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Characterization of focal liver lesions with superparamagnetic iron oxide-enhanced MR imaging: value of distributional phase T1-weighted imaging.

Lee JM, Kim CS, Youk JH, Lee MS - Korean J Radiol (2003 Jan-Mar)

Bottom Line: Postcontrast T1-weighted imaging was performed within eight minutes of infusion of the contrast medium (distributional phase).Both qualitative and quantitative analysis was performed.T1-weighted double-echo FLASH images obtained soon after the infusion of ferumoxides, show characteristic enhancement patterns and improved the differentiation of focal liver lesions.

View Article: PubMed Central - PubMed

Affiliation: Department of Diagnostic Radiology, Seoul National University Hospital, Korea. leejm@radcom.snu.ac.kr

ABSTRACT

Objective: To determine the potential value of distributional-phase T1-weighted ferumoxides-enhanced magnetic resonance (MR) imaging for tissue characterization of focal liver lesions.

Materials and methods: Ferumoxides-enhanced MR imaging was performed using a 1.5-T system in 46 patients referred for evaluation of known or suspected hepatic malignancies. Seventy-three focal liver lesions (30 hepatocellular carcinomas (HCC), 12 metastases, 15 cysts, 13 hemangiomas, and three cholangiocarcinomas) were evaluated. MR imaging included T1-weighted double-echo gradient-echo (TR/TE: 150/4.2 and 2.1 msec), T2*-weighted gradient-echo (TR/TE: 180/12 msec), and T2-weighted turbo spin-echo MR imaging at 1.5 T before and after intravenous administration of ferumoxides (15 mmol/kg body weight). Postcontrast T1-weighted imaging was performed within eight minutes of infusion of the contrast medium (distributional phase). Both qualitative and quantitative analysis was performed.

Results: During the distributional phase after infusion of ferumoxides, unique enhancement patterns of focal liver lesions were observed for hemangiomas, metastases, and hepatocellular carcinomas. On T1-weighted GRE images obtained during the distributional phase, hemangiomas showed a typical positive enhancement pattern of increased signal; metastases showed ring enhancement; and hepatocellar carcinomas showed slight enhancement. Quantitatively, the signal-to-noise ratio of hemangiomas was much higher than that of other tumors (p <.05) and was similar to that of intrahepatic vessels. This finding permitted more effective differentiation between hemangiomas and other malignant tumors.

Conclusion: T1-weighted double-echo FLASH images obtained soon after the infusion of ferumoxides, show characteristic enhancement patterns and improved the differentiation of focal liver lesions.

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A 65-year-old man with biopsy-proven hepatocellular carcinoma in the right lobe of the liver.A. Precontrast T1-weighted out-of-phase gradient-echo image depicts a hyperintense tumor (arrow) with a hypointense capsule in the right lobe of the liver.B. Postcontrast T1-weighted out-of-phase gradient-echo image obtained during the distributional phase shows that the lesion (arrow) is hyperintense compared to the liver, but much less hyperintense than the branches of the intrahepatic portal vein (open arrows).C. Postcontrast T1 in-phase gradient-echo image obtained during the distributional phase shows that the lesion (arrow) has become more hyperintense than the liver but is still less hyperintense than the branches of the portal vein (open arrows). Note the presence of multiple hypointense regenerating nodules in the liver parenchyma.D. Postcontrast T2*-weighted gradient echo image shows markedly improved lesion (arrow)-to-liver contrast due to the substantially decreased liver parenchymal signal.
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Figure 4: A 65-year-old man with biopsy-proven hepatocellular carcinoma in the right lobe of the liver.A. Precontrast T1-weighted out-of-phase gradient-echo image depicts a hyperintense tumor (arrow) with a hypointense capsule in the right lobe of the liver.B. Postcontrast T1-weighted out-of-phase gradient-echo image obtained during the distributional phase shows that the lesion (arrow) is hyperintense compared to the liver, but much less hyperintense than the branches of the intrahepatic portal vein (open arrows).C. Postcontrast T1 in-phase gradient-echo image obtained during the distributional phase shows that the lesion (arrow) has become more hyperintense than the liver but is still less hyperintense than the branches of the portal vein (open arrows). Note the presence of multiple hypointense regenerating nodules in the liver parenchyma.D. Postcontrast T2*-weighted gradient echo image shows markedly improved lesion (arrow)-to-liver contrast due to the substantially decreased liver parenchymal signal.

Mentions: In terms of the relative signal intensity of focal liver lesions observed at T1-weighted double-echo GRE imaging, out-of-phase images obtained using minimum echo time better differentiated hemangiomas from other tumors than did in-phase images (Table 1). Distributional-phase T1-weighted out-of-phase imaging showed that no hemangioma was hypointense, but 11 of 12 metastatic lesions (92%) and three cholangiocarcinomas (100%) were (Table 1). This same modality showed that 19 of 30 HCCs (63%) were hypointense, but nine HCCs seen as hyperintense at precontrast T1-weighted imaging were also seen as hyperintense on all ferumoxides-enhanced T1-weighted out-of-phase images because liver parenchyma showed a signal decrease after the infusion of ferumoxides (Fig. 4) (Table 1).


Characterization of focal liver lesions with superparamagnetic iron oxide-enhanced MR imaging: value of distributional phase T1-weighted imaging.

Lee JM, Kim CS, Youk JH, Lee MS - Korean J Radiol (2003 Jan-Mar)

A 65-year-old man with biopsy-proven hepatocellular carcinoma in the right lobe of the liver.A. Precontrast T1-weighted out-of-phase gradient-echo image depicts a hyperintense tumor (arrow) with a hypointense capsule in the right lobe of the liver.B. Postcontrast T1-weighted out-of-phase gradient-echo image obtained during the distributional phase shows that the lesion (arrow) is hyperintense compared to the liver, but much less hyperintense than the branches of the intrahepatic portal vein (open arrows).C. Postcontrast T1 in-phase gradient-echo image obtained during the distributional phase shows that the lesion (arrow) has become more hyperintense than the liver but is still less hyperintense than the branches of the portal vein (open arrows). Note the presence of multiple hypointense regenerating nodules in the liver parenchyma.D. Postcontrast T2*-weighted gradient echo image shows markedly improved lesion (arrow)-to-liver contrast due to the substantially decreased liver parenchymal signal.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Figure 4: A 65-year-old man with biopsy-proven hepatocellular carcinoma in the right lobe of the liver.A. Precontrast T1-weighted out-of-phase gradient-echo image depicts a hyperintense tumor (arrow) with a hypointense capsule in the right lobe of the liver.B. Postcontrast T1-weighted out-of-phase gradient-echo image obtained during the distributional phase shows that the lesion (arrow) is hyperintense compared to the liver, but much less hyperintense than the branches of the intrahepatic portal vein (open arrows).C. Postcontrast T1 in-phase gradient-echo image obtained during the distributional phase shows that the lesion (arrow) has become more hyperintense than the liver but is still less hyperintense than the branches of the portal vein (open arrows). Note the presence of multiple hypointense regenerating nodules in the liver parenchyma.D. Postcontrast T2*-weighted gradient echo image shows markedly improved lesion (arrow)-to-liver contrast due to the substantially decreased liver parenchymal signal.
Mentions: In terms of the relative signal intensity of focal liver lesions observed at T1-weighted double-echo GRE imaging, out-of-phase images obtained using minimum echo time better differentiated hemangiomas from other tumors than did in-phase images (Table 1). Distributional-phase T1-weighted out-of-phase imaging showed that no hemangioma was hypointense, but 11 of 12 metastatic lesions (92%) and three cholangiocarcinomas (100%) were (Table 1). This same modality showed that 19 of 30 HCCs (63%) were hypointense, but nine HCCs seen as hyperintense at precontrast T1-weighted imaging were also seen as hyperintense on all ferumoxides-enhanced T1-weighted out-of-phase images because liver parenchyma showed a signal decrease after the infusion of ferumoxides (Fig. 4) (Table 1).

Bottom Line: Postcontrast T1-weighted imaging was performed within eight minutes of infusion of the contrast medium (distributional phase).Both qualitative and quantitative analysis was performed.T1-weighted double-echo FLASH images obtained soon after the infusion of ferumoxides, show characteristic enhancement patterns and improved the differentiation of focal liver lesions.

View Article: PubMed Central - PubMed

Affiliation: Department of Diagnostic Radiology, Seoul National University Hospital, Korea. leejm@radcom.snu.ac.kr

ABSTRACT

Objective: To determine the potential value of distributional-phase T1-weighted ferumoxides-enhanced magnetic resonance (MR) imaging for tissue characterization of focal liver lesions.

Materials and methods: Ferumoxides-enhanced MR imaging was performed using a 1.5-T system in 46 patients referred for evaluation of known or suspected hepatic malignancies. Seventy-three focal liver lesions (30 hepatocellular carcinomas (HCC), 12 metastases, 15 cysts, 13 hemangiomas, and three cholangiocarcinomas) were evaluated. MR imaging included T1-weighted double-echo gradient-echo (TR/TE: 150/4.2 and 2.1 msec), T2*-weighted gradient-echo (TR/TE: 180/12 msec), and T2-weighted turbo spin-echo MR imaging at 1.5 T before and after intravenous administration of ferumoxides (15 mmol/kg body weight). Postcontrast T1-weighted imaging was performed within eight minutes of infusion of the contrast medium (distributional phase). Both qualitative and quantitative analysis was performed.

Results: During the distributional phase after infusion of ferumoxides, unique enhancement patterns of focal liver lesions were observed for hemangiomas, metastases, and hepatocellular carcinomas. On T1-weighted GRE images obtained during the distributional phase, hemangiomas showed a typical positive enhancement pattern of increased signal; metastases showed ring enhancement; and hepatocellar carcinomas showed slight enhancement. Quantitatively, the signal-to-noise ratio of hemangiomas was much higher than that of other tumors (p <.05) and was similar to that of intrahepatic vessels. This finding permitted more effective differentiation between hemangiomas and other malignant tumors.

Conclusion: T1-weighted double-echo FLASH images obtained soon after the infusion of ferumoxides, show characteristic enhancement patterns and improved the differentiation of focal liver lesions.

Show MeSH
Related in: MedlinePlus