The Particulars: The American Society of Nuclear Cardiology (ASNC) has issued a goal of reducing radiation doses to 9 mSv or lower in 50% of myocardial perfusion imaging (MPI) studies by 2014. To achieve this goal, other approaches may be beneficial. Use of a low-dose stress first, high-dose rest second (stress/rest)—as opposed to rest first, stress second (rest/stress)—single positron emission computed tomography (SPECT) MPI protocol may help achieve this goal. This approach could limit radiation doses by identifying patients with normal reads who would need only lose-dose stress imaging.

Data Breakdown: Outpatients, inpatients, and ED patients at high risk for cardiac problems participated in a study and underwent stress/rest, rest/stress, or stress-only imaging. The typical radiation dose for stress-only imaging was 2 mSv, compared with 9 mSv for both stress/rest and rest/stress imaging approaches.

Take Home Pearls: Use of a stress/rest SPECT MPI protocol appears to be feasible and may exceed the ASNC’s goal of reducing radiation doses to 9 mSv or lower in 50% of patients by 2014. With this protocol, patients with normal reads on low-dose stress imaging may be able to avoid high-dose rest imaging.