Improving SPECT MPI

Two of this month’s top stories in molecular imaging dealt with making SPECT myocardial perfusion imaging (MPI) more effective.

The first comes from Finland, where research conducted at Kuopio University Hospital focused on a novel reconstruction method that could reduce scan times by as much as 50 percent.

PhD candidate Tuija Kangasmaa, and colleagues noted that complications of motion, image noise, scatter and attenuation and collimator-detector response (CDR) can negatively impact image quality. Shorter scan times, though, could reduce artifacts.

The researchers halved acquisition time, compensating for scatter by enhancing a statistical method of analysis based on counts at acquisition known as Monte Carlo-based scatter compensation. They also combined simultaneous use of dual imaging tracers Tl-201 and Tc-99m, and made it possible for both the stress and rest scans to be performed in one session.

You can read more about the technique here.

The other top story focused on SPECT MPI looked at software designed to provide a comprehensive map of myocardial perfusion and function. This is definitely a tool to improve practice, but there’s one hitch: different software packages don’t always agree with each other.

Researchers from the University of Alabama evaluated three commercially available software packages—Quantitative Perfusion SPECT, Emory Cardiac Toolbox and 4 Dimension-Myocardial SPECT. Testing the software on 120 consecutive cardiac patients with abnormal regadenoson SPECT MPI, and found significant discordance in 62 percent of cases in terms of defining whether defects were small, moderate or large. The software packages were more consistent when it came to evaluating parameters for LV ejection fraction, volumes and mass.

As these tools continue to improve, it may be important to ensure the same software is used consistently on a given patient across imaging studies.

-Evan Godt
Editor – Health Imaging