title: Diminished liver microperfusion in Fontan patients: A biexponential DWI study.
abstract: It has been demonstrated that hepatic apparent diffusion coefficients (ADC) are decreasing in patients with a Fontan circulation. It remains however unclear whether this is a true decrease of molecular diffusion, or rather reflects decreased microperfusion due to decreased portal blood flow. The purpose of this study was therefore to differentiate diffusion and microperfusion using intravoxel incoherent motion (IVIM) modeled diffusion-weighted imaging (DWI) for different liver segments in patients with a Fontan circulation, compare to a control group, and relate with liver function, chronic hepatic congestion and hepatic disease. For that purpose, livers of 59 consecutively included patients with Fontan circulation (29 men; mean-age, 19.1 years) were examined (Oct 2012─Dec 2013) with 1.5T MRI and DWI (b = 0,50,100,250,500,750,1500,1750 s/mm2). IVIM (Dslow, Dfast, ffast) and ADC were calculated for eight liver segments, compared to a control group (19 volunteers; 10 men; mean-age, 32.9 years), and correlated to follow-up duration, clinical variables, and laboratory measurements associated with liver function. The results demonstrated that microperfusion was reduced (p<0.001) in Fontan livers compared to controls with ─38.1% for Dfast and ─32.6% for ffast. Molecular diffusion (Dslow) was similar between patients and controls, while ADC was significantly lower (─14.3%) in patients (p<0.001). ADC decreased significantly with follow-up duration after Fontan operation (r = ─0.657). Dslow showed significant inverse correlations (r = ─0.591) with follow-up duration whereas Dfast and ffast did not. From these results it was concluded that the decreasing ADC values in Fontan livers compared with controls reflect decreases in hepatic microperfusion rather than any change in molecular diffusion. However, with the time elapsed since the Fontan operation molecular diffusion and ADC decreased while microperfusion remained stable. This indicates that after Fontan operation initial blood flow effects on the liver are followed by intracellular changes preceding the formation of fibrosis and cirrhosis.
authors.affiliation: Center for Medical Imaging-North East Netherlands, Department of Radiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Hildebrand
authors.identifier: http://orcid.org/0000-0001-6664-902X
authors.initials: H
authors.lastname: Dijkstra
authors.affiliation: Center for Congenital Heart Diseases, Department of Pediatric Cardiology/Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Djoeke
authors.initials: D
authors.lastname: Wolff
authors.affiliation: Center for Congenital Heart Diseases, Department of Cardiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Joost P
authors.initials: JP
authors.lastname: van Melle
authors.affiliation: Center for Congenital Heart Diseases, Department of Pediatric Cardiology/Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Beatrijs
authors.initials: B
authors.lastname: Bartelds
authors.affiliation: Department of Radiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Tineke P
authors.initials: TP
authors.lastname: Willems
authors.affiliation: Center for Medical Imaging-North East Netherlands, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Matthijs
authors.initials: M
authors.lastname: Oudkerk
authors.affiliation: Department of Epidemiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Hans
authors.initials: H
authors.lastname: Hillege
authors.affiliation: Department of Gastroenterology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Aad P
authors.initials: AP
authors.lastname: van den Berg
authors.affiliation: Center for Congenital Heart Diseases, Department of Cardiothoracic Surgery University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Tjark
authors.initials: T
authors.lastname: Ebels
authors.affiliation: Center for Congenital Heart Diseases, Department of Pediatric Cardiology/Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Rolf M F
authors.initials: RM
authors.lastname: Berger
authors.affiliation: Department of Radiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Paul E
authors.initials: PE
authors.lastname: Sijens
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005234:Fatty Liver / Q000000981:diagnostic imaging / Q000503:physiopathology; D005260:Female; D018729:Fontan Procedure / Q000379:methods*; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008103:Liver Cirrhosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D018810:Magnetic Resonance Angiography / Q000379:methods; D008297:Male; D008962:Models, Theoretical; D010477:Perfusion