Factors Influencing Enhanced Liver Contrast in Super Delayed Phase Gadoxetic Acid MRI
Overview
This study evaluated the effectiveness of super delayed phase (SDP) imaging, acquired 60–120 minutes after gadoxetic acid administration, in improving liver-to-spleen contrast (LSC) in patients with chronic liver disease. The findings indicate that SDP imaging can enhance liver contrast in cases with initially poor LSC at 20 minutes, potentially improving lesion detection in hepatocellular carcinoma (HCC) diagnosis.
Background
Hepatocellular carcinoma (HCC) is a leading cause of cancer mortality worldwide, with noninvasive imaging playing a critical role in diagnosis. Gadoxetate disodium-enhanced MRI is widely used for hepatobiliary phase imaging due to its ability to highlight liver lesions. However, patients with cirrhosis or impaired liver function often show reduced liver contrast, limiting diagnostic accuracy. Extending imaging beyond the standard 20-minute hepatobiliary phase to a super delayed phase (60–120 minutes) has been proposed to improve contrast, but its efficacy and influencing factors require further investigation.
Data Highlights
Parameter
Definition/Value
Standard HBP imaging time
20 minutes post gadoxetic acid injection
Super delayed phase (SDP) imaging time
60–120 minutes post injection
LSC threshold for good contrast
> 1.5
LSC threshold for poor contrast
≤ 1.5
Number of MRI exams reviewed
6933 (2596 patients)
Criteria for additional delayed imaging
Inadequate liver contrast at HBP20
Key Findings
Patients with poor liver-to-spleen contrast (LSC ≤ 1.5) at 20 minutes showed improved LSC in the super delayed phase (60–120 minutes) in a subset of cases.
Super delayed phase imaging was selectively performed based on initial inadequate liver contrast, with timing influenced by clinical workflow and patient consent.
Extended imaging allows increased hepatocellular uptake of gadoxetic acid, enhancing liver parenchymal signal intensity despite impaired liver function.
Patients with advanced liver dysfunction (Child–Pugh B or C) typically exhibit poor LSC at standard HBP, but some benefit from SDP imaging.
Quantitative assessment using regions of interest in liver and spleen enables objective evaluation of contrast improvement between HBP20 and SDP.
Clinical Implications
Incorporating super delayed phase imaging in gadoxetic acid-enhanced MRI protocols can improve liver contrast in patients with chronic liver disease who demonstrate inadequate enhancement at the standard 20-minute hepatobiliary phase. This approach may enhance lesion conspicuity and diagnostic confidence in detecting HCC, particularly in cirrhotic patients with impaired liver function. Clinicians should weigh the benefits against the increased examination time and patient burden when considering SDP imaging.
Conclusion
Super delayed phase imaging at 60–120 minutes post-gadoxetic acid administration improves liver-to-spleen contrast in patients with initially poor hepatobiliary phase enhancement, potentially aiding in the detection of hepatocellular carcinoma. Further studies are warranted to clarify its impact on diagnostic accuracy and clinical outcomes.
References
Kanazawa University Hospital Study 2009-2017 -- Enhanced Liver Contrast in Gadoxetic Acid-Enhanced MRI
LI-RADS v2018 FAQ -- Liver Imaging Reporting and Data System
