Optimization of ^99m Tc whole-body SPECT/CT image quality: A phantom study.

Area of Science:

• Medical Imaging
• Nuclear Medicine

Background:

• Single-photon emission computed tomography/computed tomography (SPECT/CT) is crucial for diagnosing various conditions.
• Optimizing acquisition and reconstruction protocols is essential for improving efficiency and maintaining diagnostic accuracy.

Purpose of the Study:

• To determine the shortest possible acquisition time for clinical whole-body SPECT/CT (WB-SPECT/CT) while preserving image quality.
• To investigate the impact of acquisition time and reconstruction parameters on SPECT/CT image quality.

Main Methods:

• Used a NEMA International Electrotechnical Commission (IEC) phantom with ^99m Tc.
• Simulated acquisition times of 15, 8, and 3 seconds per projection angle.
• Reconstructed images using 3D ordered subset expectation maximization (OSEM) with varying iterations and post-smoothing filters.

Main Results:

• Optimal reconstruction parameters (12 iterations, 8 subsets, 8 mm Gaussian filter) were identified.
• An acquisition time of 8 seconds per projection angle achieved a contrast-to-noise ratio >5 for small spheres.
• Reduced acquisition time was achieved without compromising image quality.

Conclusions:

• Optimized reconstruction parameters successfully preserved image quality with reduced acquisition time.
• An optimal protocol for clinical ^99m Tc SPECT/CT involves 8 seconds per projection angle, 12 iterations, 8 subsets of 3D OSEM, and an 8 mm Gaussian post-filter.