- Workshop presentation
- Open Access
Fast, heart-rate independent, whole-heart, free-breathing, three-dimensional myocardial BOLD MRI at 3T with simultaneous 13N-ammonia PET validation in canines
© Yang et al. 2016
- Published: 27 January 2016
- Myocardial Perfusion
- Imaging Myocardial Perfusion
- Myocardial Blood Flow
- Bold Response
- Adenosine Stress
Myocardial BOLD MRI is a non-contrast approach for examining myocardial perfusion. Although recent developments have shown promising technical advancements, current myocardial BOLD MR methods are still limited by: (a) poor spatial coverage; (b) imaging confounders; and (c) imaging artifacts, particularly at 3T. To address these limitations, we developed a heart-rate independent, free-breathing 3D T2 mapping technique at 3T that utilizes near 100% imaging efficiency, which can be completed within 3 minutes. We tested our method in a canine model and validated our findings with simultaneously acquired 13N-ammonia PET perfusion data in a whole-body PET/MR system.
Canines with and without LAD stenosis (n = 11) were studied in a PET/MR system. The proposed sequence was prescribed at rest and under adenosine stress (140 mg/min/kg). Dynamic 13N-ammonia PET scans were acquired for validation purpose. PET images were analyzed using qPET software. In healthy dogs, mean myocardial T2 (T2avg) were measured at rest and stress and mean myocardial blood flow (Qavg) were derived from PET images in the corresponding slices. Myocardial BOLD Response (MBOLDR = T2avg (stress):T2avg(rest)) and perfusion reserve (MPR = Qavg (stress):Qavg(rest)) were computed and compared. In the stenosis study, the affected regions were identified from the PET images and matched to the corresponding slices in BOLD data. Mean myocardial T2 and myocardial perfusion were measured at rest and stress in the affected and remote territories. MBOLDR and MPR from affected and remote regions were computed and compared against to each other.
The proposed BOLD CMR approach permits rapid whole LV assessment of BOLD changes between rest and adenosine stress. The BOLD responses were very closely correlated with PET perfusion, suggesting that the proposed BOLD CMR method is a viable approach for imaging myocardial perfusion. The method remains to be validated in patients.
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