Clinical evaluation of magnetic resonance imaging flowmetry of portal and hepatic veins in patients following hepatectomy

Abstract

Our results suggest that MRI flowmetry is a potentially useful tool for measurement of hepatic blood flow and recommend its use for estimation of liver cirrhosis-associated impairment.

Normal and Altered Three-dimensional Portal Venous Hemodynamics in Patients with Liver Cirrhosis

“…We therefore speculate that the differences in MR imaging and US flow measurements are mostly related to partial volume effects. Concordant with our findings, investigators in earlier studies report larger portal vein areas when assessed with MR imaging compared with Doppler US (15,35). A potential source of dissenting results between MR imaging and Doppler US measurements of portal vein area size may be measurement site differences, representing a limitation of our study.…”

“…In their study, Gaiani et al (45) described an overall prevalence of 4D MR imaging underestimations of 31%-39% compared with US measurements of blood-flow velocities in the carotid bifurcation. Nanashima et al (35) observed that underestimation of mean flow velocities in the portal vein by 19.2% occurred with MR imaging compared with Doppler US. The maximum (22.7 cm/sec 6 7.1) and mean (9.6 cm/ sec 6 3.1) velocities of MR imaging in our study were slightly lower than those in previous MR studies (ie, Yzet et al [16], with a maximum velocity of 28.2 cm/sec 6 8.8; Lycklama à Nijeholt et al [15] and Nanashima et al [35], with a mean velocity of 10.8 cm/sec 6 1.6 to 13.5 cm/sec 6 3.7).…”

“…Nanashima et al (35) observed that underestimation of mean flow velocities in the portal vein by 19.2% occurred with MR imaging compared with Doppler US. The maximum (22.7 cm/sec 6 7.1) and mean (9.6 cm/ sec 6 3.1) velocities of MR imaging in our study were slightly lower than those in previous MR studies (ie, Yzet et al [16], with a maximum velocity of 28.2 cm/sec 6 8.8; Lycklama à Nijeholt et al [15] and Nanashima et al [35], with a mean velocity of 10.8 cm/sec 6 1.6 to 13.5 cm/sec 6 3.7). With MR imaging, one may tend to underestimate velocity because velocity data are acquired over several cardiac cycles, which yields average velocity-time courses, but one cannot measure cycle-to-cycle velocity variations or short-term fluctuations.…”

“…In contrast to previous studies that were based on quantitative flow measurements (7,15,16,35), we evaluated not just portal venous hemodynamics but the flow in the extrahepatic vessels as well, including the superior mesenteric and splenic veins and intrahepatic vessels with the right and left intrahepatic portal vein branches. Almost all extrahepatic vessels were well visualized with good quality, with some limitations in the left intrahepatic branches.…”

The use of β-adrenergic drugs improves hepatic oxygen metabolism in cirrhotic patients undergoing liver resection

“…This procedure is associated with hemodynamic and oxygen metabolism disturbances of the residual liver that may lead to post-operative complications and liver failure [1][2][3]. In a normal liver, postoperative dysfunction may be transient and it is usually associated with intensive regeneration which depends on the supply of energy [4,5].…”