Gray scale contrast enhancement and quantification in different positions of rabbit liver.

Objective: The purpose of this study was to evaluate the difference between central and ventral peripheral positions and the difference between left and right lobes in rabbit liver with gray scale contrast enhancement.

Methods: An in vivo model of perfusion was studied with a sulfur hexafluoride contrast agent and low-mechanical-index, real-time, gray scale harmonic imaging. The contrast agent (0.1 mL/kg body weight) was applied respectively in 10 rabbits by intravenous bolus injection. The time-intensity curve was used to obtain flow-related parameters such as time to enhancement (ET), time to peak intensity (PIT), peak signal intensity (PSI), enhancement duration (ED), and area under the curve (AUC).

Results: There was a significant difference in parameters of the time-intensity curve between central and peripheral ventral positions of liver parenchyma (P < .05), except for the ED in the left liver. The ET and PIT were earlier, the PSI higher, the ED longer, and the AUC larger in the central position of parenchyma than in the peripheral position. In addition, the ET and PIT were earlier, the PSI higher, the ED longer, and the AUC larger in the right lobe of liver parenchyma than in the left lobe. There was a significant difference in parameters of the time-intensity curve between the left and right lobes of liver parenchyma (P < .05), except for the ET of the peripheral position.

Conclusions: Flow parameters are different between central and ventral peripheral positions and between left and right lobes of hepatic parenchyma.