Hepatic hemangioma: quantitative color power US angiography--facts and fallacies

Liver haemangiomas undetermined at grey-scale ultrasound: contrast-enhancement patterns with SonoVue and pulse-inversion US

The objective of this study was to describe the spectrum of contrast-enhancement patterns of hepatic haemangiomas undetermined at grey-scale ultrasound (US) on SonoVue-enhanced pulse-inversion (PI) US. Twenty patients (11 women, nine men) with 35 haemangiomas (size range: 1-7 cm; mean: 3.1 cm) undetermined at baseline US underwent PI at low M.I. (0.05-0.08) after i.v. injection of SonoVue. All haemangiomas were confirmed by typical helical computed tomography (CT) and/or magnetic resonance imaging (MRI) findings. US examinations were videotaped and then reviewed by two experienced radiologists blinded to the final diagnosis. Readers evaluated by consensus the baseline echogenicity and the dynamic enhancement pattern of each lesion, in comparison with adjacent liver parenchyma. After administration of SonoVue, 31/35 (88%) haemangiomas showed peripheral hyperechoic nodules in the arterial phase, followed by progressive centripetal fill-in, which was complete in 25/35 cases and incomplete in 6/35 cases. Three out of 35 (9%) haemangiomas showed rapid and complete fill-in in the arterial phase, which persisted in the portal and delayed phases. Finally, 1/35 haemangiomas (3%) showed a rim of arterial contrast enhancement with progressive and complete centripetal fill-in in portal-venous and delayed phases. In conclusion, PI after the administration of SonoVue enabled the depiction of typical contrast-enhancement patterns in haemangiomas undetermined at baseline US.

Correlation between color power Doppler sonographic measurement of breast tumor vasculature and immunohistochemical analysis of microvessel density for the quantitation of angiogenesis

OBJECTIVE

To record the correlation between color power Doppler sonographic measurement of breast tumor vasculature and immunohistochemical analysis of microvessel density for the quantitation of angiogenesis.

METHODS

Women with palpable breast masses scheduled for excision biopsy were scanned with two- and three-dimensional color power Doppler sonography before and after the administration of a sonographic contrast agent. Vessel counts were performed on two- and three-dimensional sonographic images before and after contrast agent administration. All tumors were surgically removed and underwent immunohistochemical analysis for microvessel density assessment. The sonographic measure of tumor vascularity was correlated with microvessel density.

RESULTS

Pathologic examination showed 43 breast cancers and 14 benign breast masses. Higher microvessel density was noted in malignant than benign breast masses (P < .0005). Color power Doppler sonographic measurement of tumor vessel number showed a significant positive correlation with tumor size (P < .05) and progesterone receptor negativity (P < .05). A significant positive correlation was observed between microvessel density and the number of intratumoral blood vessels assessed by both two- and three-dimensional color power Doppler sonography (P < .05). Regression models showed three-dimensional color power Doppler sonography to have a significantly higher correlation with microvessel density when compared with two-dimensional color power Doppler sonography at baseline (P < .005). The administration of a sonographic contrast agent did not improve correlation with microvessel density.

CONCLUSIONS

A significant correlation was shown between color power Doppler sonographic measurement of tumor vascularity and microvessel density by immunohistochemical analysis. Further improvement in Doppler sonographic techniques to map capillary vessel flow should be explored to improve the current association with pathologic findings.

Assessment of vascularity in hepatic tumors: comparison of power Doppler sonography and intraarterial CO(2)-enhanced sonography

OBJECTIVE

The purpose of the study was to compare power Doppler sonography with intraarterial CO(2)-enhanced sonography for revealing vascularity in treated and untreated hepatic tumors.

SUBJECTS AND METHODS

Fifty-five patients with 93 liver tumors were prospectively examined with power Doppler sonography and CO(2)-enhanced sonography. These tumors included 29 hepatocellular carcinomas in patients with no previous treatment, 26 treated hepatocellular carcinomas, and 38 hemangiomas. The vascular depiction of power Doppler sonography was compared with that obtained in the early phase of CO(2)-enhanced sonography. The results of angiography were also recorded for comparison.

RESULTS

In the hepatocellular carcinomas, power Doppler sonography was the same as CO(2)-enhanced sonography in 18 (62%) of 29 tumors, was inferior to CO(2)-enhanced sonography in nine (31%) of 29 tumors, and was superior to CO(2)-enhanced sonography in two (7%) of 29 tumors. In the treated hepatocellular carcinomas, power Doppler sonography was the same as CO(2)-enhanced sonography in 15 (58%) of 26 tumors and was inferior in 11 (42%) of 26 tumors. In hemangiomas, the same vascularity was found in both studies in 15 (39%) of 38 tumors, CO(2)-enhanced sonography was superior in 22 (58%) of 38 tumors, and power Doppler sonography was superior in one (3%) of 38 tumors. As a whole, 45% of the 93 tumors showed better vascular depiction on CO(2)-enhanced sonography. However, 19.4% of tumors were hypovascular using power Doppler sonography but hypervascular using CO(2)-enhanced sonography.

CONCLUSION

Power Doppler sonography is a useful technique for screening hepatic tumor vascularity. CO(2)-enhanced sonography is superior to power Doppler sonography in depicting tumor vascularity in treated hepatocellular carcinomas and in hemangiomas, especially small hemangiomas.

Color and power Doppler sonography of liver hemangiomas: a dream unfulfilled?

PURPOSE

The aim of this study was to determine whether color Doppler or power Doppler sonography can aid in the diagnosis of hepatic cavernous hemangiomas.

METHODS

We imaged 25 hepatic cavernous hemangiomas in 17 patients with gray-scale, color Doppler, and power Doppler sonography. Five malignant lesions were also imaged in the same manner for reference. Hemangiomas had been previously diagnosed by biopsy in 8 patients (15 lesions) and by CT, MRI, and/or tagged red blood cell scanning in 9 patients (10 lesions).

RESULTS

Of the 25 hemangiomas, color or power Doppler imaging showed no internal blood flow in 23. Of these 23 lesions, 11 showed a peripheral flow pattern believed to represent flow in displaced blood vessels. This pattern was better visualized with power Doppler imaging in 3 lesions and equally well visualized with color and power Doppler imaging in 8 lesions. Two hemangiomas that had unusual central fibrosis with large vessels in 1 patient showed diffusely increased blood flow on power Doppler study. All 5 malignant lesions showed flow in peripheral vessels, and 1 showed internal vascularity as well.

CONCLUSIONS

Neither color nor power Doppler imaging improved the capability of sonography for making a specific diagnosis of benign hepatic cavernous hemangioma.

Comparison of harmonic and conventional power Doppler ultrasonography for assessment of slow flow in hyperechoic tissue: experimental study using a Doppler phantom

RATIONALE AND OBJECTIVES

Despite the advantages of depicting slow flow in small vessels, conventional power Doppler ultrasound (US) has a basic limitation, specifically that artifactual power Doppler signals mimic blood flow, especially in hyperechoic tissue. The purpose of this study was to compare harmonic power Doppler US with power Doppler US using a Doppler phantom under various parameter settings, focusing on the assessment of slow flow in the hyperechoic tissue.

METHODS

While controlling the flow velocity (5 and 10 cm/s), pulse repetition frequency (500, 700, and 1,000 Hz), wall filter (low and medium), and Doppler gain (90%, 96%, and 100%), the authors performed both harmonic Doppler US and power Doppler US by using a Doppler phantom/flow control system. We measured and compared the relative intensities of the Doppler signals (0-250 scale) in both the vessels and hyperechoic tissue-mimicking materials with the two different imaging modalities.

RESULTS

Power Doppler US with any combination of the four parameters evaluated depicted strong flow signals (mean, 213) that were superior to harmonic Doppler US (mean, 61). Relatively strong artifactual signals within the hyperechoic tissue-mimicking materials were noted on all power Doppler US studies (mean, 106) but nearly none on harmonic Doppler US (mean, 3). The contrast-to-noise ratio of harmonic Doppler US was significantly greater than that of power Doppler US.

CONCLUSIONS

Harmonic Doppler US is more useful in assessing slow flow in hyperechoic tissue than power Doppler US because it produces fewer artifactual Doppler signals originating from stationary hyperechoic tissues, which can be misjudged as true signals on power Doppler US.

Vascularity of hepatocellular carcinoma: assessment with contrast-enhanced second-harmonic versus conventional power Doppler US

PURPOSE

To compare contrast material-enhanced harmonic power Doppler ultrasonography (US) with conventional power Doppler US in depicting the vascularity of hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Twenty patients with nodular HCCs (2.6-13.2 cm in diameter; mean diameter, 4.8 cm) were prospectively examined with both conventional and harmonic power Doppler US. US was performed with a 2-4-MHz curved linear-array transducer according to a standard examination protocol (1,000-Hz pulse repetition frequency, medium wall filter, and power gain of 55%-84% for conventional power Doppler US; 700-Hz pulse repetition frequency, low wall filter, and power gain of 95%-98% for harmonic power Doppler US). Serial, dynamic scans were obtained before intravenous injection of the contrast agent (SH U 508A) and at 30, 60, 90, 120, 180, 240, and 300 seconds after injection with both techniques.

RESULTS

The number of intratumoral power Doppler US signals was similar with both techniques at 30-90 seconds after contrast agent injection; however, after 90 seconds, conventional power Doppler US depicted significantly more signals than did harmonic power Doppler US. Harmonic power Doppler US was superior to conventional power Doppler US in terms of power Doppler artifacts such as "blooming" or motion-related artifacts.

CONCLUSION

Although the effective enhancement duration is relatively short compared with that for conventional power Doppler US, contrast-enhanced harmonic power Doppler US can be effective in evaluating the vascularity of HCCs because of the advantage of fewer power Doppler artifacts.

Hepatic hemangiomas: spectrum of US appearances on gray-scale, power Doppler, and contrast-enhanced US

Because US plays a key role in the initial evaluation of hepatic hemangiomas, knowledge of the entire spectrum of US appearances of these tumors is important. Most hemangiomas have a distinctive US appearance, and even with those with atypical appearances on conventional gray-scale US, specific diagnoses can be made using pulse-inversion harmonic US with contrast agents. In this essay, we review the spectrum of US appearances of hepatic hemangiomas on conventional gray-scale, power Doppler, and pulse-inversion harmonic US with contrast agents.

Doppler sonography of the native liver

Doppler sonography is being used routinely in evaluating the vascular structures of the native liver because of its ease of use, lower cost, easier availability, lack of need for X-ray and accuracy. Doppler sonography can well demonstrate the vascularization of liver tumors, portal vein thrombosis, portal vein abnormalities in patients with portal hypertension and hepatic venous findings in patients with Budd Chiari syndrome. The purpose of this article is to present information about Doppler sonography of the native liver and to show its usefulness in the evaluation of hepatic vascular diseases.

Signal from hepatic hemangiomas on power Doppler US: real or artefactual?

To describe imaging findings of hepatic hemangiomas on power Doppler (PD) ultrasound (US) with revised Doppler parameters for preventing PD artefacts from stationary hyperechoic tissue, we prospectively evaluated 48 hemangiomas by PD US with predetermined PD settings to prevent artefactual signals from stationary hyperechoic tissue (pulse repetition frequency of 1000 Hz, medium wall filter, and PD gain of 60-85%). Intratumoral PD signals were not seen in 32 lesions (67%). Minimal (n = 15) or moderate (n = 1) intratumoral PD signals were seen in 16 lesions (33%) and were distributed in the peripheral portion only in 12 lesions (75%) and in the peripheral and central portion in 4 lesions (25%). Due to the lack of sensitivity of PD to detect slow flow in hemangiomas, PD US should no longer be used for the evaluation of echogenic liver masses caused by hemangiomas from other hypovascular malignant lesions of the liver.