Characterization of point-spread function specification error on Geometric Transfer Matrix partial volume correction...

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Neuroscience

Background:

• Positron Emission Tomography (PET) quantitation is affected by partial-volume effects.
• Partial-volume correction (PVC) methods, such as the Geometric Transfer Matrix (GTM), aim to mitigate these effects.
• Accurate scanner point-spread function (PSF) characterization is crucial for reliable GTM PVC.

Purpose of the Study:

• To evaluate the impact of PSF misspecification on GTM-based PVC in amyloid PET imaging.
• To assess the influence of these errors on amyloid status classification.

Main Methods:

• Analyzed 29 subjects with [11C]PiB PET and MRI scans.
• Used FreeSurfer for region-of-interest (ROI) parcellation.
• Performed GTM PVC with standard and varied PSF parameters (full-width at half-maximum, w).
• Calculated standardized uptake value ratios (SUVRs) and analyzed GTM operating-point characteristics.

Main Results:

• Minor errors (approx. 1 mm) in PSF specification led to modest SUVR errors (few percent).
• The anterior ventral striatum showed higher sensitivity to PSF errors (up to 0.29 fractional error per mm).

Conclusions:

• Unavoidable inaccuracies in PSF specification for GTM PVC do not necessarily preclude its use in amyloid quantitation.
• Reasonable caution in PSF parameterization is advised for reliable results.