Experimental study on phase timing of rabbit liver VX2 tumor by contrast-enhanced ultrasonography : comparison with multidetector spiral CT

Abstract

Objective To investigate the imaging characteristics of rabbit liver VX2 tumor with contrast-enhanced ultrasonography(CEUS) and multidetector spiral CT(MDCT), to explore the criterion of phase timing apllicable to the model.Methods CEUS and MDCT were acquired in thirty-three New Zealand rabbits with hepatic VX2 tumors.The initial time of hepatic arterial phase was verified as the time the hepatic artery beginning to enhance,the initial time of portal phase as the time the VX2 tumor reaching peak enhancement and the initial time of hepatic parenchymal phase as the time the hepatic parenchyma reaching peak enhancement.The enhancing characteristics were observed.The time-intensity curve of VX2 tumor and peripheral parenchyma in CEUS was analysed and compared with the time-desity curve of abdominal aorta, portal vein, hepatic parenchyma and tumor in MDCT.Results The initial time of heptic arterial phase,portal phase and parenchymal phase in CEUS and MDCT was (6.82±1.36)s and (9.43±2.23)s,(11.64±2.03)s and (13.77±2.01)s,(20.24±4.17)s and (22.71± 4.58)s,respectively.The initial time of each phase in CEUS was earlier than that in MDCT (P<0.01).The contrast enhancing characteristics in CEUS and MDCT were consistent as fast wash-in and fast wash-out.Conclusions The status of hemodynamic perfusion in rabbit hepatic VX2 tumor could be well displayed by CEUS and the phase timing criterion concluded in this experimental study could offer fundmental theory basis for relevant imaging evaluation. Key words: Ultrasonography; Microbubbles; Tomography, Spiral Computed; Liver rabbits; Liver neoplasms, experimental