Evaluation of imaging protocol for ECT based on CS image reconstruction algorithm

TL;DR

This paper evaluates imaging protocols for ECT, demonstrating that acquisition counts are more critical than sampling angles, and introduces a compressed sensing-based iterative reconstruction algorithm that reduces radiopharmaceutical dose while maintaining image quality.

Contribution

The study develops a novel iterative reconstruction algorithm based on compressed sensing for limited-view, low-dose ECT imaging, improving image quality with reduced radiopharmaceutical dose.

Findings

Acquisition counts impact image quality more than sampling angles.

The new algorithm achieves comparable or better image quality with half the dose.

Limited-view reconstruction artifacts are reduced using total variation regularization.

Abstract

SPECT (Single-photon Emission Computerized Tomography) and PET (Positron Emission Tomography) are essential medical imaging tools, for which the sampling angle number, scan time should be chosen carefully to compromise between image quality and the radiopharmaceutical dose. In this study, the image quality of different acquisition protocol was evaluated via varied angle number and count number per angle with Monte Carlo simulation data. It was shown that when similar imaging counts were used, the factor of acquisition counts was more important than that of the sampling number in ECT (Emission Computerized Tomography). To further reduce the activity requirement and the scan duration, an iterative image reconstruction algorithm for limited-view and low-dose tomography based on compressed sensing theory has been developed. The total variation regulation was added in the reconstruction process to improve SNR (Signal to Noise Ratio) and reduce the artifacts caused by the limited angle sampling. Maximization of maximum likelihood of the estimated image and the measured data and minimization of the total variation of the image are alternative implemented. By using this advanced algorithm, the reconstruction process is able to achieve image quality matching or exceeding that of normal scan with only half of the injection radiopharmaceutical dose.