Stress-only imaging in patients with prior SPECT MPI: a simulation study

Area of Science:

• Cardiology
• Nuclear Medicine
• Radiology

Background:

• Current guidelines recommend both stress and rest imaging for SPECT MPI.
• Stress-only imaging is feasible for low-risk patients but unstudied in high-risk populations.

Purpose of the Study:

• To determine if omitting the repeat resting scan impacts the interpretation of stress tests in patients with prior SPECT MPI.
• To evaluate the feasibility of stress-only SPECT MPI in patients with prior imaging.

Main Methods:

• Retrospective analysis of 47 MPI studies with prior images.
• Two blinded readers compared interpretations of stress-only SPECT vs. conventional rest-stress SPECT.
• Primary endpoint: comparison of summed difference scores (SDS) between stress-only and rest-stress interpretations.

Main Results:

• 36% of patients had prior SPECT MPI; 48% were eligible for stress-only imaging.
• Strong agreement (r = 0.866) between SDS from stress-only (vs. old rest) and rest-stress (vs. new rest) interpretations.
• 87% of eligible studies could use stress-only SPECT MPI, reducing radiation by 76%.

Conclusions:

• Stress-only imaging yields similar data to conventional rest-stress imaging in patients with prior resting studies.
• Stress-only SPECT MPI may be expanded to previously studied or higher-risk populations.
• A resting study can be added if stress-only interpretation is unclear.