Performance evaluation of a novel multi-pinhole collimator for dopamine transporter SPECT

Area of Science:

• Nuclear Medicine
• Medical Imaging Physics

Background:

• Conventional Single-Photon Emission Computed Tomography (SPECT) systems face a resolution-sensitivity tradeoff.
• Multi-pinhole (MPH) collimators offer a potential solution for improved resolution and sensitivity in SPECT, particularly for small organs.

Purpose of the Study:

• To evaluate a novel triple-head MPH collimator system designed for dopamine transporter (DAT) SPECT.
• To assess the impact of MPH collimators on count sensitivity, spatial resolution, and contrast recovery compared to conventional collimators.

Main Methods:

• Count sensitivity was measured using a 99mTc point source. Spatial resolution was assessed with a Derenzo phantom. Contrast recovery was evaluated using an anthropomorphic striatum phantom.
• Scans were performed with a triple-head MPH system and compared to double-head fan-beam and LEHRHS collimators.
• A patient scan was conducted with both LEHRHS and MPH collimators for direct comparison.

Main Results:

• The triple-head MPH system demonstrated significantly higher peak sensitivity (620 cps/MBq) compared to fan-beam (225 cps/MBq).
• MPH SPECT clearly visualized rods ≥ 5 mm in the Derenzo phantom and improved striatal contrast recovery by ≥ 20% over fan-beam SPECT.
• Patient scans showed excellent image quality with near PET-like delineation of the putamen and caudate nucleus using MPH collimators.

Conclusions:

• Dedicated MPH collimators substantially improve the resolution-sensitivity tradeoff in DAT SPECT.
• MPH SPECT offers superior performance compared to fan-beam and LEHRHS collimators for DAT imaging.
• This technology holds promise for enhanced diagnostic accuracy in conditions like Parkinson's disease.