Quantitative assessment of myocardial T2 relaxation times in cardiac amyloidosis

To evaluate cardiac MRI (CMR) in the diagnosis of cardiac amyloidosis by comparing the T2 relaxation times of left ventricular myocardium in a pilot patient group to a normal range established in healthy controls.

Forty-nine patients with suspected amyloidosis-related cardiomyopathy underwent comprehensive CMR examination, which included assessment of myocardial T2 relaxation times, ventricular function, resting myocardial perfusion, and late gadolinium enhancement (LGE) imaging. T2-weighted basal, mid, and apical left ventricular slices were acquired in each patient using a multislice T2 magnetization preparation spiral sequence. Slice averaged T2 relaxation times were subsequently calculated offline and compared to the previously established normal range.

Twelve of the 49 patients were confirmed to have cardiac amyloidosis by biopsy. There was no difference in mean T2 relaxation times between the amyloid cases and normal controls (51.3 +/- 8.1 vs. 52.1 +/- 3.1 msec, P = 0.63). Eleven of the 12 amyloid patients had abnormal findings by CMR, eight having LGE involving either ventricles or atria and four demonstrating resting subendocardial perfusion defects.

CMR is a potentially valuable tool in the diagnosis of cardiac amyloidosis. However, calculation of myocardial T2 relaxation times does not appear useful in distinguishing areas of amyloid deposition from normal myocardium.