These tests look at completely different things, so yes. Its alot to break down but basically.. Stress tests look at electricity and wall motion. Ct angiograms look at blood flow. Contrast mri and nuclear medicine looks at perfusion (how well muscles soak up blood).
So you can have a 48% reduction in blood flow, resulting in a 68% reduction in pumping action/wall motion and a 20% loss of perfusion all in 1, yes.