Abstract 15708: In Both Hypertrophic And Dilated Cardiomyopathy, Non-contrast T1 Mapping Provides Myocardial Tissue Characterization Beyond That Achieved By Late Gadolinium Enhancement.
Introduction: Non contrast T1 mapping provides a novel quantitative method for myocardial tissue characterization. Although T1 mapping has been investigated in ischaemic heart disease, its role in non-ischemic disease, such as hypertrophic and dilated cardiomyopathy (HCM, DCM), remains to be explored. We hypothesize that T1 mapping offers an alternative to late gadolinium enhancement (LGE) techniques, providing additional diagnostic information in HCM and DCM.
Methods: CMR imaging (3T Siemens Trio) was done on 25 HCM, 11 DCM and 11 normal subjects. Matching short axis slices were acquired for cine, T1 mapping (short modified look locker inversion recovery - ShMOLLI - sequence) and LGE imaging (0.1 mmol/kg).
Results: On a patient, and on a segmental basis, mean T1 relaxation time was significantly elevated in HCM and DCM (segmental analysis: HCM 1208±47ms, DCM 1224±69ms, normal 1172±45ms, p<0.05). T1 values were significantly higher in segments with LGE than in those without (HCM with LGE 1229±42ms vs no LGE 1193±44ms, p<0.05; DCM with LGE 1252±87ms vs no LGE 1213±55ms p<0.05). However, even in segments unaffected by LGE, T1 values were significantly higher than normal (p<0.001). On a segmental basis, there was a weak, but significant, correlation between mean T1 and LGE (r2= 0.1, p< 0.001).In addition, T1 was elevated irrespective of wall thickness in HCM and DCM. However, there was a positive correlation between T1 values and wall thickness in HCM. In DCM, there was a negative correlation.Figure shows examples of T1 maps and LGE images.
Conclusion: In HCM and DCM, non-contrast T1 mapping detects underlying disease processes which to some extent reflect the presence of LGE. Importantly, T1 mapping also detects myocardial changes in regions where LGE imaging does not. The likely mechanism is the presence of diffuse fibrosis. Hence, T1 mapping may become an important new tool for understanding disease mechanisms, therapy monitoring and prognostic assessment in HCM and DCM.
- © 2011 by American Heart Association, Inc.