Using T1 mapping in cardiovascular magnetic resonance to assess congestive hepatopathy

Abstract

The goal of this study was to assess the ability of quantitative T1 cardiovascular magnetic resonance (CMR) imaging to calculate liver extracellular volume (ECV) in patients with varying degrees of congestive hepatopathy (CH). T1 measurements and ECV calculations were performed retrospectively in three cohorts of patients: normal cardiac function, tetralogy of fallot (TOF) repair and Fontan palliation. All CMR studies included modified look-locker inversion recovery (MOLLI) T1 mapping scans performed pre- and post-injection of a gadolinium-based contrast agent (GBCA). Pixel intensity data were manually collected from images of the liver and cardiac blood pool to determine contrast-induced changes in T1 for liver and blood. These data were then used to compute liver ECV. 172 subjects were included in the study. Of these, 140 subjects were normal cardiac function patients, 16 were TOF repair patients and 16 patients were with Fontan palliation. A statistically significant difference in both the liver native T1 and ECV measurements was found between patients with normal cardiac function vs. Fontan palliation patients (p < 0.01). Our data indicate that measuring T1 maps both pre- and post-GBCA injection within CMR scan session can be used to follow progression of liver fibrosis. This technique has the potential to improve diagnosis and treatment of patients with chronic liver disease and liver fibrosis.

Increased extracellular volume in the liver of pediatric Fontan patients

“…Only pilot data in 16 adult Fontan patients yielded CMR T1 and ECV levels comparable to our cohort [14]. In our study, Fontan patients demonstrated elevated native T1 times, in line with results from USE, computed tomography and postmortem studies which have indicated increased stiffness and evidence of fibrosis [31–34].…”

“…All ROIs were traced to avoid major vessels, the gall bladder and hepatic surface (Fig. 1) [13, 14]. For blood pool T1 measurements, ROIs were placed in the cardiac lumen and in a hepatic vein as close as possible to the diaphragm, while avoiding myocardial trabeculations and hepatic tissue, respectively.…”

Hepatic magnetic resonance T1-mapping and extracellular volume fraction compared to shear-wave elastography in pediatric Fontan-associated liver disease

“…The elevated hepatic T1, extracellular volume fraction, and elastography values confirmed previous findings from retrospective MR studies in adults and children with Fontan [18,21,22] and studies on US and MR elastography after Fontan completion [19,20,27,28]. The advantage of our study was the representative, unselected, relatively large national cohort of adolescents with Fontan circulation.…”

“…US shear-wave elastography is simpler and less resource-demanding than MR, and is routinely used to assess adult chronic liver disease [16,17]. Few studies have employed hepatic MR T1 mapping or elastography to evaluate fibrosis or congestion in people with Fontan circulation [18][19][20][21][22]. We hypothesized that adolescents with Fontan circulation might display elevations in fibrosis markers, based on MR T1 mapping, extracellular volume fraction, and US shear-wave elastography.…”

Simultaneous proton density fat‐fraction and imaging with water‐specific T1 mapping (PROFIT1): application in liver

“…Commonly used and widely available myocardial T 1 -mapping methods based on balanced steady-state free-precession (bSSFP) acquisitions, such as modified Look-Locker inversion recovery (MOLLI) 12 or shortened MOLLI (ShMOLLI), 13 are increasingly used for T 1 mapping in the liver. 2,[14][15][16][17] Unfortunately, these methods have large and complex T 1 errors when applied to mixed water-fat systems. 16,18 A fat-correction approach for the ShMOLLI T 1 mapping method has been illustrated, but requires additional acquisitions to assess off-resonance frequency and fat content, in combination with numerical simulations.…”