Ipek-Ugay Selcan, Tzschätzsch Heiko, Braun Jürgen, Fischer Thomas, Sack Ingolf
Department of Radiology, Charité-Universitätsmedizin Berlin, Berlin, Germany.
Department of Institute of Medical Informatics, Charité-Universitätsmedizin Berlin, Berlin, Germany.
J Ultrasound Med. 2017 Jul;36(7):1305-1311. doi: 10.7863/ultra.16.07046. Epub 2017 Mar 20.
Liver stiffness increases after intake of food or water, suggesting that hepatic venous blood flow affects the results of elastographic measurements. This study investigated the correlation between in vivo liver stiffness and hepatic blood flow using the Valsalva maneuver for reducing intrahepatic venous blood flow.
Intrahepatic changes in venous blood flow were assessed by sonography based on the pulsed wave Doppler velocity, vessel diameter assessment, and blood flow volume measurements in the portal vein and right hepatic vein. Time-harmonic elastography at 7 harmonic driving frequencies (30-60 Hz) was used to measure liver stiffness in the right liver lobe of 15 healthy volunteers.
The right hepatic vein diameter, flow volume, and peak pulsed wave velocity decreased during the Valsalva maneuver from mean ± SD values of 8.64 ± 1.85 to 6.55 ± 1.84 mm (P = .002), 0.53 ± 0.23 to 0.37 ± 0.26 L/min (P = .037), and 22.14 ± 4.87 to 17.38 ± 5.41 cm/s (P = .01), respectively. This maneuver decreased liver stiffness in all volunteers by a mean of approximately 13% from 1.71 ± 0.22 to 1.48 ± 0.22 m/s (P = .00006).
Our results demonstrate that liver stiffness is sensitive to altered venous blood flow, which is of clinical importance when using elastography for evaluation of portal hypertension. Furthermore, our results indicate that accurate measurement of liver stiffness requires standardized breathing conditions to rule out effects of changes in hepatic blood flow on elastographic findings.
摄入食物或水后肝脏硬度会增加，这表明肝静脉血流会影响弹性成像测量结果。本研究利用瓦尔萨尔瓦动作减少肝内静脉血流，调查了体内肝脏硬度与肝血流之间的相关性。
通过超声检查基于脉冲波多普勒速度、血管直径评估以及门静脉和右肝静脉的血流量测量来评估肝内静脉血流变化。使用7种谐波驱动频率（30 - 60Hz）的时间谐波弹性成像来测量15名健康志愿者右肝叶的肝脏硬度。
在瓦尔萨尔瓦动作期间，右肝静脉直径、血流量和脉冲波峰值速度从平均±标准差的值8.64±1.85毫米降至6.55±1.84毫米（P = 0.002），从0.53±0.23升/分钟降至0.37±0.26升/分钟（P = 0.037），从22.14±4.87厘米/秒降至17.38±5.41厘米/秒（P = 0.01）。此动作使所有志愿者的肝脏硬度平均降低约13%，从1.71±0.22米/秒降至1.48±0.22米/秒（P = 0.00006）。
我们的结果表明肝脏硬度对静脉血流改变敏感，这在使用弹性成像评估门静脉高压时具有临床重要性。此外，我们的结果表明准确测量肝脏硬度需要标准化的呼吸条件，以排除肝血流变化对弹性成像结果的影响。
