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Focal hepatic lesions: contrast-enhancement patterns at pulse-inversion harmonic US using a microbubble contrast agent.

Kim EA, Yoon KH, Lee YH, Kim HW, Juhng SK, Won JJ - Korean J Radiol (2003 Oct-Dec)

Bottom Line: To analyze the contrast-enhancement patterns obtained at pulse-inversion harmonic imaging (PIHI) of focal hepatic lesions, and to thus determine tumor vascularity and the acoustic emission effect.Tumoral vascularity at vascular phase imaging and the acoustic emission effect at delayed phase imaging were each classified as one of four patterns.Contrast-enhancement patterns depicting tumoral vascularity and the acoustic emission effect at PIHI can help differentiate focal hepatic lesions.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology and Institute of Medical Science, Wonkwang University School of Medicine, Jeonbuk, Korea. yoonkh@wmc.wonkwang.ac.kr

ABSTRACT

Objective: To analyze the contrast-enhancement patterns obtained at pulse-inversion harmonic imaging (PIHI) of focal hepatic lesions, and to thus determine tumor vascularity and the acoustic emission effect.

Materials and methods: We reviewed pulse-inversion images in 90 consecutive patients with focal hepatic lesions, namely hepatocellular carcinoma (HCC) (n=43), metastases (n=30), and hemangioma (n=17). Vascular and delayed phase images were obtained immediately and five minutes following the injection of a microbubble contrast agent. Tumoral vascularity at vascular phase imaging and the acoustic emission effect at delayed phase imaging were each classified as one of four patterns.

Results: Vascular phase images depicted internal vessels in 93% of HCCs, marginal vessels in 83% of metastases, and peripheral nodular enhancement in 71% of hemangiomas. Delayed phase images showed inhomogeneous enhancement in 86% of HCCs; hypoechoic, decreased enhancement in 93% of metastases; and hypoechoic and reversed echogenicity in 65% of hemangiomas. Vascular and delayed phase enhancement patterns were associated with a specificity of 91% or greater, and 92% or greater, respectively, and with positive predictive values of 71% or greater, and 85% or greater, respectively.

Conclusion: Contrast-enhancement patterns depicting tumoral vascularity and the acoustic emission effect at PIHI can help differentiate focal hepatic lesions.

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The contrast-enhancement patterns observed at vascular phase pulse-inversion harmonic imaging of hepatic tumors.
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Figure 1: The contrast-enhancement patterns observed at vascular phase pulse-inversion harmonic imaging of hepatic tumors.

Mentions: The reviewers determined the diameters and echogenicity of the tumors, as seen on unenhanced conventional and pre-contrast pulse-inversion harmonic images. The pattern of contrast enhancement of each tumor depicted by dualphase pulse-inversion harmonic US was evaluated by examining the images obtained during the vascular phase of enhancement (typically 20-60 seconds after contrast injection), and during the delayed phase (5 minutes after a separate injection of contrast agent). All observations of enhancement patterns were totally subjective. In each patient, tumoral vascularity of the dominant lesion, as seen on vascular phase images, was classified as one of four patterns, as follows (Fig. 1). The presence of linear or branched internal vessels was categorized as the 'internal vessels' pattern; that of linear or dot-like marginal vessels at the periphery of the tumor, regardless of the presence or absence of central vessels, as the 'marginal vessels' pattern; that of a discrete and well-defined ring of peripheral enhancing nodules, as 'peripheral nodular enhancement'; and the absence of visible vessels or enhancement in either internal or peripheral areas of the tumor, as the 'minimal or no enhancement' pattern. The acoustic emission effect within the tumor, as seen on delayed phase images, was also classified as one of four patterns (Fig. 2). 'Inhomogeneous enhancement' was defined as irregular and heterogeneous enhancement within the tumor; 'hypoechoic, decreased enhancement' as the presence of contrast, but decreased enhancement with respect to adjacent liver parenchyma; 'isoechoic, homogeneous enhancement' as homogeneous enhancement, similar to that of adjacent liver parenchyma; and the term 'hypoechoic and reversed echogenicity' was used to describe a tumor represented as a hyperechoic lesion on unenhanced US images and as a reversed hypoechoic lesion on delayed phase images.


Focal hepatic lesions: contrast-enhancement patterns at pulse-inversion harmonic US using a microbubble contrast agent.

Kim EA, Yoon KH, Lee YH, Kim HW, Juhng SK, Won JJ - Korean J Radiol (2003 Oct-Dec)

The contrast-enhancement patterns observed at vascular phase pulse-inversion harmonic imaging of hepatic tumors.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2698100&req=5

Figure 1: The contrast-enhancement patterns observed at vascular phase pulse-inversion harmonic imaging of hepatic tumors.
Mentions: The reviewers determined the diameters and echogenicity of the tumors, as seen on unenhanced conventional and pre-contrast pulse-inversion harmonic images. The pattern of contrast enhancement of each tumor depicted by dualphase pulse-inversion harmonic US was evaluated by examining the images obtained during the vascular phase of enhancement (typically 20-60 seconds after contrast injection), and during the delayed phase (5 minutes after a separate injection of contrast agent). All observations of enhancement patterns were totally subjective. In each patient, tumoral vascularity of the dominant lesion, as seen on vascular phase images, was classified as one of four patterns, as follows (Fig. 1). The presence of linear or branched internal vessels was categorized as the 'internal vessels' pattern; that of linear or dot-like marginal vessels at the periphery of the tumor, regardless of the presence or absence of central vessels, as the 'marginal vessels' pattern; that of a discrete and well-defined ring of peripheral enhancing nodules, as 'peripheral nodular enhancement'; and the absence of visible vessels or enhancement in either internal or peripheral areas of the tumor, as the 'minimal or no enhancement' pattern. The acoustic emission effect within the tumor, as seen on delayed phase images, was also classified as one of four patterns (Fig. 2). 'Inhomogeneous enhancement' was defined as irregular and heterogeneous enhancement within the tumor; 'hypoechoic, decreased enhancement' as the presence of contrast, but decreased enhancement with respect to adjacent liver parenchyma; 'isoechoic, homogeneous enhancement' as homogeneous enhancement, similar to that of adjacent liver parenchyma; and the term 'hypoechoic and reversed echogenicity' was used to describe a tumor represented as a hyperechoic lesion on unenhanced US images and as a reversed hypoechoic lesion on delayed phase images.

Bottom Line: To analyze the contrast-enhancement patterns obtained at pulse-inversion harmonic imaging (PIHI) of focal hepatic lesions, and to thus determine tumor vascularity and the acoustic emission effect.Tumoral vascularity at vascular phase imaging and the acoustic emission effect at delayed phase imaging were each classified as one of four patterns.Contrast-enhancement patterns depicting tumoral vascularity and the acoustic emission effect at PIHI can help differentiate focal hepatic lesions.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology and Institute of Medical Science, Wonkwang University School of Medicine, Jeonbuk, Korea. yoonkh@wmc.wonkwang.ac.kr

ABSTRACT

Objective: To analyze the contrast-enhancement patterns obtained at pulse-inversion harmonic imaging (PIHI) of focal hepatic lesions, and to thus determine tumor vascularity and the acoustic emission effect.

Materials and methods: We reviewed pulse-inversion images in 90 consecutive patients with focal hepatic lesions, namely hepatocellular carcinoma (HCC) (n=43), metastases (n=30), and hemangioma (n=17). Vascular and delayed phase images were obtained immediately and five minutes following the injection of a microbubble contrast agent. Tumoral vascularity at vascular phase imaging and the acoustic emission effect at delayed phase imaging were each classified as one of four patterns.

Results: Vascular phase images depicted internal vessels in 93% of HCCs, marginal vessels in 83% of metastases, and peripheral nodular enhancement in 71% of hemangiomas. Delayed phase images showed inhomogeneous enhancement in 86% of HCCs; hypoechoic, decreased enhancement in 93% of metastases; and hypoechoic and reversed echogenicity in 65% of hemangiomas. Vascular and delayed phase enhancement patterns were associated with a specificity of 91% or greater, and 92% or greater, respectively, and with positive predictive values of 71% or greater, and 85% or greater, respectively.

Conclusion: Contrast-enhancement patterns depicting tumoral vascularity and the acoustic emission effect at PIHI can help differentiate focal hepatic lesions.

Show MeSH
Related in: MedlinePlus