Contrast‐enhanced Ultrasonography in Normal Canine Liver. Evaluation of Imaging and Safety Parameters

Abstract

Contrast-enhanced ultrasonography, a new imaging modality in veterinary medicine, can provide data on tissue perfusion. The objective of this study was to use the ultrasonographic contrast agent SonoVue to evaluate various transit time indices in the normal canine liver, to examine the effect of anesthesia on these parameters, and to evaluate the safety of this agent in dogs. The liver of 11 healthy dogs was studied by ultrasound during an intravenous bolus injection of SonoVue. Each dog underwent the examination twice, first with and later without the use of anesthesia. A time-intensity curve was generated from a selected region of interest within the liver from each scanning session. Ratios derived from peak enhancement, time to peak enhancement, up-slope and full-width half-maximum (FWHM) of the curve were calculated from the time-intensity curves, and are reported. There were no statistically significant differences (P > 0.05) in peak enhancement, up-slope and FWHM between dogs that were anesthetized and dogs that were not. Time to peak enhancement, however, was significantly shorter when the dogs were anesthetized than when they were nonanesthetized (P < 0.05). There were no biologically significant changes in clinical laboratory findings. This study indicates that contrast-enhanced ultrasound using SonoVue gives reproducible liver perfusion data, and appears to be a safe and well-tolerated agent for use in dogs. When considering normal values, the use of anesthetic drugs has to be considered.

Vascular and Kupffer Imaging of Canine Liver and Spleen Using the New Contrast Agent Sonazoid

“…The previous report on CEU using SonoVue ® in canine liver demonstrates a different time course in which HP enhancement diminished within 3 min [3], whereas in the present study, HP enhancement continues for longer period (15 min). The discrepancy between these 2 results is attributed to the difference in contrast agents used.…”

Contrast-enhanced ultrasonography (CEUS) in canine liver examination

“…The liver is frequently the first organ in which neoplasm's metastasize from primary tumors in the abdominal cavity by blood vessels (Nyman et al 2005). The presence of a metastatic tumor with a diameter of 1.5 cm results in portal hypertension (blood vessel compression theory).…”

“…In comparison to contrast agents used in computer tomography or magnetic resonance imaging, UCAs remain in the intravascular space and do not diffuse outside blood vessels. Not all UCAs (Nyman et al 2005) allow the imaging of the third, delayed phase (parenchymal, Kuppfer). This probably depends (Stewart andSidhu 2006, Kanemoto et al 2008) on UCAs elimination by phagocytes, e.g.…”

“…The presence of a metastatic tumor with a diameter of 1.5 cm results in portal hypertension (blood vessel compression theory). To maintain a constant blood flow (Nyman et al 2005) (energy) the metastasis supplements its shortage from the hepatic artery or by arteiovenous shunts. The CEUS image (Nyman et al 2005) of metastatic tumors is various and is characterized by: a vascular ring, growing peripheral, necrotic center and various degree of calcification and density.…”

“…The first echo-enhancing substances were applied in cardiology and were incapable of penetrating the pulmonary bed. Ultrasound contrast media (Nyman et al 2005) are classified into two generations according to the gas present inside the microbubbles: I gen agents (Albumex, Levovist) contain air, while II gen agents contain perfluorocarbon or sulfur hexafluoride (SonoVue, Optison, Definity).…”