title: Four-dimensional velocity mapping of the hepatic and splanchnic vasculature with radial sampling at 3 tesla: a feasibility study in portal hypertension.
abstract: OBJECTIVE
  To demonstrate the feasibility of PC-VIPR (Phase Contrast Vastly undersampled Imaging with Projection Reconstruction) for the depiction and hemodynamic analysis of hepatic and splanchnic vessels in patients with portal hypertension.
  
  
  METHODS
  Twenty-four cirrhotic patients (55.9 ± 10.4 years) were scanned using 5-point PC-VIPR for high spatial resolution imaging with large volume coverage at 3 Tesla (T) using a 32-channel body coil. Vessel segmentation and hemodynamic visualization included color-coded three-dimensional (3D) streamlines and particle traces. Segmentation quality was compared with contrast-enhanced multi-phase liver imaging. Flow pattern analysis was performed in consensus of three readers. The MELD score was calculated to estimate disease severity and was correlated to image quality.
  
  
  RESULTS
  Good to excellent visualization quality was achieved in 23/24 cases. All arterial vessels and 144/168 vessels of the portal venous (PV) circulation were unambiguously identified. No correlation with the MELD score was found. Eight of 148 vessels of the PV circulation demonstrated reverse (hepatofugal) flow. Hepatofugal flow in small tributaries to PV flow were present in three cases despite hepatopetal flow in the PV.
  
  
  CONCLUSIONS
  This feasibility study demonstrates the feasibility of PC-VIPR for simultaneous morphological and hemodynamic assessment of the hepatic and splanchnic vasculature in cirrhosis and portal hypertension. Future studies with quantitative analyses are warranted.
authors.affiliation: Department of Radiology, University of Wisconsin-Madison, Wisconsin 53729, USA. frydrychowic@wisc.edu
authors.forename: A
authors.initials: A
authors.lastname: Frydrychowicz
authors.forename: B R
authors.initials: BR
authors.lastname: Landgraf
authors.forename: E
authors.initials: E
authors.lastname: Niespodzany
authors.forename: R W
authors.initials: RW
authors.lastname: Verma
authors.forename: A
authors.initials: A
authors.lastname: Roldán-Alzate
authors.forename: K M
authors.initials: KM
authors.lastname: Johnson
authors.forename: O
authors.initials: O
authors.lastname: Wieben
authors.forename: S B
authors.initials: SB
authors.lastname: Reeder
mesh_terms: D001783:Blood Flow Velocity; D005240:Feasibility Studies; D005260:Female; D006499:Hepatic Artery / Q000473:pathology* / Q000503:physiopathology*; D006801:Humans; D006975:Hypertension, Portal / Q000473:pathology* / Q000503:physiopathology*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013152:Splanchnic Circulation