Recent developments and future challenges on imaging for stem cell research.

As clinical trials with stem cells for cardiac regenerative therapy move forward, advances in imaging equipment and technique offer powerful methods to evaluate therapeutic efficacy. Methodologies to label stem cells for tracking continue to expand. Non-invasive imaging offers the potential to better understand the interaction of exogenous stem cells with the host to answer questions such as the best cell type(s), timing of delivery, dose, and delivery route. If successful, these techniques may enable individually tailored dosing of stem cell therapeutics. However, techniques that are suitable for animal models of cardiac disease may have hurdles to clinical translation beyond simple biocompatibility issues. Challenges include the high cost of advanced imaging techniques, applicability in acute ischemic disease, and regulatory approval. In this review, we will cover some new imaging techniques and labeling strategies and assess the obstacles to clinical adoption.