Contrast-Enhanced Ultrasound (CEUS) in the Diagnostic Algorithm of Hepatocellular and Cholangiocellular Carcinoma, Comments on the AASLD Guidelines

Abstract

Contrast-enhanced ultrasound (CEUS) has long been present in important guidelines and recommendations for the diagnostic work-up of focal liver lesions in patients with cirrhosis. These guidelines have included the guidelines of the American Association for the Study of Liver Diseases (AASLD) 2005, the Asian Pacific Association for the Study of the Liver consensus recommendations on hepatocellular carcinoma, the recommendations of the Japanese Society of Hepatology, and the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) guidelines 2004, 2008 and 2012 (in preparation). Recently, the AASLD removed CEUS from their guidelines in part because of the perceived possibility of false-positive hepatocellular carcinoma (HCC) diagnosis in patients with intrahepatic cholangiocarcinoma (ICC), and in part because CEUS is not available in the USA. This latter factor means that published results are not entirely applicable to a North American population. The present manuscript discusses the diagnostic algorithm of hepatocellular carcinoma and provides information on the differential diagnosis between HCC and ICC.

Detection and characterization of small superficially located focal liver lesions by contrast-enhanced ultrasound with high frequency transducers

“…Conventional BMUS with low frequency convex transducer (1)(2)(3)(4)(5) is the first line imaging method for detecting and diagnosis of FLLs [4,5]. Assessing the liver surface nodularity using low frequency BMUS has specificity up to 95% [24] and a sensitivity of up to 91.1% indicative for cirrhosis [25].…”

“…Early detection and accurate characterization of small focal liver lesions (FLLs) is crucial for an optimal curative treatment, which allows successful tumor surgery or radiofrequency ablation (RFA) with real-time ultrasound guidance [1][2][3].…”

“…Over the last decade, with the wide clinical application of microbubble ultrasound contrast agents, contrastenhanced ultrasound (CEUS) has noticeably improved the identification and characterization of FLLs, especially for FLLs less than 10 mm in size [7][8][9][10][11][12]. However, it still proves to be difficult to differentiate malignant and benign FLLs, especially when the lesion is smaller than 10 mm or located superficially [2,13].…”

“…Compared to the usual low frequency convex transducers (1)(2)(3)(4)(5), the utilization of high frequency 7 to 9 MHz (or even higher) transducers offers important advantages such as high resolution and near field investigations. These transducers have been primarily used in transabdominal ultrasound examinations to improve the detection of liver surface nodularity [14][15][16] or for the detection of small FLLs as deep as 4 to 5 cm [17].…”

“…Initial studies using dynamic CEUS with multifrequency matrix probes have indicated a high diagnostic value for the evaluation of tumor microvascularization in animal experiments [19,20]. Recent publications in intra-operative CEUS with high frequency transducers exhibited high diagnostic potential for the detection and differentiation between benign and malignant FLLs [2,[11][12][13]21], particularly for liver lesions less than 10 mm. The detection rate was comparable to pre-operative contrast enhanced spiral computer tomography (ceCT) and contrast enhanced magnetic resonance imaging (ceMRI) [3,17].…”