title: Acute outflow obstruction of hepatic veins in rabbits: quantitative analysis of hepatic perfusion with contrast-enhanced sonography.
abstract: OBJECTIVE
  To compare time-enhancement curve parameters of contrast-enhanced sonography in acute partial hepatic venous outflow obstruction with those of a baseline study.
  
  
  METHODS
  Contrast-enhanced sonography was performed in 11 rabbits with bolus administration of a sulfur hexafluoride contrast agent (0.1 mL/kg). After baseline scanning for 3 minutes, a 5.3F balloon catheter was placed into the left hepatic vein. Obstruction was artificially induced by 0.4-mL balloon inflation, and sonography was repeatedly performed thereafter. On images stored with 1-second intervals, 2 × 2-mm regions of interest were placed, and mean luminosity was measured. Time-enhancement curves were plotted, and contrast arrival times, peak enhancement values, peak enhancement times, 50% wash-out times, and 3-minute wash-out rates were obtained. Paired t tests were performed to evaluate the significance of differences in the parameters between baseline and obstruction.
  
  
  RESULTS
  On baseline sonography, the median contrast arrival time, peak enhancement value, peak enhancement time, 50% wash-out time, and 3-minute wash-out rate were 6 (range, 4-8; mean ± SD, 5.9 ± 1.2) seconds, 188.5 (104.7-209.5; 178.4 ± 33.1) arbitrary units, 19 (14-27; 19.8 ± 4.1) seconds, 75 (60-101; 78.2 ± 13.9) seconds, and 89.7% (81.3%-95.1%; 88.4% ± 4.9%), respectively. With obstruction, those values were 7 (5-12; 6.9 ± 2.3) seconds, 202.8 (98.2-215.1; 186.0 ± 39.3) arbitrary units, 31 (17-59; 32 ± 11.6) seconds, 101 (47-136; 96.2 ± 23.6) seconds, and 79.2% (66.2%-88.8%; 79.1% ± 7.6%). Compared with baseline, the peak enhancement time was significantly delayed from 19 to 31 seconds (P = .0027), 50% wash-out time significantly delayed from 75 to 101 seconds (P = .0209), and 3-minute wash-out rate significantly decreased from 89.7% to 79.2% (P < .0001) with obstruction, but there were no significant differences in contrast arrival times and peak enhancement values (P = .0756 and .2179).
  
  
  CONCLUSIONS
  Contrast-enhanced sonography can provide quantitative assessment of microbubble congestion in partial hepatic venous outflow obstruction. The peak enhancement time and 50% wash-out time are delayed and 3-minute wash-out rate is decreased in rabbits with artificially induced obstruction compared with a baseline study.
authors.affiliation: Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Pungnap-2 Dong, Songpa-ku, Seoul 138-736, Korea.
authors.forename: Kyoung Won
authors.initials: KW
authors.lastname: Kim
authors.forename: Pyo Nyun
authors.initials: PN
authors.lastname: Kim
authors.forename: Ji Hoon
authors.initials: JH
authors.lastname: Shin
authors.forename: Dong Ho
authors.initials: DH
authors.lastname: Shin
authors.forename: Woo Kyoung
authors.initials: WK
authors.lastname: Jeong
authors.forename: Hyung Jin
authors.initials: HJ
authors.lastname: Won
authors.forename: Yong Moon
authors.initials: YM
authors.lastname: Shin
authors.forename: Won Jae
authors.initials: WJ
authors.lastname: Lee
authors.forename: Moon Gyu
authors.initials: MG
authors.lastname: Lee
authors.forename: Gi-Won
authors.initials: GW
authors.lastname: Song
authors.forename: Shin
authors.initials: S
authors.lastname: Hwang
authors.forename: Sung-Gyu
authors.initials: SG
authors.lastname: Lee
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity; D003287:Contrast Media; D006503:Hepatic Veins / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D006504:Hepatic Veno-Occlusive Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D008102:Liver Circulation; D008297:Male; D055420:Perfusion Imaging / Q000379:methods*; D010743:Phospholipids; D011817:Rabbits; D013459:Sulfur Hexafluoride; D014463:Ultrasonography / Q000379:methods*
chemical_list: D003287:Contrast Media; D010743:Phospholipids; C420843:contrast agent BR1; D013459:Sulfur Hexafluoride