MRI Iron Quantification Calculator
Convert cardiac and liver MRI T2*/R2* values into tissue iron concentration using validated calibrations, for monitoring iron overload.
What is MRI Iron?
MRI iron quantification estimates tissue iron from relaxometry. Cardiac T2* assesses myocardial iron (normal >20 ms), while liver T2*/R2* values convert to liver iron concentration (LIC). This calculator applies validated Carpenter, Wood, and Storey calibrations to report iron levels and severity for thalassemia, sickle cell disease, and transfusional overload.
MRI Iron Quantification
T2* and R2* based iron concentration calculation
How to Use
- Select the organ tab (Heart or Liver) for your measurement
- Enter your T2* value in milliseconds (ms) or R2* value in Hertz (Hz)
- The iron concentration will be calculated automatically
- Results are based on validated calibration formulas from published studies
Cardiac T2*
Pennell 2013 (AHA) 3-Tier Risk Model:
T2* > 20 ms: Normal (Low Risk) | T2* 10-20 ms: Mild to Moderate (Intermediate Risk) | T2* < 10 ms: Severe (High Risk)
1. Pennell, DJ et al. (2013). Cardiovascular function and treatment in β-thalassemia major: AHA Scientific Statement. Circulation, 128, 3:281-308.
2. Anderson, LJ (2011). Assessment of iron overload with T2* magnetic resonance imaging. Prog Cardiovasc Dis, 54, 3:287-94.
3. Carpenter, JP (2011). On T2* magnetic resonance and cardiac iron. Circulation, 123, 14:1519-28.
4. Kirk, P et al. (2009). Cardiac T2* MRI for prediction of cardiac complications in thalassemia major. Circulation, 120, 20:1961-8.
Liver T2* 1.5T
Normal: < 1.8 | Borderline: 1.8 – < 3.2 | Mild: 3.2 – < 7.0 | Moderate: 7.0 – < 15.0 | Severe: ≥ 15.0 mg/g
1. Wood, JC, Enriquez, C, Ghugre, N, Tyzka, JM, Carson, S, Nelson, MD, Coates, TD (2005). MRI R2 and R2* mapping accurately estimates hepatic iron concentration in transfusion-dependent thalassemia and sickle cell disease patients. Blood, 106, 4:1460-5.
Severity thresholds derived from Wood 2005 calibration data.
Liver R2* 1.5T
Normal: < 1.8 | Borderline: 1.8 – < 3.2 | Mild: 3.2 – < 7.0 | Moderate: 7.0 – < 15.0 | Severe: ≥ 15.0 mg/g
1. Wood, JC, Enriquez, C, Ghugre, N, Tyzka, JM, Carson, S, Nelson, MD, Coates, TD (2005). MRI R2 and R2* mapping accurately estimates hepatic iron concentration in transfusion-dependent thalassemia and sickle cell disease patients. Blood, 106, 4:1460-5.
Severity thresholds derived from Wood 2005 calibration data.
Liver T2* 3T
1. Storey P, Thompson AA, Carqueville CL, Wood JC, de Freitas RA, Rigsby CK. R2* imaging of transfusional iron burden at 3T and comparison with 1.5T. J Magn Reson Imaging. 2007 Mar;25(3):540-7. PubMed PMID: 17326089; PubMed Central PMCID: PMC2884049.
Liver R2* 3T
1. Storey P, Thompson AA, Carqueville CL, Wood JC, de Freitas RA, Rigsby CK. R2* imaging of transfusional iron burden at 3T and comparison with 1.5T. J Magn Reson Imaging. 2007 Mar;25(3):540-7. PubMed PMID: 17326089; PubMed Central PMCID: PMC2884049.
Frequently asked questions
What does cardiac T2* tell you about iron?
Cardiac (myocardial) T2* reflects iron loading of the heart. A T2* above 20 ms is considered normal, 10–20 ms indicates mild-to-moderate iron, and below 10 ms indicates severe cardiac iron with high risk of heart failure and arrhythmia.
How is liver iron concentration (LIC) estimated?
LIC is derived from liver T2* or R2* using validated calibration formulas (e.g., Wood 2005). Higher R2* (or lower T2*) corresponds to higher liver iron. Results are reported in mg Fe per gram dry weight, with thresholds for normal, mild, moderate, and severe loading.
Why use MRI instead of ferritin or biopsy?
MRI relaxometry is noninvasive, reproducible, and organ-specific, allowing separate assessment of heart and liver iron. Serum ferritin correlates only loosely with tissue iron, and liver biopsy is invasive and prone to sampling error, so MRI has become the standard for monitoring iron overload.
Which formulas does this calculator use?
It uses peer-reviewed calibrations including Carpenter (cardiac), Wood (liver, 1.5T), and Storey (liver, 3T), matched to field strength and organ. References are listed alongside each measurement on the page.