ness ▁of ▁breath ▁of ▁a ▁possible ▁card iac ▁origin . ▁ ▁Rad iation ▁do se ▁ ▁From ▁ 1 9 9 3 ▁to ▁ 2 0 0 1 , ▁my oc ard ial ▁perf usion ▁sc ans ▁in ▁the ▁US ▁increased ▁> 6 % / y ▁with ▁" no ▁just ification ". ▁My oc ard ial ▁perf usion ▁imag ing ▁sc ans ▁are ▁" power ful ▁predict ors ▁of ▁future ▁clin ical ▁events ", ▁and ▁in ▁theory ▁may ▁identify ▁patients ▁for ▁whom ▁ag gress ive ▁ther ap ies ▁should ▁improve ▁outcome . ▁But ▁this ▁is ▁" only ▁a ▁hypothesis , ▁not ▁a ▁proof ". ▁However , ▁several ▁tri als ▁have ▁indicated ▁the ▁high ▁sens itivity ▁( 9 0 %) ▁of ▁the ▁test , ▁regardless ▁of ▁trac er , ▁out we igh ing ▁any ▁potential ▁det r iment al ▁effect ▁of ▁the ▁ion ising ▁radiation . ▁In ▁the ▁UK , ▁N ICE ▁guidance ▁recomm ends ▁my oc ard ial ▁perf usion ▁sc ans ▁following ▁my oc ard ial ▁inf ar ction ▁or ▁re per f usion ▁inter vent ions . ▁The ▁power ▁of ▁pro gn osis ▁from ▁a ▁my oc ard ial ▁perf usion ▁scan ▁is ▁excellent ▁and ▁has ▁been ▁well ▁tested , ▁and ▁this ▁is ▁" per haps ▁the ▁area ▁of ▁nuclear ▁card i ology ▁where ▁the ▁evidence ▁is ▁most ▁strong ". ▁ ▁Many ▁rad ion u cl ides ▁used ▁for ▁my oc ard ial ▁perf usion ▁imag ing , ▁including ▁rub id ium - 8 2 , ▁te ch net ium -