How to cite: Golay, X. “A Calibration Tool for ADC Measurements in Prostate Cancer.” September 15, 2025. Accessed Dec 2025. https://grandroundsinurology.com/a-calibration-tool-for-adc-measurements-in-prostate-cancer/
Summary
Xavier Golay, MS, PhD, Honorary Professor, University College London, London, United Kingdom, and CEO of Gold Standard Phantoms, Sheffield, United Kingdom, presents a phantom-based calibration method for apparent diffusion coefficient (ADC) measurement. ADC is widely used in prostate cancer imaging within prostate imaging reporting and data system (PI-RADS) multiparametric magnetic resonance imaging (MRI) protocols. Still, variability across scanners, field strengths, and acquisition settings limits its reproducibility and utility in longitudinal or multicenter studies.
Dr. Golay shares that MRI has traditionally been designed as a “camera” for producing images rather than a calibrated measurement instrument. As a result, ADC values may differ significantly between scanners. Golay emphasizes that quantitative MRI requires calibration against standards, including bias evaluation, linearity, repeatability, and reproducibility.
To address this, Dr. Golay’s team developed an MRI phantom containing vials with International System of Units (SI) -traceable diffusivity values, embedded in polyurethane with susceptibility matched to tissue, along with fiber optic probes for precise temperature monitoring. Scanning the phantom simultaneously with patients enables voxel-by-voxel calibration and propagation of measurement uncertainty into ADC maps. In a proof-of-principle study, calibrated ADC maps showed improved consistency across repeat scans and scanners. Calibration reduced slope-dependent bias, particularly when diffusion-weighted imaging parameters were altered.
Future plans include a 60-patient study using an integrated phantom with embedded temperature sensors across multiple scanners. Early results demonstrate reproducible ADC maps across three MRI systems, highlighting the feasibility of standardized diffusion MRI in clinical and research settings.
Dr. Golay argues that calibrated ADC maps may position diffusion MRI as a precision measurement tool rather than a purely qualitative imaging technique.
The Global Summit on Precision Diagnosis and Treatment of Prostate Cancer is a unique multi-disciplinary forum organized to inform the key health care stakeholders about the emerging advances in clinical cases and research and create a consensus-based vision for the future of precision care and educational and research strategy for its realization. The mission of the Summit is to fill the currently existing gap between the key experts of in vivo imaging, the world authorities in the in vitro fluid- and tissue-based molecular diagnostics, including genomics, and thought leaders in the development of novel observation strategies (e.g., active surveillance, or AS) and therapeutic interventions.
ABOUT THE AUTHOR
Xavier Golay, MS, PhD, is the Founder and CEO of Gold Standard Phantoms in Sheffield, England. Dr. Golay also serves as the Director of Quantitative Imaging at Bioxydyn Limited and an Honorary Professor of MRI Physics at the University College London in England. His research interests include the development of MRI as a translational tool for neurological diseases, measuring identical image-based biomarkers from mouse to human, and from the laboratory to the clinical settings.
