Noninvasive prediction of portal pressure with MR elastography and DCE-MRI of the liver and spleen: Preliminary results

Abstract

Background: Portal hypertension (PH), defined by hepatic venous pressure gradient (HVPG) ≥5 mmHg and clinically significant PH, defined by HVPG ≥10 mmHg, are complications of chronic liver disease.

Purpose: To assess the diagnostic performance of MR elastography (MRE) and dynamic contrast-enhanced MRI (DCE-MRI) of the liver and spleen for the prediction of PH and clinically significant PH, in comparison with a qualitative PH imaging scoring system.

Study type: IRB-approved prospective study.

Population: In all, 34 patients with chronic liver disease who underwent HVPG measurement.

Field strength/sequence: 1.5/3T examination including 2D-GRE MRE (n = 33) and DCE-MRI of the liver/spleen (n = 28).

Assessment: Liver and spleen stiffness were calculated from elastogram maps. DCE-MRI was analyzed using model-free parameters and pharmacokinetic modeling. Two observers calculated qualitative PH imaging scores based on routine images.

Statistical tests: Imaging parameters were correlated with HVPG. Receiver operating characteristic (ROC) analysis was performed for prediction of PH and clinically significant PH.

Results: There were significant correlations between DCE-MRI parameters (liver time-to-peak, r = 0.517 / P = 0.006, liver distribution volume, r = 0.494 / P = 0.009, liver upslope, r = -0.567 / P = 0.002), liver stiffness (r = 0.478 / P = 0.016), PH imaging score (r = 0.441 / P = 0.009), and HVPG. ROC analysis provided significant area under the ROC (AUROCs) for PH (liver upslope 0.765, liver stiffness 0.809, spleen volume/diameter 0.746-0.731, PH imaging score 0.756) and for clinically significant PH (liver and spleen perfusion parameters 0.733-0.776, liver stiffness 0.742, PH imaging score 0.742). The ratio of liver stiffness to liver upslope had the highest AUROC for diagnosing PH (0.903) and clinically significant PH (0.785).

Data conclusion: These preliminary results suggest that the combination of liver stiffness and perfusion metrics provide excellent accuracy for diagnosing PH, and fair accuracy for clinically significant PH. Combined MRE and DCE-MRI outperformed qualitative imaging scores for prediction of PH.

Level of evidence: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;48:1091-1103.

Keywords: dynamic-contrast enhanced MRI; magnetic resonance elastography; magnetic resonance imaging; portal hypertension.

© 2018 International Society for Magnetic Resonance in Medicine.

Figures

Figure 1

Correlation plots displaying significant correlations between imaging parameters and HVPG measurements (DV: distribution volume, HVPG: hepatic venous pressure gradient; LS: liver stiffness; LSLU: ratio of liver stiffness and liver upslope; MRE: magnetic resonance elastography; PH: portal hypertension, TTP: time to peak).

Figure 2

Top: 59 year-old female patient with chronic hepatitis C and moderate liver fibrosis (METAVIR F2) without portal hypertension (HVPG=3 mm). Bottom: 46 year-old female patient with alcoholic cirrhosis (METAVIR F4) and clinically significant portal hypertension (HVPG=18 mm). Patient with clinically significant portal hypertension had higher liver and spleen stiffness (12 and 14.3 kPa vs. 2.2 and 5.1 kPa, respectively), and increased liver and spleen TTP (time-to-peak) (liver in blue: 69.0 s and spleen in red: 13.6 s vs. 29.5 s and 10.9 s, respectively), with decreased liver upslope (0.007 vs. 0.015 mmol/L.s). LSLU (ratio of liver stiffness and liver upslope) was higher in patient with clinically significant portal hypertension than in patient without PH (1664 vs. 152).

Figure 3

53 year-old female patient with chronic hepatitis B cirrhosis (METAVIR F4) and clinically significant portal hypertension (HVPG = 27 mmHg). A: Liver stiffness map obtained with MRE. Liver stiffness value was 4.99 kPa, below cutoff value of 5.75 kPa for clinically significant portal hypertension (false negative), while the portal hypertension imaging score correctly diagnosed clinically significant portal hypertension (score of 6 for both readers). Of note, spleen stiffness was not measured in this case. B and C: Axial T1-weighted post-contrast images demonstrate variceal sites (white arrows), D: Coronal T2-weighted image demonstrates moderate ascites and splenomegaly.