T1 mapping shows increased extracellular matrix size in the myocardium due to amyloid depositions.

Amyloidosis is a systemic infiltrative disorder in which insoluble protein fibrils are deposited in the extracellular matrix (ECM). The prognosis is predominantly determined by cardiac involvement because the amyloid depositions lead to a restrictive cardiomyopathy. Although endomyocardial biopsy is the gold standard for diagnosing cardiac amyloidosis, the associated risk for complications favors a noninvasive approach by using various cardiac imaging methods, whereas tissue diagnosis is made on a noncardiac biopsy. Accurate diagnosis of cardiac amyloidosis becomes difficult when a secondary cause of myocardial wall thickening (eg, hypertension) is present as well. Cardiac MRI is an excellent tool for assessment of systolic and diastolic function, myocardial thickness, and amyloid deposition with late gadolinium enhancement imaging.1 Late gadolinium enhancement imaging is a qualitative technique, which relies on the presence of normal myocardium to visualize infiltrated, enhanced tissue. Therefore, diffuse deposition of amyloid is difficult to highlight, because regional differences in signal intensities may be absent. T1-mapping is a cardiac MR technique, which allows absolute quantification of T1 values of the myocardium and enables assessment of ECM expansion present in cardiac amyloidosis. A 71-year-old man with a medical history of hypertension presented with suspicion of congestive heart failure. A 12-lead electrocardiography showed atrial fibrillation and