Abstract:

Objective: To compare the efficacy of the non-contrast-enhanced magnetic resonance angiography (NC-MRA) with flow inversion recovery (FIR) sequence and contrast enhancement MRA(CE-MRA) on portal vein imaging in the cirrhotic portal hypertension. Methods: Twenty patients diagnosed as the cirrhotic portal hypertension by the clinical criteria or radiology were enrolled, and CE-MRA with fast field echo 3D coronal imaging and NC-MRA with FIR were performed to display the portal vein system, respectively. The imaging quality of the portal vein, splenic vein and superior mesenteric vein in the portal vein system on NC-MRA was compared with CE-MRA, and the signal-to-noise ratios of images the were calculated. Results: The width of the main portal vein and splenic vein measured by NC-MRA was not different from CE-MRA(P value was 0.330 and 0.090, respectively), and the scores of the imaging quality in splenic vein and proximal superior mesenteric vein had no difference either(P=0.677, P=0.077）. The imaging quality showed the clarity and the smooth degree in the portal vein and the branches of grade 1-2 on NC-MRA was superior to CE-MRA. However, the cases with image quality score ≥3 detected by NC-MRA were less than CE-MRA (9 vs 17, P=0.008), indicating CE-MRA had advantage in displaying distal veins over NC-MRA. The signal intensity and signal-to-noise ratios on NC-MRA were higher than CE-MRA(P=0.040, P<0.01). Conclusions: The NC-MRA with FIR sequence could clearly display the main blood vessels of the portal vein system in patients with the portal hypertension and shows similar efficacy as CE-MRA. NC-MRA with FIR sequence could be used as a safe and invasive method for displaying the portal vein system in spite of the lower efficacy on displaying distal veins.

Key words: Liver cirrhosis, Portal hypertension, Non-contrast-enhanced magnetic resonance