High-sensitivity cardiac SPECT system design with collimator-less interspaced mosaic-patterned scintillators

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Instrumentation

Background:

• Single-photon emission computed tomography (SPECT) is crucial for myocardial perfusion imaging (MPI).
• Existing cardiac SPECT systems face a resolution-sensitivity trade-off due to mechanical collimators, limiting scan speed.
• This limitation hinders the capability for rapid cardiac scans.

Purpose of the Study:

• To propose and evaluate a novel collimator-less cardiac SPECT system.
• To significantly improve SPECT system sensitivity and reduce scan times.
• To achieve this without compromising image resolution in MPI.

Main Methods:

• Development of a collimator-less SPECT system with 7 mosaic-patterned detector modules in a half-ring geometry.
• Detector modules utilize sparsely distributed GAGG(Ce) scintillators in a mosaic pattern.
• Monte Carlo simulations and prototype experiments were conducted for resolution and performance evaluation.

Main Results:

• The simulated system achieved a sensitivity of 16.31% ± 8.85% within the field-of-view.
• High-resolution phantom studies demonstrated clear separability of 6-mm rods and 5-mm disks.
• Satisfactory MPI image quality was achieved with a 30-second acquisition time in cardiac phantom studies.

Conclusions:

• The proposed collimator-less SPECT approach offers high sensitivity for medical imaging.
• This technology enables very fast cardiac scans with excellent image resolution.
• Further development is underway to create a practical 3D imaging system.