Performances diagnostiques des tomoscintigraphies myocardiques de stress, réalisées avec une caméra à semi-conducteurs et un protocole très faible dose

Abstract

IntroductionThis retrospective study aimed to assess the performances in the detection of coronary artery disease patients of the stress myocardial perfusion imaging (MPI) performed with a semiconductor camera, a very low dose stress-rest protocol and short recording times. Material and methodsWe analyzed consecutive MPI exams, which has been routinely planed with the “D-SPECT” semiconductor camera, a 1-day stress-rest protocol, very low doses of Sestamibi-99mTc (120MBq at stress and 360MBq at rest for a 75kg body weight patient) and short acquisition-times targeting the recording of 500 myocardial kcounts (on average, 8min for stress and 3min for rest). The ability to detect coronary artery stenosis (>50% diameter reduction) was assessed in a group of 118 patients, who had coronary angiography at ≤3months from MPI, and normalcy rate was assessed in a group of 74 patients showing a low pretest probability of coronary artery disease (<10%). ResultsSensitivity, positive predictive value and global accuracy for identifying the 81 patients with ≥1 coronary artery stenosis were 85%, 83% and 78%, respectively; and normalcy rate was 96%. Mean effective doses were: (1) 4.9±1.4mSv in the group with coronary angiography and where most exams (90%) comprised both stress and rest MPI; and (2) 1.9±1.5mSv in the low probability group and where most exams (70%) comprised only stress MPI. ConclusionWhen performed with a sensitive semiconductor camera and a very low dose stress-rest protocol, MPI provides high diagnostic performances, equivalent to those documented with conventional cameras in the same study setting, but with dramatic reduction of patients’ radiation.