Magnetic resonance parametric mapping of the spleen for non-invasive assessment of portal hypertension

Abstract

Objectives In patients with advanced liver disease, portal hypertension is an important risk factor, leading to complications such as esophageal variceal bleeding, ascites, and hepatic encephalopathy. This study aimed to determine the diagnostic value of T1 and T2 mapping and extracellular volume fraction (ECV) for the non-invasive assessment of portal hypertension. Methods In this prospective study, 50 participants (33 patients with indication for trans-jugular intrahepatic portosystemic shunt (TIPS) and 17 healthy volunteers) underwent MRI. The derivation and validation cohorts included 40 and 10 participants, respectively. T1 and T2 relaxation times and ECV of the liver and the spleen were assessed using quantitative mapping techniques. Direct hepatic venous pressure gradient (HVPG) and portal pressure measurements were performed during TIPS procedure. ROC analysis was performed to compare diagnostic performance. Results Splenic ECV correlated with portal pressure (r = 0.72; p < 0.001) and direct HVPG (r = 0.50; p = 0.003). No significant correlations were found between native splenic T1 and T2 relaxation times with portal pressure measurements (p > 0.05, respectively). In the derivation cohort, splenic ECV revealed a perfect diagnostic performance with an AUC of 1.000 for the identification of clinically significant portal hypertension (direct HVPG ≥ 10 mmHg) and outperformed other parameters: hepatic T2 (AUC, 0.731), splenic T2 (AUC, 0.736), and splenic native T1 (AUC, 0.806) (p < 0.05, respectively). The diagnostic performance of mapping parameters was comparable in the validation cohort. Conclusion Splenic ECV was associated with portal pressure measurements in patients with advanced liver disease. Future studies should explore the diagnostic value of parametric mapping accross a broader range of pressure values. Key Points • Non-invasive assessment and monitoring of portal hypertension is an area of unmet interest. • Splenic extracellular volume fraction is strongly associated with portal pressure in patients with end-stage liver disease. • Quantitative splenic and hepatic MRI-derived parameters have a potential to become a new non-invasive diagnostic parameter to assess and monitor portal pressure.

Diagnostic value of magnetic resonance parametric mapping for non-invasive assessment of liver fibrosis in patients with primary sclerosing cholangitis

“…Another promising MRI technique is relaxometry including ECV calculation. Significant correlations between hepatic T1, T2 as well as ECV with liver fibrosis have been already sufficiently described in the previous studies [ 17 , 20 , 21 , 37 – 39 ]. Liver fibrosis is defined as the accumulation of extracellular matrix proteins produced by fibrogenic cell populations in response to tissue injury.…”

“…Liver fibrosis is defined as the accumulation of extracellular matrix proteins produced by fibrogenic cell populations in response to tissue injury. As a consequence, this process leads to extension of extracellular space and increased accumulation of extracellular MRI contrast agent, which is reflected by prolonged T1 relaxation times and increased ECV of liver [ 21 ]. However, there is still no sufficient data proving correlations between MRE-derived liver stiffness and mapping parameters in patients with PSC.…”

Portal hypertension in cirrhosis: Pathophysiological mechanisms and therapy

“…Besides the MR-elastography, there are novel protocols measuring extracellular volume or Liver Inflammation and Fibrosis score, not requiring a specific device to measure portal pressure (141)(142)(143). This technique is mainly validated for fibrosis, but it also correlates with portal pressure as shown in animals (142)(143)(144). Still significant efforts are required to make it ready to the wide-use in the clinic, but it may be interesting as an one-stop-shop diagnostic approach.…”

Noninvasive assessment of clinically significant portal hypertension using ΔT1 of the liver and spleen and ECV of the spleen on routine Gd-EOB-DTPA liver MRI

“…Patients with chronic liver disease (CLD) and, in particular, cirrhosis have a high risk of developing clinically significant portal hypertension (CSPH) [1,2]. CSPH is associated with potentially fatal complications, such as variceal hemorrhage, ascites, hepatic encephalopathy, renal dysfunction, and adverse outcomes after liver surgery and transarterial chemoembolization [2][3][4][5][6]. Currently, liver cirrhosis is the fourth leading cause of death in the adult population of Central Europe and is responsible for approximately 170,000 deaths annually in Europe, and the majority of deaths are not due to hepatocyte failure but instead are due to complications associated with CSPH [7,8].…”

“…MRE allows a noninvasive quantitative measurement of the hepatic and splenic stiffness [16], which may represent a helpful biomarker for the characterization of patients with CSPH, as an increased splenic stiffness is associated with CSPH and gastroesophageal varices [17,18]. Recently, the T1 mapping-derived extracellular volume fraction (ECV) of the spleen has been shown to be able to distinguish between healthy volunteers and patients with severe portal hypertension undergoing a transjugular intrahepatic portosystemic shunt (TIPS) procedure [6]. This proof-of-concept study has demonstrated that MR T1 mapping techniques have good potential, not only when measured in the liver but also in the spleen.…”