title: Quantification of hepatic blood flow using a high-resolution phase-contrast MRI sequence with compressed sensing acceleration.
abstract: OBJECTIVE. The objective of our study was to evaluate the performance of a high-spatial-resolution 2D phase-contrast (PC) MRI technique accelerated with compressed sensing for portal vein (PV) and hepatic artery (HA) flow quantification in comparison with a standard PC MRI sequence. SUBJECTS AND METHODS. In this prospective study, two PC MRI sequences were compared, one with parallel imaging acceleration and low spatial resolution (generalized autocalibrating partial parallel acquisition [GRAPPA]) and one with compressed sensing acceleration and high spatial resolution (sparse). Seventy-six patients were assessed, including 37 patients with cirrhosis. Two observers evaluated PC image quality. Quantitative analyses yielded a mean velocity, flow, and vessel area for the PV and HA and an arterial fraction. The PC techniques were compared using the paired Wilcoxon test and Bland-Altman statistics. The sensitivity of the flow parameters to the severity of cirrhosis was also assessed. RESULTS. Vessel delineation was significantly improved using the PC sparse sequence (p < 0.034). For both in vitro and in vivo measurements, PC sparse yielded lower estimates for vessel area and flow, and larger differences between PC GRAPPA and PC sparse were observed in the HA. PV velocity and flow were significantly lower in patients with cirrhosis on both PC sparse (p < 0.001 and p = 0.042, respectively) and PC GRAPPA (p < 0.001 and p = 0.005, respectively). PV velocity correlated negatively with Child-Pugh class (r = -0.50, p < 0.001), whereas the arterial fraction measured with PC sparse was higher in patients with Child-Pugh class B or C disease than in those with Child-Pugh class A disease, with a trend toward significance (p = 0.055). CONCLUSION. A high-spatial-resolution highly accelerated compressed sensing technique (PC sparse) allows total hepatic blood flow measurements obtained in 1 breath-hold, provides improved delineation of the hepatic vessels compared with a standard PC MRI sequence (GRAPPA), and can potentially be used for the noninvasive assessment of liver cirrhosis.
authors.affiliation: 1 Department of Radiology, Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Pl, New York, NY 10029.
authors.forename: Hadrien A
authors.initials: HA
authors.lastname: Dyvorne
authors.forename: Ashley
authors.initials: A
authors.lastname: Knight-Greenfield
authors.forename: Cecilia
authors.initials: C
authors.lastname: Besa
authors.forename: Nancy
authors.initials: N
authors.lastname: Cooper
authors.forename: Julio
authors.initials: J
authors.lastname: Garcia-Flores
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Schiano
authors.forename: Michael
authors.initials: M
authors.lastname: Markl
authors.forename: Bachir
authors.initials: B
authors.lastname: Taouli
mesh_terms: D005260:Female; D006499:Hepatic Artery / Q000502:physiology*; D006801:Humans; D008103:Liver Cirrhosis / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011169:Portal Vein / Q000502:physiology*; D011446:Prospective Studies; D012039:Regional Blood Flow
keywords: cirrhosis; hepatic artery flow; phase-contrast MRI; portal hypertension; portal vein flow