Imaging Assessment of Splenic Perfusion Using Contrast-Enhanced Ultrasound in Micropigs

Abstract

Contrast-enhanced ultrasound is one of the proper methods to analyze perfusion in the spleen. The aim of this project was to assess the perfusion pattern and dynamics in the normal micropigs spleen using contrast harmonic imaging. Clinically healthy twelve female micropigs (11~20 kg) 2~4 months were used in this study. All micropigs underwent a physical examination and basic blood analysis. Anesthesia of micropigs was induced with tiletamine and zolazepam and maintained with isoflurane. Time/mean pixel value (MPV) curves were generated for selected regions in the spleen. The splenic parenchyma was enhanced in 2 phases. First, the large splenic vessels enhanced rapidly and intensely, followed by a more gradual enhancement of the remainder of the parenchyma. For a bolus injection of contrast medium 0.05ml/kg, within the splenic parenchyma (averaging all subjects) the arrival time was 5.67 ± 1.15 (mean ± SD) sec, time to peak was 10.06 ± 1.60 sec, baseline intensity was 9.70 ± 2.70 MPV, peak intensity was 23.98 ± 5.38 MPV, wash in rate was 4.10 ± 1.60 MPV/s, and wash out rate was 0.78 ± 0.46 MPV/s. There is no significant difference between parameters at two doses of 0.05ml/kg and 0.07ml/kg (P > 0.05). The findings of these data can be used as normal reference values and may prove useful in the evaluation of micropigs with splenic disease.