Two-Half PET Scanner Geometry for Organ-Specific Imaging
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Solution Overview
Problem
Conventional PET scanner designs are costly and inflexible, with cylindrical geometry optimizing for general body imaging but not allowing for specific organ or region optimization, leading to inefficiencies in detector material usage and reduced sensitivity for larger diameters or axial extents.
Innovation Solution
The introduction of a two-half PET scanner geometry, where one detector portion is arranged circumferentially around the patient with a larger axial extent and the second portion has a smaller radius, allowing for reduced detector material usage while maintaining sensitivity by optimizing the detector arrangement based on the region of interest, incorporating different detector elements and configurations for improved timing and energy resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a full-ring cylindrical PET scanner geometry is used, then general body imaging is optimized, but detector material usage becomes inefficient and sensitivity decreases for larger diameters or axial extents
Solution Approach 1:
The patent divides the traditional full-ring cylindrical detector into multiple discrete detector blocks positioned at specific locations. Instead of using a continuous ring of detectors, the invention employs segmented detector elements strategically placed to optimize imaging of specific organs or regions, thereby reducing overall detector material while maintaining or improving imaging performance for targeted applications.
Solution Approach 2:
The patent implements non-uniform detector positioning and varying detector element characteristics across different locations. Detector blocks are positioned with different axial extents and angular orientations tailored to specific imaging needs, allowing optimal sensitivity for particular organs (e.g., heart, brain, lungs) rather than uniform coverage, thus improving local imaging quality while reducing global material usage.
2Reliability
If a full-ring cylindrical PET scanner geometry is used, then general body imaging is optimized, but imaging flexibility for specific organs or regions is reduced
Solution Approach 1:
The patent employs movable and reconfigurable detector blocks that can be dynamically positioned and adjusted during scanning. The detector assembly includes mechanical components allowing rotation, translation, and reconfiguration of detector elements to adapt to different imaging scenarios, enabling the same system to optimize for various organs (heart, brain, lungs, etc.) without requiring multiple fixed systems.
Solution Approach 2:
The patent designs a multi-functional detector system where the same detector blocks can serve multiple imaging purposes by reconfiguring their positions and orientations. The system can adapt to image different organ systems (cardiac, neurological, pulmonary) using the same physical hardware, achieving versatility without requiring separate specialized systems for each application.
3Reliability
If detector axial extent is increased to improve sensitivity, then sensitivity increases, but detector cost increases by up to 50%
Solution Approach 1:
The patent applies partial action by using detector blocks with axial extents that are optimized for specific imaging needs rather than uniformly maximizing coverage. Detector elements are positioned to provide sufficient sensitivity for targeted organs without extending axially beyond what is necessary, avoiding the 50% cost increase associated with full maximum-coverage designs while maintaining adequate sensitivity for clinical applications.
Solution Approach 2:
The patent varies key detector parameters including axial extent, angular orientation, and positioning distances for different detector blocks. By optimizing these parameters specifically for each imaging application (e.g., shorter axial extent for brain imaging, different angles for cardiac imaging), the system achieves high sensitivity without requiring uniformly large detector dimensions that would drive up costs across the entire system.
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 design achieves up to 50% savings in detector cost, increased sensitivity, and improved spatial resolution, enabling efficient imaging of specific organs or regions with reduced claustrophobic stress for patients, while maintaining equivalent imaging time and quality compared to full-ring geometries.
Implementation Method 1
a positron emitter attached to the radiopharmaceutical agent will emit positrons according to the physical properties of the isotope
Implementation Method 2
when an emitted positron collides with an electron, an annihilation event occurs, wherein the positron and electron are destroyed. Most of the time, an annihilation event produces two gamma rays at 511 keV
Implementation Method 3
the location of the two scintillation events
Data Source
AI summary
An imaging system, including (1) a CT scanner configured to scan an object arranged on a patient pallet; (2) a PET scanner, including a first detector portion, including first detector elements, arranged circumferentially around the patient pallet, the first detector portion having a predetermined axial extent and transaxially subtending less than 360 degrees with respect to a central axis of the scanner; and a second detector portion, including second detector elements, arranged separately from and opposing the first detector portion, wherein the second detector elements are of a different type than the first detector elements, and the second detector portion is configured to be movable radially and circumferentially around the object; and (3) an acquisition subsystem configured to acquire first event data from the first detector portion and to acquire second event data from the second detector portion.