Figure 4

Ischemia by Treadmill Stress CMR and SPECT. Rest and stress CMR and SPECT images in the same patient of Fig. 3 both demonstrate myocardial ischemia, with corresponding obstructive coronary artery disease by angiography. Resting diastolic (A) and systolic (B) cine frames vs. comparable post-exercise cine frames (F, G) show stress-induced inferior wall contractile dysfunction (G, arrowhead). Inferior ischemia is also demonstrated by CMR perfusion imaging (C-rest perfusion vs. H-stress perfusion, arrowhead). Prior MI in the anteroseptum can be seen on late post-gadolinium imaging (E); note some fatty replacement in the infarct region evident as bright intramyocardial signal on noncontrast gradient echo cine frame in panel B. Rest Tc-99 m perfusion SPECT (D) suggests normal perfusion, though somewhat obscured by adjacent bowel uptake; stress Tc-99m perfusion SPECT shows inferior wall defect (I, arrowhead). The patient went on to invasive angiography that showed an occluded right coronary artery (J, arrow) with some left-to-right collateral flow.