Gamma Radiation Imaging System via Variable and Time-Multiplexed Pinhole Arrays.

Ariel Schwarz,Amir Shemer,Rachel Bar-Shalom,Yossef Danan,Hemy Avraham,Alex Zlotnik,Zeev Zalevsky

doi:10.3390/s20113013

Abstract

Biomedical planar imaging using gamma radiation is a very important screening tool for medical diagnostics. Since lens imaging is not available in gamma imaging, the current methods use lead collimator or pinhole techniques to perform imaging. However, due to ineffective utilization of the gamma radiation emitted from the patient’s body and the radioactive dose limit in patients, poor image signal to noise ratio (SNR) and long image capturing time are evident. Furthermore, the resolution is related to the pinhole diameter, thus there is a tradeoff between SNR and resolution. Our objectives are to reduce the radioactive dose given to the patient and to preserve or improve SNR, resolution and capturing time while incorporating three-dimensional capabilities in existing gamma imaging systems. The proposed imaging system is based on super-resolved time-multiplexing methods using both variable and moving pinhole arrays. Simulations were performed both in MATLAB and GEANT4, and gamma single photon emission computed tomography (SPECT) experiments were conducted to support theory and simulations. The proposed method is able to reduce the radioactive dose and image capturing time and to improve SNR and resolution. The results and method enhance the gamma imaging capabilities that exist in current systems, while providing three-dimensional data on the object.

Highlights

In the field of human clinical radionuclide imaging two major techniques are used
The overall outcome is still better than the results of the one pinhole system
The stage involved experimental validation performed with a gamma radiation system that was available in the General Electric Healthcare laboratories in Haifa, Israel and in the Nuclear

Summary

Introduction

In the field of human clinical radionuclide imaging two major techniques are used These techniques are known as single photon emission computed tomography (SPECT) and positron emission tomography (PET). Those techniques are invaluable especially for highly sensitive molecular imaging in the study of human diseases, the testing of new pharmaceuticals, the development of new imaging tracers and the understanding of biological mechanisms. A gamma camera detector can determine the presence and position of an incident gamma photon, but obtains no information about the incidence direction For this reason, in the SPECT technique system, a parallel hole collimator is positioned between the object and the gamma camera detector and so, only photons, which originate from specific directions, can continue on their path to the crystal detector.

Objectives

Results

Conclusion