Contrast-enhanced 3D ultrasound provides a spatial perspective for liver tumor enhancement, and could help in differentiating focal liver lesions, said Kazushi Numata, MD, from the Gastroenterological Center at Yokohama City University Medical Center in Kanagawa, Japan, and colleagues.
The study, published in the May issue of the World Journal of Gastroenterology, sought to observe whether 3D ultrasonography with a perflubutane-based contrast agent could differentiate focal liver lesions based on enhancement patterns, as 2D ultrasonagraphy has been used widely in the clinical diagnosis of liver lesions, explained the authors.
Numata and colleagues recruited 282 patients presenting with focal liver lesions, including 168 hepatocellular carcinomas (HCCs), 63 metastases, 40 hemangiomas and 11 focal nodular hyperplasias (FNHs) for inclusion in their research. Each patient underwent a 3D ultrasound scan with perflubutane-based contrast agent and tomographic ultrasound images and sonographic angiograms were reconstructed.
Between January 2007 and October 2007, enhancement patterns of 163 of the 282 lesions were analyzed retrospectively. From November 2007 to May 2008, 119 lesions were compared to contrast-enhanced 2D ultrasound by way of 3D ultrasound scanning, for a potential differential diagnosis, they reported.
The authors found that the 3D view allowed for dominant enhancement patterns to be revealed as “diffuse enhancement or peripheral ring-like enhancement, followed with washout change for HCCs or metastases and peripheral nodular enhancement or diffuse enhancement with spoke-wheel arteries, followed by persistent enhancement for hemangiomas or FNHs, respectively."
According to the researchers, the prospective differentiation of lesions had an average overall sensitivity result of 92 percent for the two readers of the imaging studies and an overall specificity result of 91 percent. The sensitivity and specificity for HCCs was 84 and 97 percent, for metastases, 91 and 98 percent and for hemangiomas and FNHs, 80 and 99 percent, respectively.
In addition, good to excellent inter-reader agreement was achieved, said Numata and colleagues.
While the results of the study indicate that contrast-enhanced 3D ultrasound can exhibit the characteristic enhancement of HCC tumors objectively, the authors concluded: “No significant difference exists between prospective diagnosis accuracy at contrast-enhanced 3D ultrasound and that at contrast-enhanced 2D ultrasound.”