Development of a versatile image quality test phantom for single photon emission computed tomography system

Area of Science:

• Nuclear Medicine Imaging
• Medical Physics
• Radiological Sciences

Background:

• Periodic quality assurance (QA) is crucial for accurate Single Photon Emission Computed Tomography (SPECT) imaging.
• High costs of commercial phantoms limit accessibility, especially in resource-constrained settings.
• A need exists for affordable, versatile QA tools for SPECT systems.

Purpose of the Study:

• To develop and validate a cost-effective, modular SPECT phantom for comprehensive quality assurance.
• To assess key SPECT imaging parameters including tomographic resolution, uniformity, contrast, and slice thickness.
• To provide an accessible QA solution for nuclear medicine facilities.

Main Methods:

• A modular phantom constructed from Polymethyl methacrylate (PMMA) was designed with interchangeable modules.
• The phantom was validated using Technetium-99m (^99mTc) and a GE Healthcare Discovery 670 DR SPECT/CT scanner with LEHR collimators.
• Imaging data were analyzed for pixel size, tomographic resolution (OSEM and FBP), uniformity, contrast, and slice thickness.

Main Results:

• The developed phantom accurately measured SPECT imaging parameters, with results comparable to the commercial Jaszczak phantom.
• Tomographic resolution achieved a horizontal FWHM of 13.12 mm using OSEM, outperforming FBP.
• Tomographic uniformity was within 3.6% contrast variation, meeting IAEA standards, and small structures (rods down to 6.5 mm, spheres down to 9 mm) were detectable.

Conclusions:

• The developed modular SPECT phantom is a suitable, cost-effective tool for comprehensive periodic quality assurance in nuclear medicine.
• Its versatile design allows for future modifications and additions, enhancing its long-term utility.
• This phantom addresses the accessibility gap for essential QA in SPECT imaging, particularly in resource-limited environments.