Influence of Rotation Increments on Imaging Performance for a Rotatory Dual-Head PET System

الملخص EN

For a rotatory dual-head positron emission tomography (PET) system, how to determine the rotation increments is an open problem.

In this study, we simulated the characteristics of a rotatory dual-head PET system.

The influences of different rotation increments were compared and analyzed.

Based on this simulation, the imaging performance of a prototype system was verified.

A reconstruction flowchart was proposed based on a precalculated system response matrix (SRM).

The SRM made the relationships between the voxels and lines of response (LORs) fixed; therefore, we added the interpolation method into the flowchart.

Five metrics, including spatial resolution, normalized mean squared error (NMSE), peak signal-to-noise ratio (PSNR), contrast-to-noise (CNR), and structure similarity (SSIM), were applied to assess the reconstructed image quality.

The results indicated that the 60° rotation increments with the bilinear interpolation had advantages in resolution, PSNR, NMSE, and SSIM.

In terms of CNR, the 90° rotation increments were better than other increments.

In addition, the reconstructed images of 90° rotation increments were also flatter than that of 60° increments.

Therefore, both the 60° and 90° rotation increments could be used in the real experiments, and which one to choose may depend on the application requirement.