PET Apparatus Body Movement Detection Using Annihilation Coordinates
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Solution Overview
Problem
Current positron emission computed tomography (PET) systems require external devices for respiration-synchronized imaging, which are cumbersome and prone to misalignment, complicating the imaging process.
Innovation Solution
The PET apparatus directly processes detection data to obtain body movement information using time-of-flight (TOF) information from coincidence counting data, eliminating the need for external devices by calculating annihilation coordinates and detecting temporal changes in body movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an external respiratory displacement monitor and infrared light reflection marker are used to obtain body movement information, then respiration-synchronized imaging can be performed, but the device complexity and ease of operation deteriorate due to separate setup and adjustment requirements
Solution Approach 1:
The patent merges the body movement detection function into the PET apparatus itself by using the existing detector to capture annihilation gamma-rays and calculate body movement information from the detection data. This eliminates the need for separate external respiratory displacement monitors and infrared markers, integrating multiple functions into a single system while maintaining respiration-synchronized imaging capability
Solution Approach 2:
The PET detector is made multi-functional by enabling it to perform both its primary function of detecting annihilation gamma-rays for image reconstruction and a secondary function of detecting body movement information. By analyzing the temporal changes in detection data, the same detector system provides both imaging and motion tracking capabilities, reducing the need for specialized external devices
2Measurement precision
If an infrared light reflection marker is placed on the subject's chest region, then body movement information can be obtained, but the ease of operation deteriorates due to potential misalignment or marker displacement during imaging
Solution Approach 1:
The system uses the subject's own annihilation gamma-ray emissions as the signal source for body movement detection, eliminating the need for external markers. The detection data from the PET scanner itself provides the necessary information to track body movement, making the system self-sufficient and removing the operational burden of marker placement and maintenance
Solution Approach 2:
The patent uses the annihilation gamma-rays as an intermediary signal that naturally carries body movement information. Instead of requiring direct observation of external markers, the system detects changes in the gamma-ray detection patterns caused by body movement, using the radiation itself as a mediator to convey positional information
3Measurement precision
If external devices are used for body movement detection, then body movement information can be obtained, but the device complexity increases and the imaging process becomes more complicated
Solution Approach 1:
The patent combines body movement detection with the PET imaging process by utilizing the same detector and data acquisition system. The body movement information is extracted from the existing detection data through calculation of annihilation coordinates and analysis of temporal changes, merging two measurement functions into a single integrated process without requiring separate imaging procedures
Data Source
AI summary
A positron emission computed tomography apparatus according to an embodiment includes a detector, a coincidence counting information generating unit, and a body movement detecting unit. The detector detects annihilation radiation released from a subject. The coincidence counting information generating unit searches for sets of counting information, which counted a pair of annihilation radiations at substantially the same time, from a counting information list that is generated from output signals of the detector; generates a set of coincidence counting information for each retrieved set of counting information; and generates a time series list of coincidence counting information. Based on the time series list of coincidence counting information, the body movement detecting unit detects temporal changes in the body movement of the subject.