On the Use of Micro-Computed Tomography for Pre-Clinical Testing of Cardiovascular Devices that Treat Intravascular Calcium

Abstract

Micro-computed tomography (µCT) is a powerful, non-destructive tool that generates three-dimensional images of objects using penetrative X-rays. µCT is useful when imaging hardened, biological tissues and is particularly useful when studying the efficacy of cardiovascular devices for the treatment of intravascular calcium (IVC). IVC is an advanced state of atherosclerosis that commonly afflicts the elderly and is associated with vessel hardening (i.e., calcification) and narrowing. If left untreated, adverse events due to IVC include myocardial infarction, stroke, and amputation. However, because of its high strength and the fragility of the surrounding artery, IVC is difficult to treat. Further, device innovations are stymied because of the lack of readily available, pre-clinical models. Currently, the best model of IVC is diseased cadaveric and endarterectomy tissue, but the morphological inconsistencies of these tissues require a standardized approach when used for evaluating IVC treatments. We report a generalized approach that employs µCT to enable qualitative and quantitative analyses of the treatment effect of new devices on IVC tissue. This approach consists of 1) specimen screening, storage, and preparation, 2) pre-, peri-, and post-treatment µCT imaging, and 3) image analysis of IVC morphology and treatment effect. Various examples are provided to guide future bioengineering and medical device testing applications in this space.