Clinical Scorecard: Noninvasive Assessment of Hepatic Extracellular Volume via Photon-Counting CT for Risk Stratification in Clinically Significant Portal Hypertension: A Prospective Cohort Analysis

At a Glance

Key Highlights

• CSPH marks a critical transition in compensated advanced chronic liver disease, increasing risk of severe complications.
• Hepatic venous pressure gradient (HVPG) measurement is the reference standard but limited by invasiveness and availability.
• PCCT-derived hepatic extracellular volume (ECV) offers a noninvasive, reproducible imaging biomarker to stratify CSPH risk complementing liver stiffness measurement (LSM).

Guideline-Based Recommendations

Diagnosis

• Use noninvasive liver disease assessment (NILDA) including liver stiffness measurement (LSM) as pragmatic surrogates for CSPH risk stratification.
• Consider PCCT-derived hepatic ECV quantification as an adjunct imaging biomarker to improve risk stratification in patients undergoing routine liver imaging.

Management

• Monitor patients with compensated advanced chronic liver disease (cACLD) for transition to CSPH using noninvasive surrogates.
• Incorporate imaging-based ECV measurement to complement elastography and histology in clinical decision-making.

Monitoring & Follow-up

• Regular surveillance imaging for hepatocellular carcinoma (HCC) can be leveraged to assess hepatic ECV without additional scans.
• Use LSM thresholds (≥ 25 kPa rule-in, ≤ 15 kPa rule-out) alongside ECV to monitor fibrosis progression and portal hypertension risk.

Risks

• Limitations of LSM include operator dependency and reduced reliability in obesity or ascites.
• Invasive HVPG measurement carries procedural risks and limited availability, underscoring need for noninvasive alternatives.

Patient & Prescribing Data

Adults with chronic liver disease undergoing fibrosis and portal hypertension risk assessment

PCCT-derived hepatic ECV measurement provides an objective, reproducible biomarker that may guide risk stratification and management decisions without additional invasive procedures.

Clinical Best Practices

• Perform PCCT imaging with delayed equilibrium phase iodine mapping for accurate hepatic ECV quantification.
• Place multiple regions of interest in predefined liver segments avoiding vessels and artifacts for iodine density measurement.
• Calculate hepatic ECV using iodine density ratios corrected for hematocrit obtained within 24 hours of imaging.
• Integrate PCCT-derived ECV data with established noninvasive markers such as LSM and histology for comprehensive fibrosis and CSPH assessment.

References

• Baveno VII Consensus on Portal Hypertension
• AASLD Practice Guidance on Portal Hypertension
• Photon-counting CT in Myocardial Imaging