Myocardial ischemia: Effect of scan timing
49 yo M presents with chest pain. CT PE obtained, shows LV hypertrophy without obvious perfusion defect.
Abdominal CT from 3 weeks prior (no intervening cardiac intervention) shows a clear LV anteroseptal perfusion defect. Patient known to have an old anteroseptal MI with a chronically occluded LAD.
Myocardial perfusion defects are much more obvious in 40-70 second scans in my experience, and can be easily missed on CT PE studies which are done earlier.