The EFSUMB guidelines for contrast-enhanced ultrasound are comprehensive and informative for good clinical practice: will radiologists take the lead?

Abstract

A study group organized by the European Federation of Societies of Ultrasound in Medicine and Biology (EFSUMB) has issued an up-to-date set of guidelines on the clinical application of contrast-enhanced ultrasound (CEUS) [1]. The first set of guidelines for the application of contrast agents to the practice of ultrasound were published in 2004 [2], and the present set of guidelines are directed towards those not intimately involved in the field, whose perception is that rapid advances in technology and techniques can be difficult to follow, as well as experienced users of CEUS. The initial guidelines concentrated on CEUS applications in the liver, but the present guidelines recognize the expanding role of CEUS and include recommendations for its use in (i) the kidney, (ii) vesicoureteric reflux, (iii) the pancreas, (iv) trauma and (v) the cerebral circulation. The guidelines include good clinical practice recommendations for the use of CEUS, and are exceptionally comprehensive without being lengthy. Detailed descriptions of the procedure techniques, the interpretation of findings and its limitations are included. The study group readily acknowledge the shortcomings of a CEUS examination; these are the exact limitations that occur with all ultrasound examinations. When the baseline ultrasound examination is disappointing, then the CEUS examination is also likely to disappoint — an important caveat for those incorporating techniques of CEUS into their practice. Recommendations for investigator training are also included, with the likelihood that practitioners of CEUS would need to have attained at least a Level 2 of competency, if not higher. Currently, there are four agents licensed for use in Europe: Levovist (Schering, Berlin, Germany), Optison (GE Healthcare, Oslo, Norway), Definity (BristolMeyers Squibb, Uxbridge, UK) and SonoVue (Bracco, Milan, Italy).The sole indication to date for Optison and Luminity is for cardiac use. Practitioners in Japan have the advantage of access to another agent: Sonazoid (GE Healthcare, Oslo, Norway). Levovist, the oldest agent (having been introduced in 1996), is not sufficiently robust to be used adequately with the newer low mechanical index (MI) techniques. It does, however, have the characteristic of late phase ‘‘trapping’’ in the liver, a feature not demonstrated by some of the newer agents (except for Sonazoid) but which has been exploited to good effect in the past [3]. Current recommendations do not promote the use of high MI techniques to investigate liver lesions in the late phase, citing technical difficulties [1]. As a consequence, the most widely used agent currently for radiological indications in Europe is SonoVue This agent is particularly suited for the low MI techniques for the detection and characterization of focal liver lesions, with studies indicating that CEUS is as good, if not better, than contrast-enhanced CT [4, 5]. With CEUS, a ‘‘black hole’’ at the end of the portal venous phase almost always indicates a secondary malignant lesion (if a cyst has been excluded on the baseline examination) [1]. The usefulness of CEUS is not in doubt. Many new applications outside the traditional investigation of parenchymal liver lesions have developed or are evolving, with assessment of blunt abdominal trauma in the emergency room being particularly attractive [6]. The establishment of a standard CEUS ‘‘Bosniak’’ classification of renal cysts is also a possibility [7]. The list of useful applications grows as more investigators report their findings; however, the technique has not been fully embraced by the radiological community, despite the proven usefulness of CEUS. Uptake is slow, particularly in the UK, although ‘‘hot spots’’ exist. The European radiological community shows more interest in the use of CEUS, particularly in Italy. Japan and China are driving clinical practice with CEUS. However, there is a Address correspondence to: Paul S Sidhu, Department of Radiology, King’s College Hospital, Denmark Hill, London SE5 9RS, UK. E-mail: paul.sidhu@kch.nhs.uk The British Journal of Radiology, 81 (2008), 524–525