PET Detector Depth-Dependent Reflector for TOF and DOI
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Solution Overview
Problem
Existing PET scanners face challenges in measuring both time of flight (TOF) and depth of interaction (DOI) without adding complex components or construction processes, which are costly and degrade TOF resolution due to light sharing among multiple photosensors.
Innovation Solution
A PET detector design using miniblocks with inner reflectors having depth-dependent transparency, allowing for simultaneous measurement of TOF and DOI by varying light sharing patterns within miniblocks, maintaining high TOF resolution through careful reflector shaping and light confinement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple PET detectors are used to measure both TOF and DOI, then measurement capability is improved, but device complexity and cost increase
Solution Approach 1:
The patent makes the detector block universal by enabling it to perform both TOF and DOI measurements using the same detector crystals and photosensors. The depth-dependent transparency of the reflector allows a single detector to serve multiple measurement functions, eliminating the need for separate detectors for each measurement type.
Solution Approach 2:
The patent changes the parameter of reflector transparency to be depth-dependent rather than uniform. This parameter change enables the same physical structure to provide different light transmission characteristics at different depths, allowing the detector to distinguish between TOF and DOI information without additional components.
2Adaptability or versatility
If multiple photosensors are used to measure both TOF and DOI, then measurement capability is improved, but TOF resolution deteriorates due to light sharing
Solution Approach 1:
The patent applies local quality by making the reflector transparency vary with depth rather than being uniform throughout. This creates different light sharing patterns at different depths, allowing the system to distinguish DOI information while maintaining consistent TOF measurement quality across the detector volume.
Solution Approach 2:
The depth-dependent transparent reflector acts as an intermediary element that enables DOI measurement without requiring additional photosensors. It mediates between the detector crystal and the photosensor, providing depth information through controlled light transmission while preserving the timing information needed for TOF measurement.
3Adaptability or versatility
If complex components are added to measure DOI, then measurement capability is improved, but manufacturing complexity increases
Solution Approach 1:
The patent makes the detector block universal by enabling it to perform both TOF and DOI measurements using the same detector crystals and photosensors. The depth-dependent transparency of the reflector allows a single detector to serve multiple measurement functions, eliminating the need for separate detectors for each measurement type.
Solution Approach 2:
The patent changes the parameter of reflector transparency to be depth-dependent rather than uniform. This parameter change enables the same physical structure to provide different light transmission characteristics at different depths, allowing the detector to distinguish between TOF and DOI information without additional components.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design enables improved image quality and spatial resolution in PET scanners by accurately determining DOI while preserving TOF resolution, enhancing clinical scanner performance without increasing complexity or cost.
Implementation Method 1
the inner reflector having a depth-dependent transparency, a first photosensor configured to detect light from a gamma ray detection event
Implementation Method 2
inner reflector having a depth-dependent transparency
Implementation Method 3
a plurality of detector crystals... a first photosensor configured to detect light from a gamma ray detection event
Implementation Method 4
a first photosensor configured to detect light from a gamma ray detection event, a first intensity of the light detected by the first photosensor
Data Source
AI summary
A PET apparatus includes a detector block including a miniblock including detector crystals, a first detector crystal and a second detector crystal being separated by an inner reflector, the inner reflector having a depth-dependent transparency, a first photosensor configured to detect light from a gamma ray detection event, and a second photosensor configured to detect the light from the gamma ray detection event, a first intensity and a second intensity of the light detected by the first and second photosensor being dependent on the depth-dependent transparency of the inner reflector; and processing circuitry configured to determine, based on the detected first intensity, a first energy, determine, based on the detected second intensity, a second energy, and determine, based on the first energy and the second energy, a depth of interaction (DOI) of the gamma ray detection event.