Summary:
UCLA researchers in the Department of Radiological Sciences have developed a novel method for coincidence counting to reduce the noise inherent in photon counting detectors.
Background:
The computed tomography (CT) scanning market is projected to grow from ~$6 billion to over $10 billion in 2030. Approximately 10% of this market size is the cost of the x-ray detector. Photon counting detectors (PCDs) are poised to play a critical role as components of next-generation CT technologies and are expected to eventually displace conventional energy-integrating detectors, starting from the premium segment. PCDs offer several advantages over energy-integrating detectors and they can provide multi-material and spectroscopic imaging while offering superior spatial resolution. In addition, PCDs improve contrast and are less susceptible to electronic noise. However, limitations to real PCD systems persist. Primarily, when employing secondary methods to increase the number of photons measured, single high-energy photons can be read as multiple events; this charge sharing limits the speed and resolution of next generation scanners. Several attempts have been made to mitigate charge sharing, but most existing proposals exacerbate pulse pileup, another detector non-ideality, and are hence not suited for PCDs today.
Innovation:
UCLA researchers have developed a method for charge sharing compensation called a coincidence counting bin (CCB) that can correct for charge sharing in the detector circuitry without compromise to resolution or pulse pileup and by using fast digital logic. This method stands to drastically decrease the noise experienced during x-ray CT scans. The proposed CCB improves spectral dose efficiency by 50-80%. Compared to other charge sharing compensation schemes, the CCB is straightforward to implement.
Patent:
17/602,962
Potential Applications:
• Spectral CT
• Digital X-rays
• Non-destructive inspection
Advantages:
• Improved spectral measurements
• Ease of implementation
• Non disruptive to existing counters
• Improved dose efficiency (50-80%)
State of Development:
The inventors have developed a prototype of the counting bin and demonstrated statistically the improvement over current gold standard methods. An article describing the technology has been published in a peer reviewed journal article.
Related Publications:
Hsieh, Scott S. "Coincidence counters for charge sharing compensation in spectroscopic photon counting detectors." IEEE transactions on medical imaging 39, no. 3 (2019): 678-687. https://ieeexplore.ieee.org/document/8792204
Reference:
UCLA Case No. 2019-543
Lead Inventor:
Scott Hsieh, UCLA Professor of Radiological Sciences (Now at Mayo Clinic Rochester, Minnesota)