Automatic determination of cardiovascular risk by CT attenuation correction maps in Rb-82 PET/CT

background:we investigated fully automatic coronary artery calcium (cac) scoring and cardiovascular disease (cvd) risk categorization from ct attenuation correction (ctac) acquired at rest and stress during cardiac pet/ct and compared it with manual annotations in ctac and with dedicated calcium scoring ct (csct). methods: and results:we included 133 consecutive patients undergoing myocardial perfusion 82rb pet/ct with the acquisition of low-dose ctac at rest and stress. additionally, a dedicated csct was performed for all patients. manual cac annotations in ctac and csct provided the reference standard. in ctac, cac was scored automatically using a previously developed machine learning algorithm. patients were assigned to a cvd risk category based on their agatston score (0, 1-10, 11-100, 101-400, >400). agreement in cvd risk categorization between manual and automatic scoring in ctac at rest and stress resulted in cohen’s linearly weighted κ of 0.85 and 0.89, respectively. the agreement between csct and ctac at rest resulted in κ of 0.82 and 0.74, using manual and automatic scoring, respectively. for ctac at stress, these were 0.79 and 0.70, respectively. conclusion:automatic cac scoring from ctac pet/ct may allow routine cvd risk assessment from the ctac component of pet/ct without any additional radiation dose or scan time.