[Fast myocardial perfusion imaging of stress--first protocol using CZT-technology: a preliminary report of the correlation to invasive coronary angiography].

Background: Myocardial perfusion imaging (MPI) is valuable for diagnosing coronary disease and assessing the risk of cardiac events. New technology based on semiconductors (Cadmium zinc telluride-CZT) enables reducing imaging time and improving image quality.

Methods: We retrospectively identified 57 patients who underwent MPI at Assuta using a CZT camera and invasive coronary angiography (ICA) within 60 days following nuclear testing without an intervening cardiac event, and without history of coronary disease. In addition, 25 patients with low pretest likelihood who did not undergo ICA were included in the study. All 82 patients underwent fast-acquisition, stress-first Tc-99m sestamibi MPI using very short imaging time (stress: 5:00 min., prone: 3:40 min. and rest: 2:00 min]. A low-dose stress injection (9-12 mCi, ≤ 3.5 mSv) and high rest-dose (25-32 mCi) with adjustment to patient weight were administered. Semi-quantitative visual analysis utilized a 17-segment model, 0-4 scale (0 = normal uptake, 4 = absent uptake). The summed stress score (SSS) representing stress perfusion abnormality was converted to a percentage of abnormal myocardium (SSS% = SSS/68*100). ICA served as a gold standard for the nuclear perfusion findings.

Results: The mean age was 60.1 ± 11 years and most subjects were men (58, 70.7%). Compared to low-risk patients, patients who underwent ICAwere older, and had a higher frequency of hypertension, diabetes mellitus and dyslipidemia. A low-dose stress-only test with low radiation exposure ≤ 3.5 mSv) was frequent among low-risk patients (18/25-72%). ROC analysis for identification of angiographic coronary disease by SSS% demonstrated area under curve of 0.923, 95% confidence interval 0.859-0.988, p < 0.001. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were: 91.4%, 81.2%, 78.3%, 97.2% and 86.6%, respectively.

Conclusion: Fast, low-dose stress MPI using CZT technology enables semi-quantitative analysis with high diagnostic value for coronary disease.