Quantitative MRI biomarker for classification of clinically significant prostate cancer: calibration for reproducibility across echo times

Motivation: Restriction Spectrum Imaging restriction score (RSIrs) is a quantitative biomarker for detection of clinically significant prostate cancer. However, magnitude of RSIrs is influenced by imaging parameters, including echo time (TE). Goal(s): We introduce a calibration technique to generate consistent RSIrs biomarker values for data acquired with different TEs. Approach: We demonstrate a partial linear relationship between RSIrs and TE and compare calibrated to reference RSIrs values at two TEsResults: The proposed calibration reduced bias between calibrated and reference RSIrs values. Impact: Restriction Spectrum Imaging restriction score (RSIrs) is a quantitative MRI biomarker of clinically significant prostate cancer, but RSIrs values are dependent on echo time. This study introduces an approach to calibrate RSIrs for echo time variations and yield reproducible results.