Applications of Ultrasound Microbubbles in the Spleen

Abstract

However, there is relatively few published data with regard to microbubbles and their behaviour in the spleen. The most widely used microbubble in Europe, Sono-Vue (Bracco, Italy), had always been thought to be a purely vascular contrast agent (Schneider et al. 1995;Correas et al. 2001;.We investigated the enhancement characteristics of SonoVue in the normal spleen in a cohort of ten healthy volunteers. Using a low acoustic power technique [Cadence Contrast Pulse Sequence (CPS), Sequoia, Acuson-Siemens, USA], the spleen was continuously scanned from 0 to 60 s and then again at 4 min. SonoVue (2.4 ml) was injected intravenously in all volunteers. Early analysis of this unpublished data revealed that in nine out of ten volunteers, there was heterogeneous, patchy enhancement of the spleen from 0 to 20 s (Fig. 14.1), with the spleen then becoming homogeneous throughout by 50 s (Fig. 14.2a). In one volunteer the spleen homogeneously enhanced even in the arterial phase. These enhancement characteristics are similar to those reported with iodinated contrast agents within the spleen on computed tomography (CT) and magnetic resonance (MR) imaging (Glazer et al. 1981;Mirowitz et al. 1991). These imaging characteristics are thought to be due to variable flow rates through the cords and sinuses of the red pulp (Groom 1987). Therefore it is recommended that lesion detection and assessment of the spleen with microbubbles should be in the late phase, at least 60 s post intravenous injection. The images at 4 min revealed that there was still a significant amount of contrast CONTENTS 14.1

Pseudoaneurysm in a chronic pancreatitis patient: report of a case, with emphasis on contrast-enhanced sonograms

“…However, its diagnostic sensitivity is more hindered by motion artifacts [14]. Recent advances in contrast-enhanced US have yielded increased image contrast in tissues, and this technique is expected to significantly improve the diagnostic confidence level in identifying non-perfused areas [15,16]. In our case, contrast-enhanced US performed 1 week after embolization therapy showed the aneurysm to be sufficiently embolized and the spleen to be free from infarction.…”

Splenic Hemangiomas

“…Actually, CT and MRI showed complete fill‐in in all 11 splenic hemangiomas in our study presenting on contrast‐enhanced sonography as hypoechoic masses in the late parenchymal phase (as shown in Figure 2). Some hypotheses can be made to explain this already reported atypical behavior 18 , 33 . First, as in the liver, splenic hemangiomas may contain large vascular channels and, consequently, internal slow flow.…”

Quantifying Activation of Perfluorocarbon-Based Phase-Change Contrast Agents Using Simultaneous Acoustic and Optical Observation

“…The routinely adopted diagnostic applications include using microbubbles as a blood pool marker for endocardial border delineation (Elhendy et al 2004; Kaufmann et al 2007) and liver vasculature imaging (Cosgrove 2007; Oldenburg et al 2005; Vilana et al 2006). Many other diagnostic applications also look promising, such as contrast-enhanced ultrasound imaging of the spleen (Harvey et al 2005) and kidney (Cosgrove and Chan 2008; Quaia et al 2003), as well as detection of neovascularization and atherosclerotic plaques (Coli et al 2008; Feinstein 2006) in the coronary and carotid arteries. Recent studies also promoted the use of microbubbles for quantitative (Sboros and Tang 2010; Tang et al 2011; Wei et al 1998), targeted and molecular imaging (Klibanov 2007).…”