3D Cavity Detector Array for CT Resolution and Dose Tradeoff
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Solution Overview
Problem
High-resolution and low-dose imaging in computed tomography (CT) scanners face a tradeoff between detection efficiency and resolution, as increasing resolution decreases geometric efficiency due to reduced active detector areas.
Innovation Solution
A detector array with three-dimensional cavities containing multiple photosensitive sub-pixels and a scintillator, where the scintillator's sub-portions are both inside and outside the cavity, allowing for increased resolution and spectral imaging while maintaining detection efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the active area of individual detector pixels is decreased to increase resolution, then the resolution is improved, but the geometric efficiency decreases
Solution Approach 1:
The invention transitions from a two-dimensional detector surface to a three-dimensional cavity structure. The cavity extends in the depth dimension (z-axis) to accommodate the scintillator, allowing the detector to collect light photons from multiple depths while maintaining a compact footprint. This dimensional transition enables increased resolution without proportionally reducing the active area.
Solution Approach 2:
The scintillator is nested within the cavity structure, with the cavity acting as a container that holds the scintillator material in close proximity to the photosensitive regions. This nesting arrangement maximizes the interaction between x-rays and the scintillator while ensuring efficient light collection by the photosensitive regions, thereby maintaining geometric efficiency despite reduced pixel dimensions.
2Measurement precision
If the active area of individual detector pixels is decreased to increase resolution, then the resolution is improved, but the dose required for imaging increases
Solution Approach 1:
The cavity structure serves multiple functions simultaneously: it houses the scintillator, guides light photons to the photosensitive regions, and provides structural support. This self-service design eliminates the need for additional components that would increase complexity and dose requirements, as the cavity itself performs the light guidance function that would otherwise require separate optical elements.
Solution Approach 2:
By utilizing the third dimension (depth) for scintillator placement and light collection, the system achieves better signal-to-noise ratio and detection efficiency without increasing the lateral dimensions. This allows for reduced pixel size and improved resolution while maintaining adequate light collection efficiency, thereby reducing the required imaging dose.
3Measurement precision
If multiple photosensitive regions are placed on the cavity surface to increase resolution, then the resolution is improved, but the device complexity increases
Solution Approach 1:
The cavity structure performs multiple functions: it contains the scintillator, guides light photons to the photosensitive regions, and provides structural support. This multi-functionality reduces the need for additional components, thereby limiting the increase in device complexity despite the presence of multiple photosensitive regions on the cavity surface.
Solution Approach 2:
The detector is segmented into distinct functional regions: the cavity structure, the scintillator, and the photosensitive regions. This segmentation allows for modular design and manufacturing, where each component can be optimized independently. The cavity with its integrated scintillator and multiple photosensitive regions can be manufactured as a single module, reducing assembly complexity.
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
This configuration enhances resolution and light collection efficiency, reducing the dose required for imaging while allowing for spectral imaging capabilities.
Implementation Method 1
A scintillator, including a first sub-portion that is located in the cavity and which emits the light photons in response to absorbing x-ray photons
Implementation Method 2
at least two photosensitive regions and a non-photosensitive region there between, defining at least two sub-pixels which detect light photons traversing within the three dimensional cavity and produce respective signals indicative thereof
Data Source
Figure 1
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AI summary
A detector array (112) includes at least one detector pixel (306) with a cavity (400) that defines a three dimensional volume. A surface of the cavity includes at least two photosensitive regions and a non-photosensitive region there between, defining at least two sub-pixels (306i, 3062) which detect light photons traversing within the three dimensional cavity and produce respective signals indicative thereof. The detector array further includes a scintillator (302), including a first sub-portion that is located in the cavity and which emits the light photons in response to absorbing x-ray photons. Light photons emitted by the first sub-portion are detected by both of the at least two sub-pixels