Shorter difference between myocardium and blood optimal inversion time suggests diffuse fibrosis in dilated cardiomyopathy.

PURPOSE

To find evidence of diffuse fibrosis in dilated cardiomyopathy (DCM) patients by comparing measurements on clinical late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) studies between DCM and healthy subjects.

MATERIALS AND METHODS

LGE-CMR and the Look-Locker images from 20 DCM patients and 17 healthy controls were analyzed. Blood signal-to-noise ratio (SNR), myocardium SNR, and blood-to-myocardium contrast-to-noise ratio (CNR) were measured on the LGE-CMR images. The optimal inversion time (TI) to null blood and myocardium was determined on the Look-Locker images. The postcontrast T(1) was estimated using a phantom study that correlated optimal TI and heart rate to T(1).

RESULTS

The blood SNR was lower, myocardium SNR was higher, and the blood-to-myocardium CNR was lower (6.6 +/- 0.7 vs. 10.3 +/- 0.9, P = 0.004) on DCM LGE-CMR images as compared to controls. The blood-myocardium optimal TI difference (DeltaTI) was lower (38 +/- 2 msec vs. 55 +/- 3 msec, P < 0.001) in DCM, and the estimated blood-myocardium T(1) difference (DeltaT(1)) (116 +/- 6 msec vs. 152 +/- 8 msec, P = 0.001) was also lower.

CONCLUSION

DCM patients have reduced blood-myocardium DeltaTI and DeltaT(1), and lower CNR as compared to controls, suggesting the presence of diffuse fibrosis. This may impact the interpretation of LGE data.