Liver R2* threshold to predict the failure of MR elastography at 3T: SE-EPI versus GRE sequences

Area of Science:

• Radiology
• Medical Imaging
• Hepatology

Background:

• Liver iron overload is a primary cause of magnetic resonance elastography (MRE) failure.
• Accurate MRE is crucial for liver fibrosis assessment.
• Identifying predictors of MRE failure is essential for reliable diagnosis.

Purpose of the Study:

• To establish R2* thresholds that predict MRE failure in the presence of liver iron overload.
• To evaluate these thresholds for both 2D gradient-recalled echo (GRE) and spin-echo echo-planar imaging (SE-EPI) MRE sequences at 3 Tesla.

Main Methods:

• Retrospective analysis of 221 patients undergoing GRE MRE, SE-EPI MRE, and R2* quantification.
• R2* values, a surrogate for liver iron concentration (LIC), were measured.
• Receiver operating characteristic (ROC) curve analysis determined the predictive ability of R2* for MRE failure.

Main Results:

• Iron-related MRE failure rates were 62.9% for GRE MRE and 10.0% for SE-EPI MRE.
• An R2* cutoff of 101 s⁻¹ predicted GRE MRE failure (AUC=0.97).
• An R2* cutoff of 289 s⁻¹ predicted SE-EPI MRE failure (AUC=0.89).

Conclusions:

• Liver R2* effectively predicts MRE examination failure caused by iron deposition at 3 T.
• Specific R2* thresholds can differentiate between MRE success and failure due to iron overload for different MRE sequences.