Review
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World J Gastroenterol. Aug 7, 2014; 20(29): 9998-10007
Published online Aug 7, 2014. doi: 10.3748/wjg.v20.i29.9998
Liver metastases: Contrast-enhanced ultrasound compared with computed tomography and magnetic resonance
Vito Cantisani, Hektor Grazhdani, Cristina Fioravanti, Maria Rosignuolo, Fabrizio Calliada, Daniela Messineo, Maria Giulia Bernieri, Adriano Redler, Carlo Catalano, Ferdinando D’Ambrosio
Vito Cantisani, Hektor Grazhdani, Cristina Fioravanti, Maria Rosignuolo, Daniela Messineo, Maria Giulia Bernieri, Adriano Redler, Carlo Catalano, Ferdinando D’Ambrosio, Department of Radiology, Oncology and Anatomo-Pathology “Sapienza” University of Rome, 00161 Rome, Italy
Adriano Redler, Department of Surgical Sciences, Sapienza University of Rome, Rome, Italy
Fabrizio Calliada, Department of Radiology, University of Pavia, 27100 Pavia, Italy
Author contributions: Cantisani V, Grazhdani H, Calliada F provided substantial contributions to analysis of the literature, conception, design and writing the paper; Fioravanti C, Rosignuolo M, Messineo D and Bernieri MG drafted the article and revised it critically for important intellectual content; Redler A, Catalano C and D’Ambrosio F provided final revision and approval.
Correspondence to: Vito Cantisani, MD, PhD, Department of Radiology, Oncology and Anatomo-Pathology “Sapienza” University of Rome, Viale Regina Elena, 324, 00161 Rome, Italy. vito.cantisani@uniroma1.it
Telephone: +39-34-71743847  Fax: +39-6-490243
Received: September 29, 2013
Revised: November 23, 2013
Accepted: April 27, 2014
Published online: August 7, 2014
Abstract

The development of ultrasound contrast agents with excellent tolerance and safety profiles has notably improved liver evaluation with ultrasound (US) for several applications, especially for the detection of metastases. In particular, contrast enhanced ultrasonography (CEUS) allows the display of the parenchymal microvasculature, enabling the study and visualization of the enhancement patterns of liver lesions in real time and in a continuous manner in all vascular phases, which is similar to contrast-enhanced computed tomography (CT) and contrast-enhanced magnetic resonance imaging. Clinical studies have reported that the use of a contrast agent enables the visualization of more metastases with significantly improved sensitivity and specificity compared to baseline-US. Furthermore, studies have shown that CEUS yields sensitivities comparable to CT. In this review, we describe the state of the art of CEUS for detecting colorectal liver metastases, the imaging features, the literature reports of metastases in CEUS as well as its technique, its clinical role and its potential applications. Additionally, the updated international consensus panel guidelines are reported in this review with the inherent limitations of this technique and best practice experiences.

Keywords: Ultrasound, Contrast enhanced ultrasound, Ultrasound contrast agent, Colorectal cancer, Colorectal liver metastases, Magnetic resonance imaging, Computed tomography, 18F-fluorodeoxyglucose positron emission tomography, Intraoperative ultrasound

Core tip: Contrast enhanced ultrasound has completely changed the ultrasound liver imaging of the colorectal cancer patient, notably increasing its sensitivity and accuracy in metastases detection. Clinical studies have reported that the use of a contrast agent enables the visualization of more metastases with significantly improved sensitivity and specificity compared to baseline-ultrasound. Furthermore, studies have shown that contrast enhanced ultrasound yields sensitivities comparable to computed tomography. In this review, we describe the state of the art of this technique.