While “on-line”<unk> <unk> c is somewhat cumbersome to use in the catheterization laboratory, “off-line”<unk><unk>  has proven invaluable for research investigation in determining the effect of new drugs and devices on lumen dimensions early and late after percutaneous coronary interventions.
Notably, for clinical decision making in intermediate lesions, neither trained visual estimates or on-line<unk><unk>  are substitutes for precise physiologic measurements of stenosis severity, such as fractional flow reserve or coronary Doppler measurements.
Quantitative coronary angiography
Coronary artery calcium scoring
Fractional flow reserve
Coronary angiography
Coronary computed tomography
Stress echocardiography
TIMI frame count 
Exercise stress testing