Comparison of the Diagnostic Performance of Native Non-Contrast T1 Mapping versus Flow-independent Dark-blood Delayed Enhancement (FIDDLE) CMR for the Diagnosis of Chronic Myocardial Infarction

• Applicant: Dr. Céleste Marie Chevalier
• Subject Area: Cardiology, Angiology
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 524025195

Delayed Enhancement Cardiovascular Magnetic Resonance (DE-CMR), which requires the use of gadolinium-based contrast agents, is considered the gold standard for the detection and quantification of chronic myocardial infarction. The advantage of DE-CMR is that it can identify subendocardial infarcts, which are routinely missed by other imaging modalities such as echocardiography and SPECT. Clinically, the diagnosis of even small infarcts is essential because they, too, are associated with worse prognosis. However, in very small subendocardial infarcts, conventional DE-CMR is limited by the low contrast between blood and infarcted myocardium, since both the infarcted myocardium and the blood pool appear hyperintense. In contrast, the new Flow-Independent Dark-Blood Delayed Enhancement (FIDDLE) technique visualizes infarcted myocardium as a hyperintense area while simultaneously suppressing the blood pool signal, which thus appears hypointense and improves the delineation between myocardium and adjacent blood. Based on this, studies on the detection of subendocardial infarcts showed an improved diagnostic performance of FIDDLE compared with conventional DE-CMR. Previous studies have also suggested that native T1 mapping methods can be used to diagnose myocardial infarction without the need for contrast agents, thus bypassing the potential safety concerns related to contrast media. However, native T1 measurements based on steady-state free precession (SSFP) protocols can be affected by the presence of intramyocardial fat, resulting in an elevation or reduction of T1 dependent on different factors. An elevation of T1 could be misinterpreted for replacement fibrosis. A pilot study by the Duke Cardiovascular Magnetic Resonance Center (DCMRC) could show that, in the presence of intramyocardial fat in the form of lipomatous metaplasia, native T1 mapping is not reliable for the direct detection of fibrosis in chronic infarcts. To date, no studies have compared the diagnostic accuracy of native T1 mapping, DE-CMR, and FIDDLE for the diagnosis of chronic myocardial infarction. Based on the preliminary work by the DCMRC, we now propose a comprehensive study examining the diagnostic performance of all three methods, including FIDDLE. The combination of the techniques will allow us to focus on subendocardial infarcts.

• DFG Programme: WBP Fellowship
• International Connection: USA
• Host: Professor Raymond Kim, Ph.D.