Liver Iron Content and Magnetic Resonance: A “Biopsy-Free” Quantification Method and Its Validation
Lorenzo Cinci, Cosimo Nardi, Martina Legato, Valentina Carrai, Valeria Santini, Ginevra Danti, Simone Busoni, Susanna Pucci, Luca Messerini, Linda CalistriBackground/Objectives: Accurate liver iron content (LIC) quantification and monitoring are crucial for managing patients with hematological disorders. Biopsy-based LIC assessment is invasive and prone to sampling errors. This study aimed to develop a simple and safe method for calibrating MR scanner to accurately measure LIC. Methods: Five certified test objects with increasing aqueous Fe3+ solutions were used for R2* relaxometry to create a calibration curve with equation for converting R2* value to iron content (mg/g), using two different MR scanners. Additionally, two sets of test objects (aqueous and gelled solutions to mimic liver tissue) were developed to evaluate the feasibility of using homemade test objects. Our method was compared with two existing methods (Wood et al.’s equation and the Iron Calculator App) in 59 hematological patients, using the certified test object method as reference. We also compared our method with biopsy-based iron quantification (inductively coupled plasma optical emission spectroscopy) in four patients. Results: The equations derived from our homemade test objects were comparable to those from certified test objects across both MRI scanners. The literature methods consistently overestimated LIC compared to our method. For biopsy validation, our method was more accurate in two out of four cases. Conclusions: Our homemade calibration method offers a simple, reliable alternative for LIC quantification. The type of test object (aqueous or gelled) showed no significant difference. While biopsy-based methods remain useful, our MRI-based approach is quicker and avoids the limitations of biopsy sampling. This method, relying on the relationship between iron concentrations and relaxation times, could provide a more comprehensive and accurate assessment of liver iron levels.