Jie Tang PhD, Presenter: Nothing to Disclose

Brian Edward Nett BS, Abstract Co-Author: Nothing to Disclose

Shuai Leng MS, Abstract Co-Author: Nothing to Disclose

Guang-Hong Chen PhD, Abstract Co-Author: Nothing to Disclose

To describe a method of low dose CT myocardial perfusion imaging based on an angularly under-sampled projection acquisition and PICCS image reconstruction, and evaluate its performance in a preliminary porcine study.

Recently an extension to compressed sensing has been proposed in which a prior image is utilized as a constraint in the image reconstruction (i.e. Prior Image Constrained Compressed Sensing - PICCS). In this study, a fully sampled myocardial perfusion data set was acquired under an IRB approved porcine model and using a 64-slice CT scanner. The acquired data set was retrospectively decimated to study how the view angle undersampling scheme can be combined with the PICCS algorithm to achieve radiation dose reduction. In this case the prior image is reconstructed with the whole undersampled data set. After the images were reconstructed, the myocardiac perfusion parameters were derived. The parameters obtained from both fully sampled and undersampled data set were quantified using correlation analysis.

Three regions-of-interest were identified in the myocardium adjacent to the left ventricle. The ability of the under-sampled PICCS acquisitions to portray the temporal enhancement dynamics seen in full-dose, fully-sampled dynamic CT imaging was assessed by comparing quantitative perfusion parameters derived from time-density curves. Dose reduction factors greater than 10 were achieved with an average error in the  time to peak perfusion parameter of less than 5%.

The results of single porcine studies indicate the potential for significant dose reduction (e.g. an order of magnitude) using a gated pulsed acquisition with respect to myocardial perfusion measurements.

 We present a method to overcome a major impediment to the clinical implementation of myocardial CT perfusion by reducing the exposure required by an order of magnitude.

Tang, J, Nett, B, Leng, S, Chen, G, Radiation Dose Reduction in Myocardial CT Perfusion Imaging.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6022189.html