Heterogeneous delayed enhancement of hepatic parenchyma after intravenous infusion of sonographic contrast agent: a new hypothesis

Abstract

The phenomenon of heterogeneous hepatic enhancement may be related to gas from the intestinal microcirculation being transported to via the enteroportal circulation and becoming trapped in the hepatic sinusoids.

Delayed contrast enhancement of hepatic parenchyma after intravenous sonographic contrast agent: unusual phenomenon. Case report and review of literature

“…Free gas migration into the portal vessels may also be caused by intestinal ischemia, necrotic enterocolitis, or intestinal pneumatosis. Based on Caruso et al's research, the probable explanation could be gas embolization via enteroportal circulation caused by a rapid intravascular growth of the contrast microbubbles [8]. Based on our observation, immediate CT after CEUS confirmed no gas embolization in the enteroportal circulation.…”

“…At the present time, 21 delayed heterogeneous liver enhancement phenomenon cases using Levovist (Schering AG, Berlin, Germany; five cases), EchoGen (Sonus Pharmaceuticals, Bothell, WA, USA; one case), SonoVue (Bracco, Milan, Italy; eight cases), and perflubutane (Sonazoid; seven cases) microbubbles are known. The phenomenon with SonoVue became apparent 240 s after the injection (in the late phase) and increased over time [8,15,16,18]. HLHE also occurred with different contrast agents, even when different insonation techniques and ultrasound devices were used.…”

“…Other possible explanations based on findings from earlier animal and human experiments include sonographic contrast agents damaging the cell membranes and endothelium [8,[22][23][24][25]; microbubble fusion in vivo inside the sinusoids and mesenteric vessels [25]; and inflammation, necrosis, and ulceration of the cecum and proximal colon caused by sonographic contrast agents [26].…”

“…The behavior pattern of these chemically inert contrast agents is similar to that of the iodinated agents used for contrast phases. However, some biological interactions at the hematic level are still unknown [8]. The duration of a clinically useful enhancement using a bolus injection in the liver generally lasts 5-10 min.…”

“…Though enhancement and elimination patterns have been studied for these agents, only a few cases have been published about the delayed heterogeneous liver enhancement phenomenon when using different ultrasound (US) contrast media, e.g., Levovist (Schering AG, Berlin, Germany; five cases), EchoGen (Sonus Pharmaceuticals, Bothell, WA, USA; one case), SonoVue (Bracco, Milan, Italy; seven cases), and Sonazoid (GE Healthcare, Oslo, Norway; seven cases) [8,[15][16][17]. The mechanism of this phenomenon is still unknown [8].…”