Performance of a SPECT collimator-detector response reconstruction algorithm: phantom studies and validation in...

Area of Science:

• Nuclear Medicine
• Medical Imaging
• Radiopharmaceutical Therapy

Background:

• Filtered Back Projection (FBP) is the standard for SPECT/CT image reconstruction.
• Recent advancements include corrective collimator detector response (CDR) and iterative reconstruction packages.
• Evaluating new reconstruction protocols like Evolution for Bone (EfB) is crucial for optimizing imaging.

Purpose of the Study:

• To assess the performance of the Evolution for Bone (EfB) package, a novel CDR image reconstruction tool.
• To compare EfB's resolution recovery and iterative reconstruction protocols against standard FBP.
• To evaluate the feasibility of reducing SPECT/CT acquisition time by 50% (15s/projection).

Main Methods:

• Phantom studies analyzed tomographic spatial resolution, contrast, noise, and signal-to-noise ratio (SNR).
• Patient studies involved 16 patients with suspected inflammation using [99mTc]HMPAO-labeled leukocytes for SPECT/CT.
• Target-to-background ratio (TBR), lesion boundaries, and visual inspection by blinded experts were assessed.

Main Results:

• EfB significantly improved phantom resolution and reduced noise compared to FBP, primarily due to iterative methods.
• Patient studies showed improved lesion boundary definition with iterative reconstruction; EfB enhanced TBR.
• Reduced acquisition time (15s/projection) increased noise but did not alter resolution; EfB maintained image quality.

Conclusions:

• Resolution recovery, as implemented in EfB, demonstrably improves image quality metrics including resolution, noise, SNR, and TBR.
• EfB enables a significant reduction in SPECT/CT acquisition time without compromising diagnostic image quality.
• The findings support EfB as a valuable tool for enhancing SPECT/CT imaging in inflammatory conditions.