Contrast‐Enhanced Ultrasound Guidance for Interventional Procedures

Abstract

Since its introduction, contrast-enhanced ultrasound (CEUS) has gained an important role in the diagnosis and management of abdominal and pelvic diseases. Contrast-enhanced ultrasound can improve lesion detection rates as well as success rates of interventional procedures when compared to conventional ultrasound alone. Additionally, CEUS enables the interventionalist to assess the dynamic enhancement of different tissues and lesions, without the adverse effects of contrast-enhanced computed tomography, such as exposure to ionizing radiation and nephrotoxicity from iodinated contrast material. This review article describes the various applications and advantages of the use of CEUS to enhance performance of ultrasound-guided interventions in the abdomen and pelvis.

Contrast enhancement for ultrasound-guided interventions: when to use it and what to expect?

“…The successful introduction of microbubble US contrast agents (UCAs) in the past decades has enabled a real-time contrast-enhanced assessment of various tumors, parenchyma, or complex pathological structures (7,8). Not only did the microbubbles enhance the diagnostic capacities of ultrasonography, but they also managed to enable interventional procedures performed either for diagnostic (aspiration, punctures, biopsies) or therapeutic (drainages, ablations) purposes (7,9,5,6,8,10).…”

“…The mechanisms, particularities, and advantages of various UCAs are well documented and are not the focus of the current review (5)(6)(7)11). However, the distinction between the two most frequently used contrast agents, SonoVue (Bracco Suisse, CH) and Sonazoid (GE Healthcare, Amersham, UK) is of A c c e p t e d A r t i c l e particular interest.…”

“…In contrast to SonoVue, Sonazoid is taken up by Kupffer cells in the post-vascular phase, leading to an additional postvascular phase, (Kupffer phase, 5 to 30 minutes after the injection), providing extremely stable images suitable for repeated scanning and interventions, and thus removing the time-constraint generated by a rapid contrast clearance. Moreover, the Sonazoid bubbles have a relatively narrow size distribution, are very robust, allowing for high mechanical index scanning (MI 0.2-0.3) and are not deterred by the use of higher US frequencies (5,12).…”

“…Conversely, to delineate the cavity of a collection (abscess, pseudocyst), only a few drops of UCA suffice to avoid artifact formation. The route of administration is either through a previously placed drainage tube or through a needle (18 G, Chiba), which is inserted into the cavity or excretory systems (biliary or renal) (5,9,11,(13)(14)(15). To address specific clinical questions (i.e., liver abscess) a combination of these two modalities, in any order, can be used.…”

“…Contrast-enhanced US (CEUS) has the capacity of emphasizing the macro and, above all, the microvascularization of parenchyma and tumors. Besides the well-accepted use in the detection and characterization of various tumors, the use of this technique has enabled the delimitation of areas with abnormal or absent vasculature (5,9,11,13). These unique features are valid for both focal A c c e p t e d A r t i c l e parenchymal lesions (tumors, abscesses) and post-procedural scars (i.e., postablation necrosis, embolization).…”