Imaging System And Method For The Non-Pure Positron Emission Tomography

Abstract

Disclosed is an imaging system and method for the non-pure positron emission tomography (NPET). The NPET comprises a PET subsystem to detect the annihilated photons, and a SPECT subsystem to detect the associated gamma. These two subsystems are connected by a triple coincidence circuit. The source position can be determined through detection of the three photons using the triple coincidence circuit. As long as these three photons are simultaneously detected and their energies are right, the source position is directly calculated and located on the intersection of an associated line and an annihilated line. The present invention provides good temporal resolution and quantitative analysis. It immunes to scatter and random events and achieves a high signal-to-noise ratio. Real imaging is also possible in the NPET system.

Description

FIELD OF THE INVENTION[0001]The present invention generally relates to an imaging system and method for the non-pure positron emission tomography (NPET), which may be used to determine the source position through the detection of three photons.BACKGROUND OF THE INVENTION[0002]Because of its high sensitivity and specificity for detecting a wide range of cancers in oncology, the positron emission tomography (PET) system is becoming very popular for diagnostic study. Coincident detection in the PET system provides the projection sampling which can be reconstructed to yield tomographic images. The primary advantage of PET is its ability to quantify the metabolism activity inside the body.[0003]FIG. 1 shows a conventional PET system with the coincidence circuitry. The PET system utilizes coincident detection of a pair of photons generated by the annihilation of the positron and electron. It includes hundreds of detectors arranged in a ring shape and positioned around an object being test...

AI Technical Summary

Benefits of technology

[0016]An advantage of the present invention is that source position is calculated directly from the detected three photons, without 180° data acquisition or image reconstruction. This makes real time imaging possible. The present invention also provides good temporal resolution and quantitative analysis. It immunes to scatter and random events and achieves a high signal-to-noise ratio (SNR).

[0017]The foregoing and other features, aspects and advantages of the present invention will become better understood from a careful reading of a detailed description provided herein below with appropriate reference to the accompanying drawings.

Problems solved by technology

Currently, the spatial resolution of a PET system is limited by the high 511-keV photon energy, non-colinearity of the annihilation photons, positron range, and detector technology.

The pinhole SPECT requires a heavy collimated detector to rotate around the object and a small misalignment in the setup can generate artifact.

However, the absorption of FDG is mainly due to the absorption of glucose for the metabolic process and is not organ specific.

Furthermore, the short half-life of 18F limits its usage when a long observation is needed.

This downgrades the PET performance.

Images