Optimized cardiac CEST MRI for assessment of metabolic activity in the heart
KeywordsCreatine Kinase Respiratory Motion Infarct Region Remote Myocardium Chronic Myocardial Infarction
It has been previously shown that cardiac dysfunction is associated with myocardial ATP loss. The synthesis of myocardial ATP involves the conversion of phosphocreatine to creatine catalyzed by creatine kinase. CEST has been used to map creatine distribution in the myocardium to assess metabolic activity in animals . However, the previous approach requires lengthy scan time (50 min), which needs to be reduced considerably for human application.
In this work, we developed an optimized cardiac CEST technique with dramatically shortened scan time (by 10-fold), improved motion registration and CEST signal calculation, and tested its feasibility to detect chronic myocardial infarction in porcine model and also in a patient for the first time. LGE imaging was used as reference.
Four female Yucatan porcine and one patient with chronic myocardial infarction were studied on a 3T Siemens Verio clinical scanner. LGE images were acquired as reference for myocardial infarction.
Fig. 2(c) quantitatively compares the CEST signals in the LGE positive and negative regions in base, mid and apex slices in the porcine model. The CEST signal is significantly reduced in the infarct region (9.5% ± 1.9%), compared to healthy remote myocardium (15.5% ± 2.2%), p < 0.00005. In the patient, CEST signal in the infarct region is 8.4% while that in the healthy myocardium is 16.2%.
We developed a clinically feasible cardiac CEST approach and performed preliminary validation studies in porcine with chronic myocardial infarction. The study also shows the feasibility of cardiac CEST imaging in a patient, for the first time. This technique has the potential to provide information on metabolic abnormalities for cardiac diseases.
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.