- Oral presentation
- Open Access
Flow-Independent Dark-blood DeLayed Enhancement (FIDDLE): validation of a novel black blood technique for the diagnosis of myocardial infarction
© Kim et al. 2016
- Published: 27 January 2016
- Myocardial Infarction
- Framingham Risk Score
- DeLayed Enhancement
- Adequate Blood Flow
- Tissue Enhancement
A fundamental component of the CMR exam is contrast enhanced imaging, which is crucial for delineating diseased from normal tissue. Unfortunately, diseased tissue adjacent to vasculature often remains hidden since there is poor contrast between hyperenhanced tissue and bright blood-pool. Conventional black-blood double-IR methods are not a solution; these were not designed to function after contrast administration since they rely on the long native T1 of blood (~2s at 3T) and adequate blood flow within this time period. We introduce a novel Flow-Independent Dark-blood DeLayed Enhancement technique (FIDDLE) that allows visualization of tissue contrast-enhancement while suppressing blood-pool signal. We validate FIDDLE in an animal model of myocardial infarction (MI) and demonstrate feasibility in patients.
A canine model with variable coronary occlusion times was employed to create a range of MI size/transmurality. Following CMR, hearts were stained with TTC to provide a histopathology reference standard. The main components of FIDDLE are (1) a prep pulse that differentially saturates tissue compared with blood (eg. MT-prep); (2) phase-sensitive IR; and (3) inversion time selection under condition: blood MZ < tissue MZ. CMR was performed acutely or chronically at 3T. FIDDLE and delayed-enhancement CMR (DE-CMR) were acquired using matched settings (slice thickness, 7 mm; inplane resolution, 1.2 × 1.0 mm; etc) ~15 minutes after contrast (0.2 mmol/kg). We enrolled patients with enyzmatically confirmed MI and identifiable infarct-related-artery by X-ray angiography, as well as controls with Framingham Risk Score = 0. The patient CMR protocol was similar to that in canines. FIDDLE & DE-CMR analysis were performed separately and masked to identity and pathology (canines) or angiography results (patients).
Diagnostic Performance in Canines
Subendocardial MI (transmurality < 25%)
We demonstrate that FIDDLE is more sensitive and accurate than standard DE-CMR for the diagnosis of MI. Although validation and feasibility is demonstrated for diagnosis of MI, the technique is easily transferable beyond cardiac imaging and additional applications are expected in other settings (such as vascular wall imaging) where there is need to distinguish abnormal tissue enhancement from blood-pool.
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