Time-intensity-based quantification of vascularity with single-level dynamic contrast-enhanced ultrasonography: a pilot animal study.
OBJECTIVE
The purpose of this study was to delineate the hemodynamic features of VX2 tumor and perineoplastic liver parenchyma and to evaluate the potential usefulness of single-level dynamic ultrasonography in the diagnosis of tumors by the analysis of time-intensity curves.


METHODS
An in vivo animal model was studied using a low mechanical index in conjunction with single-level dynamic contrast-enhanced ultrasonography. A sulfur hexafluoride contrast agent (SonoVue; Bracco SpA, Milan, Italy) was applied in 8 rabbits by intravenous bolus injection. Data were acquired before and after VX2 tumor induction. Corresponding parameters of the time-intensity curve were measured using wash-in/wash-out curve software.


RESULTS
No significant difference was found in the time to enhancement, time to peak intensity, peak signal intensity, and enhancement duration between liver parenchyma before and after VX2 tumor induction (P > .05). The typical enhancement pattern of VX2 tumors was hyperechoic relative to liver parenchyma during the early phase and hypoechoic during the later phase. The curves obtained in carcinomas revealed an early arrival time and time to peak intensity with an irregular and sharp decrease of the intensity signal and a very early return to baseline, presenting a much more rapid wash-in and wash-out of ultrasonographic contrast agents. There was a significant difference in the time to enhancement, time to peak intensity, peak signal intensity, and enhancement duration between the VX2 tumors and perineoplastic liver parenchyma (P < .001).


CONCLUSIONS
Single-level dynamic contrast-enhanced ultrasonography with a low mechanical index level could provide real-time and continuous enhanced images and fully delineate the typical enhancement pattern of liver tumors. The analysis of time-intensity curves may provide useful, complementary, and quantitative information. This technique may be useful for the diagnosis of liver tumors, especially those showing an atypical enhancement pattern on biphasic helical computed tomographic scanning.
Li
Jie
J
Department of Ultrasound, Qilu Hospital, Shandong University, School of Medicine, Jinan 250012, China. jieli301@hotmail.com
Dong
Bao-wei
BW
Yu
Xiao-ling
XL
Wang
Xing-hua
XH
Li
Chuan-fu
CF
D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage* / Q000493:pharmacokinetics; D004195:Disease Models, Animal; D006439:Hemodynamics / Q000502:physiology; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008099:Liver / Q000000981:diagnostic imaging*; D008113:Liver Neoplasms / Q000098:blood supply* / Q000175:diagnosis* / Q000000981:diagnostic imaging; D008297:Male; D010743:Phospholipids / Q000493:pharmacokinetics; D010865:Pilot Projects; D011817:Rabbits; D013459:Sulfur Hexafluoride / Q000493:pharmacokinetics; D013997:Time Factors; D014463:Ultrasonography
D003287:Contrast Media; D010743:Phospholipids; C420843:contrast agent BR1; D013459:Sulfur Hexafluoride