- conditions which would make MDCT coronary angiography/ cardiac FDG-PET protocol unsafe or unfeasible including: significant renal dysfunction with an eGFR by Cockcroft-Gault equation of <60 ml/min, contrast dye allergy, contraindication to beta-blockers (e.g. severe asthma, hypotension, or heart block), or contraindication to nitroglycerin (uninterruptable administration of phosphodiesterase inhibitors), body weight greater than 320 lbs (PET scanner table limitation)