital. Sixty rats that underwent DECT scanning were divided into the normal group, fatty liver group, liver iron group, and coexisting liver iron and fat group, according to Prussian blue and HE staining. The data for each group were reconstructed and post-processed by an iron-specific, three-material decomposition algorithm. The iron enhancement value and the virtual non-iron contrast value, which indicated overloaded liver iron and residual liver tissue, respectively, were measured. Spearman's correlation and one-way analysis of variance (ANOVA) were performed, respectively, to analyze statistically the correlations with the histopathological results and differences among groups.

Results: The iron enhancement values were positively correlated with the iron pathology grading (r = 0.729, p<0.001). Virtual non-iron contrast (VNC) values were negatively correlated with the fat pathology grading (r = -0.642,p<0.0001). Different groups showed significantly different iron enhancement values and VNC values (F = 25.308,p<0.001; F = 10.911, p<0.001, respectively). Among the groups, significant differences in iron enhancement values were only observed between the iron-present and iron-absent groups, and differences in VNC values were only observed between the fat-present and fat-absent groups.

Conclusion: Separation of hepatic iron and fat by dual energy material decomposition in vivo was feasible, even when they coexisted.

Show MeSH
Related in: MedlinePlus