of Work: T1-201 and Tc-MIBI imaging of the myocardium are two very commonly employed clinical tests to assess myocardial perfusion and viability. Recently it has been proposed to use electrocardiogram-gating techniques, to """"""""gate"""""""" these images in order to measure cardiac ventricular function. This ability to simultaneously measure both function and perfusion, without the need for additional imaging or injection of radioisotope, would have a profound impact on cost and clinical efficacy. Reports have already appeared in the literature on methods to quantitate function from the low-noise, high-resolution images obtainable from Tc-MIBi. However, the more commonly used perfusion agent T1-201 gives images with much higher noise levels, making quantification of function problematic. One of the difficulties is that poor contrast (associated with bloodpool activity and trabeculae) makes endocardial borders hard to trace. We proposed using a new method for computation of ejection fraction, based on epicardial borders, using the constraint that myocardial mass must be constant. This proposal is being tested, using an in-house-developed image- processing system that uses dynamic programming to track the endo- and epicardial borders. Preliminary patient studies indicate that this method may permit extraction of functional information even from noisy T1-201 studies. A description and validation of the technique will be presented orally and in abstract form. The full article describing the technique and its preliminary validation is in preparation.
