Improving multi-pinhole CZT myocardial perfusion imaging specificity without changing sensibility by using adapted...

Area of Science:

• Nuclear Cardiology
• Medical Imaging
• Cardiovascular Disease Diagnosis

Background:

• Meta-analyses indicate cardiac multi-pinhole cadmium-zinc-telluride myocardial perfusion imaging (MPI) has a sensitivity of ~0.9 and specificity of ~0.7.
• Artifacts in MPI can reduce diagnostic accuracy, necessitating improved imaging techniques.
• Current single photon emission computed tomography (SPECT) protocols may benefit from optimization to enhance specificity.

Purpose of the Study:

• To investigate a simple method for reducing artifacts in MPI using SPECT.
• To enhance the specificity of myocardial SPECT without negatively impacting its sensitivity.

Main Methods:

• Two hundred patients undergoing [99mTc]Tc-tetrofosmin SPECT were prospectively enrolled (100 with ischemia/necrosis, 100 with reversible SPECT artifacts).
• Two image reconstruction methods were compared: original (Butterworth pre/post-filter, 37% Nyquist cutoff, order 7) and modified (25% Nyquist cutoff, order 5).
• Sum stress or rest scores (SSRS) were calculated for each reconstruction to assess image quality and artifact reduction.

Main Results:

• No significant difference in SSRS was found between reconstructions in patients without artifacts (p=0.54).
• A significant difference in SSRS was observed in patients with artifacts (p<0.0001), with the modified reconstruction showing a substantial improvement (69.7% ± 16.2% relative difference).
• The modified Butterworth filter settings effectively reduced artifacts in myocardial SPECT.

Conclusions:

• Employing a Butterworth prefilter and post-filter with a 25% Nyquist frequency cutoff before iterative reconstruction reduces artifacts in myocardial SPECT.
• This optimized image processing enhances myocardial SPECT specificity without compromising sensitivity.
• The findings suggest a simple, effective method to improve diagnostic performance in myocardial perfusion imaging.