Table 3. Pros and cons of the different CT techniques of myocardial ischemia.

Techniques	Pros	Cons
CT perfusion	Hemodynamic significance of stenosis;	Not widely available;
	Effective reclassification of stenotic lesions;	Advanced skills for performance, post-processing, interpretation;
	More cost-effective than SPECT;	Higher radiation;
	Useful in heavy calcium or stent	Larger volume of iodinated contrast;
		Higher cost than CTA alone;
		Limited in balanced ischemia
CT-FFR	Hemodynamic significance of stenosis;	Accuracy lower in borderline values (0.7 to 0.8);
	Effective gatekeeper for ICA;	Modest performance in non-culprit lesions in recent STEMI;
	Lower cost and improved outcomes compared to ICA and visual guidance;	Added cost;
	Biomechanical information on plaques;	Limited availability;
	Effective in balanced ischemia;	Long post-processing time;
	No additional radiation;	High image quality required with low motion;
	No additional contrast	Limited in calcium, stents and bypass grafts
TAG	Hemodynamic significance of stenosis;	No outcome data yet;
	No additional radiation;	Requires wide array/volume scanner
	No additional contrast;
	No complex post-processing;
	No additional cost

CT-FFR, computed tomography-derived fractional flow reserve; SPECT, single-photon emission computed tomography; CTA, computed tomography angiogram; ICA, invasive coronary angiogram; STEMI, ST-elevation myocardial infarction; TAG, transluminal attenuation gradient.