A Practical Approach for a Wide Range of Liver Iron Quantitation Using a Magnetic Resonance Imaging Technique

The goal of this study is to demonstrate a practical magnetic resonance imaging technique for quantifying a wide range of hepatic iron concentration (HIC) for hematologic oncology patients with transfusion iron overload in a routine clinical setting. To cover a wide range of T2* values from hematologic patients, we used a dual-acquisition method with two clinically available acquisition protocols on a 1.5T MRI scanner with different ΔTEs to acquire data in two breath-holds. An in-house image postprocessing software tool was developed to generate T2*, iron maps, and water and fat images, when fat is presented in the liver. The resulting iron maps in DICOM format are transferred to the institutional electronic medical record system for review by radiologists. The measured liver T2* values for 28 patients ranged from 0.56±0.13 to 25.0±2.1 milliseconds. These T2* values corresponded to HIC values ranging from 1.2±0.1 mg/g to 45.0±10.0 mg/g (dry weight). A moderate correlation between overall serum ferritin levels and R2* was found with a correlation coefficient of 0.83. Repeated phantom scans confirmed that the precision of this method is better than 4% for T2* measurements. The dual- acquisition method also improved the ability to quantify HIC of the patients with hepatic steatosis.