Magnetic Resonance Elastography of the Liver in Patients Status-Post Fontan Procedure: Feasibility and Preliminary Results

Abstract

Objective: The purpose of this study was to evaluate the feasibility of performing MR Elastography (MRE) as a screening tool for elevated liver stiffness in patients’ status-post Fontan procedure. With Fontan patients now reaching adulthood, one of the factors that is increasingly affecting long-term prognosis is the presence of hepatic congestion and fibrosis. When the liver fibrosis progresses to cirrhosis, these patients may be candidates for liver transplantation. However, if detected early, steps can be taken to potentially slow or halt the progression of hepatic fibrosis. Currently, liver biopsy is the gold-standard for assessing liver fibrosis. Magnetic Resonance Elastography (MRE) is a relatively new, non-invasive imaging technique that quantitatively measures liver stiffness and provides an estimate of fibrosis extent. A retrospective study was performed evaluating liver stiffness with MRE in patients with a history of Fontan procedure. The MRE of the liver was performed in the same session as a clinical cardiac MRI. Liver stiffness values were calculated by drawing regions-of-interest on the stiffness maps. The mean liver stiffness and its correlation with the length of time since Fontan surgery were studied. Sixteen patients with 17 MRE exams were included in this study. All patients had elevated liver stiffness values by MRE, suggesting the presence of mild to severe fibrosis, and there was a trend towards higher liver stiffness with greater duration of time with the Fontan circulation. MRE is a feasible method for evaluating the liver in patients status-post Fontan procedure who are undergoing surveillance cardiac MRI. Our preliminary study shows that duration of hepatic congestion following Fontan procedure may be related to liver stiffness. Further investigation with histologic correlation is needed to determine the etiology and long-term sequela of elevated liver stiffness in this population.

Liver Nodules after the Fontan Operation: Role of Magnetic Resonance Elastography

“…As a supplement to these findings of Serai and colleagues, 5 our own results show that MRE-derived liver stiffness can corroborate cardiac catheterization-derived pressure measurements and biopsy results. Magnetic resonance elastography can prove itself useful in establishing correlates of detection and staging of liver fibrosis in patients who have undergone the Fontan operation.…”

“…The results of a recent pilot study exemplified the feasibility of using MRE to screen post-Fontan patients: among 17 patients, the median liver stiffness was 5.1 kPa, which indicated severe fibrosis. 5 However, liver biopsy specimens and cardiac catheterization data were not analyzed; therefore, the relationships of histopathology and hemodynamics to liver stiffness were unknown.…”

Retrospective comparison of gradient recalled echo R2* and spin-echo R2 magnetic resonance analysis methods for estimating liver iron content in children and adolescents

“…These limitations of liver biopsy highlight the need for a noninvasive test that can accurately and objectively measure the degree of hepatic hemosiderosis, especially in children, for whom the risk-to-benefit ratio of biopsy must be even more carefully weighed than in adults [2,16]. Thus noninvasive diagnostic methods are highly attractive [2,[15][16][17][18][19]. Recently, noninvasive methods to determine LIC by MRI have gained popularity [2,16,[18][19][20][21][22][23].…”

“…Thus noninvasive diagnostic methods are highly attractive [2,[15][16][17][18][19]. Recently, noninvasive methods to determine LIC by MRI have gained popularity [2,16,[18][19][20][21][22][23]. These methods have been validated to biopsy by at least three groups of investigators and are being used clinically by many centers, including ours [20,22,23].…”

Management of the Fontan circulation in the adult patient

“…(143)(144)(145) Screening for hepatic adenomas by annual liver imaging and alpha-feto protein levels has been recommended and is a low cost way of identifying these cases early in their disease course. (146)(147)(148) …”