Day 1 - rest phase: patient was injected with Tc99 m - MIBI during rest. Day 2 - stress phase: patient was injected with Tc99 m - MIBI during stress test with physical exercise or Dipyridamole transfusion (if patient is contraindicated or unable to perform physical exercise) * Facility: SPECT Gamma camera Infinia from GE (USA) and specialized image processing software: GE's Myometrix and Cedar Sinai's QGS / QPS.