CMR in Hemochromotosis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

There are multiple iron overload states:

• hemochromatosis
• thalassemia major
• sideroblastic anemia
• chronic hemolytic anemia
• chronic liver disease.

Hemochromatosis

ACC/AHA Guidelines- ACCF/ACR/AHA/NASCI/SCMR 2010 Expert Consensus Document on Cardiovascular Magnetic Resonance (DO NOT EDIT)

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CMR may be used for assessment of patients with LV dysfunction or hypertrophy or suspected forms of cardiac injury not related to ischemic heart disease. When the diagnosis is unclear, CMR may be considered to identify the etiology of cardiac dysfunction in patients presenting with heart failure, including evaluation of dilated cardiomyopathy in the setting of normal coronary arteries, patients with positive cardiac enzymes without obstructive atherosclerosis on angiography, patients suspected of amyloidosis or other infiltrative diseases, hypertrophic cardiomyopathy, arrhythmogenic right ventricular dysplasia, or syncope or ventricular arrhythmia.

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On cardiac MR, patients with hemochromatosis have very low signal intensity in the myocardium due to the effects of iron deposits.

T2 imaging can be highly sensitive in detecting myocardial iron deposition based on study by Anderson and colleagues. - T2* values are substantially reduced, from normal values of 50msec or greater to less than 20msec. Lower T2* can indicate worsening LV function.

Late signs of iron toxicity include left ventricular systolic dysfunction.

The importance of this is that early identification of iron-deposition cardiomyopathy enables early intensification of iron chelation therapy which could potentially improve a patient's chance of survivial.

References

Cheong et al. Evaluation of Myocardial Iron Overload by T2 Cardiovascular Magnetic Resonance Imaging. Images in Cardiovascular Medicine. 2005. 32; 448.