Abstract 18741: Spectral CT Imaging of Coronary Ruptured Plaque: A Step Closer to the Clinic
Background: Spectral CT extends traditional CT coronary imaging by offering the potential to detect ruptured plaque microthrombus with novel fibrin-specific nanoparticles without coronary calcium interference.
Objective: The goals of the present study were to advance the safety and efficacy Spectral CT demonstrating the efficacy of fibrin detection in vivo, by improving contrast imaging SNR to reduce radiation dosimetry and heavy metal contrast requirements.
Methods and Results: Bismuth (NanoKB) and gold (NanoKA) (∼185±20 nm) polysorbate nanocolloids containing 50 and 4 v/v% metal content were prepared. NanoKB targeted to fibrin acellular phantoms and human carotid specimens revealed high contrast signal and intravascular constraint. Anti-human fibrin NanoKB was targeted to rabbit thrombus and imaged. Spectral CT readily detected the NanoKB bound at physiologic fibrin presentation density. In a second study, the total bioelimination of bismuth from mice (n=6) injected IV was studied. Weekly analysis by ICP revealed that 95% of the metal was cleared in 7 days and more 96% at 14 days (p<0.05). Further image reconstruction research comparing iterative versus classic filtered back projection techniques improved contrast to noise by 3 to 5 fold in a series of in vitro and in vivo studies. Utilizing this reconstruction improvement, NanoKA, containing only 4% gold (v/v) was developed and detected with high contrast when bound to fibrin. NanoKA utilized only 1/10th of the metal in NanoKB.
Conclusions: The expansion of new agents, the rapid bioelimination of injected heavy metals in parallel with improved Spectral CT imaging technique, and the related X-ray dose reduction opportunity continue to encourage the advancement of this technology to the ED where quick differentiation of patients with chest pain due to coronary plaque rupture from others with noncoronary sources of symptoms will markedly change our medical evaluation paradigm.
- © 2010 by American Heart Association, Inc.