Imaging features of porto-sinusoidal vascular disorder in a case-control study: diagnostic value for differentiation...

Porto-sinusoidal vascular disorder (PSVD) is often misdiagnosed as liver cirrhosis due to overlapping clinical presentations and imaging features. This study conducted a blinded, independent imaging review to identify and compare the distinct imaging features between the two diseases, and to develop and validate a predictive model for differentiating PSVD from cirrhosis.

Patients with histologically and clinically confirmed PSVD or cirrhosis and available contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI) scans were retrospectively enrolled in the study. Imaging features were independently and systematically analyzed by two abdominal radiologists, who were blinded to the case grouping. Inter-reader discrepancies were resolved by consensus. The key features for analysis included liver surface nodularity (LSN), regenerative nodules (RNs), signs of portal hypertension (PH), and reticular delayed enhancement of the hepatic parenchyma. CT, MRI, and combined predictive models were developed to identify the top performing model, which was then selected and validated on an independent test cohort. Model performance was evaluated based on the area under the curve (AUC), sensitivity, and specificity.

In total, 106 patients with PSVD and 104 patients with cirrhosis were included for imaging evaluation and model development. The data of an additional 36 patients with PSVD and 51 patients with cirrhosis were collected for independent model testing. PSVD exhibited the same pronounced PH imaging features as cirrhosis, including grade 1-3 splenomegaly (77/106, 72.6% vs. 67/104, 64.4%; P>0.05), collateral vessels (103/106, 97.2% vs. 94/104, 90.4%; P>0.05), and ascites (35/106, 33.0% vs. 32/104, 30.8%; P>0.05). In addition, PSVD showed more increased small branches of intrahepatic blood vessels than cirrhosis (79/106, 74.5% vs. 41/104, 39.4%; P<0.001). Conversely, PSVD exhibited fewer cirrhosis-specific imaging features, such as reticular delayed enhancement of the hepatic parenchyma (10/48, 20.8% vs. 50/53, 94.3%; P<0.001), RNs (3/48, 6.3% vs. 29/53, 54.7%; P<0.001), and LSN (27/106, 25.5% vs. 75/104, 72.1%; P<0.001). In the validation set, the MRI model [AUC: 0.970, 95% confidence interval (CI): 0.912-1.0], which incorporated four imaging features (reticular delayed enhancement, RNs, LSN and increased small intrahepatic vascular branches), showed superior discriminatory performance compared to the CT model (AUC: 0.825, 95% CI: 0.646-1.0), with a sensitivity of 0.818 and a specificity of 0.889. While the combined model (AUC: 0.97, 95% CI: 0.912-1.0) did not improve upon the performance of the MRI model alone, with sensitivity of 0.821 and specificity of 0.889. Thus, we recommend the MRI model as the preferred modality for diagnosing PSVD. The MRI model also achieved optimal performance in the independent test set, with an AUC of 0.988 (95% CI: 0.967-1), sensitivity of 0.972, and specificity of 0.826.

Patients presenting with severe PH imaging features but lacking typical cirrhosis imaging features should be thoroughly evaluated for PSVD. MRI is the preferred imaging modality. Our MRI-based predictive model reliably differentiates PSVD from cirrhosis, offering a non-invasive method for enhancing the suspicion of PSVD.