Table 4: Mean radiation exposure in millisieverts (mSv) from the index SPECT myocardial perfusion imaging (MPI) study is listed for both cohorts. The total annual exposure to iatrogenic radiation is calculated by including radiation from subsequent MPI studies and invasive coronary angiography (ICA) procedures. Standard deviation is listed in parentheses.

SPECT (n = 277) SPECT-CT (n = 273)
Radiation from SPECT MPI 13.2 (3.2) 11.0 (2.1) p < 0.001
Radiation from SPECT MPI and ICA within one year 18.0 (18) 14.5 (18) p = 0.02