Value of attenuation correction in stress-only myocardial perfusion imaging using CZT-SPECT

Attenuation correction (ac) improves the diagnostic outcome of stress-only myocardial perfusion imaging (mpi) using conventional spect. our aim was to determine the value of ac using a cadmium zinc telluride-based (czt)-spect camera. we retrospectively included 107 consecutive patients who underwent stress-optional rest mpi czt-spect/ct. next, we created three types of images for each patient; (1) only displaying reconstructed data without the ct-based ac (nc), (2) only displaying ac, and (3) with both nc and ac (nc + ac). next, two experienced physicians visually interpreted these 321 randomized images as normal, equivocal, or abnormal. image outcome was compared with all hard events over a mean follow-up time of 47.7 ± 9.8 months. the percentage of images interpreted as normal increased from 45% using the nc images to 72% using ac and to 67% using nc + ac images (p < .001). hard event hazard ratios for images interpreted as normal were not different between using nc and ac (1.01, p = .99), or nc and nc + ac images (0.97, p = .97). ac lowers the need for additional rest imaging in stress-first mpi using czt-spect, while long-term patient outcome remained identical. use of ac reduces the need for additional rest imaging, decreasing the mean effective dose by up to 1.2 msv.