CT-based hepatic and splenic extracellular volume fraction and iodine washout rate for noninvasive assessment of portal hypertension: a preliminary study

In cirrhotic patients, the severity of portal hypertension (PH) directly correlates with the risk of decompensation. The hepatic venous pressure gradient (HVPG) is critical for staging and prognostic prediction of PH, but it is invasive. Non-invasive assessment of PH remains an unmet clinical need. Therefore, this study aimed to evaluate whether multiphasic computed tomography (CT)-derived extracellular volume fraction (ECV) of the liver and spleen, and the liver iodine washout rate (IWR), could serve as noninvasive biomarkers for clinically significant PH (CSPH, defined as HVPG ≥ 10 mmHg) and severe PH (defined as HVPG ≥ 16 mmHg). This retrospective study included 127 participants: 76 cirrhotic patients with CSPH and 51 control individuals with normal liver (as determined by clinical data, laboratory tests and imaging). All participants underwent contrast-enhanced CT. Pearson correlations between CT parameters and HVPG were analyzed. The diagnostic performance of these parameters in differentiating patients with CSPH from control individuals, and non-severe PH (HVPG < 16 mmHg) from severe PH was assessed using the areas under the receiver operating characteristic curve (AUC). The CT parameters significantly differed between CSPH patients and control individuals (P < 0.05). ECVliver, ECVspleen, and IWRliver were correlated with HVPG (r = 0.29, 0.41, and − 0.45, respectively; all P < 0.05). Both ECVspleen and IWRliver independently predicted PH severity (P < 0.05), and showed excellent diagnostic accuracy for CSPH (AUC = 0.981 and 0.953, respectively), outperforming ECVliver (AUC = 0.706, P < 0.001). For distinguishing non-severe PH from severe PH, ECVspleen and IWRliver achieved AUC values of 0.718 and 0.722, respectively, with their combination improving diagnostic accuracy (AUC = 0.832, sensitivity = 90.00%, and specificity = 69.44%). The CT parameters ECVspleen and IWRliver can serve as promising noninvasive tools for assessing PH severity. Further validation in broader PH cohorts is warranted.