May 18th, 2011
New Technique Cuts Radiation Dose of MPI SPECT by Half
A new study raises the possibility that the radiation dose for MPI SPECT imaging can be reduced by half without sacrificing image quality, according to Dr. Nili Zafrir, who presented the results of the study this week at the International Conference of Non-Invasive Cardiovascular Imaging in Amsterdam.
Recently, software has become available that can reduce the image acquisition time of MPI SPECT. Zafrir and her colleagues in Israel sought to test the hypothesis that the same software could be used to reduce the radiation dose of Tc sestamibi by half. Some 218 patients were randomized to either a “half-dose” protocol using the “half time” software or a “full-dose” protocol using standard software techniques.
The investigators reported that 95% of images in both the half-dose group and the full-dose group were rated excellent to good. The effective dose was 7.2 mSv in the half-dose group compared with 13 mSv in the full-dose group, a highly significant difference (p<0.0001). They further reported that slightly more than a third of patients in the half-dose group had a “stress only” study and received a very low radiation dose of only 2 mSv.
“Clearly, we cannot be certain what the long-term benefit of reducing radiation exposure might be, but theoretically it would seem important,” said Dr. Zafrir, in an ESC press release.