Stationary Multi-Source Tomography for Cardiac Imaging
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Solution Overview
Problem
Conventional CT scanners have suboptimal temporal resolution, particularly in dynamic cardiac studies, which is limited by the constraints of scanning speed and radiation exposure, especially in patients with irregular heart rates.
Innovation Solution
A dynamic multi-source image reconstruction apparatus and method that includes multiple reconstruction stages: a first stage for reconstructing intermediate images using compressed sensing, a second stage for prior-constrained reconstruction, and a refinement stage for deep prior refinement, utilizing a tensor dictionary and deep learning to improve temporal resolution and image quality from sparse and truncated data sets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If rotation speed is increased to improve temporal resolution, then temporal resolution is improved, but centrifugal force limits the maximum rotation speed
Solution Approach 1:
The patent divides the scanning system into multiple stationary source-detector pairs arranged in a circular array, replacing the single rotating assembly. This segmentation allows simultaneous data acquisition from multiple angles without rotation, eliminating centrifugal force constraints while improving temporal resolution through parallel measurement.
Solution Approach 2:
The patent replaces the mechanical rotation system with a stationary multi-source configuration. Instead of mechanically rotating a single source-detector assembly, the system uses multiple fixed sources and detectors that remain stationary, substituting mechanical motion with a static array geometry to achieve the same angular sampling.
2Speed
If ECG-gating is used to improve temporal resolution in cardiac imaging, then temporal resolution is improved, but radiation exposure increases due to continuous overlapped scanning
Solution Approach 1:
The patent employs periodic activation of individual x-ray sources in sequence rather than continuous operation of all sources. Each source is activated for a brief period corresponding to its angular position, creating a periodic scanning pattern that achieves temporal resolution comparable to ECG-gating while reducing cumulative radiation exposure through time-multiplexed operation.
Solution Approach 2:
The patent uses a subset of available source-detector pairs at any given time, activating only the necessary number of sources to achieve the required temporal resolution. This partial action approach avoids the excessive radiation exposure that would result from simultaneous activation of all sources, optimizing the balance between image quality and radiation dose.
3Speed
If multiple source-detector pairs are used to improve temporal resolution, then temporal resolution is improved, but device complexity increases
Solution Approach 1:
The patent merges the functions of multiple source-detector pairs into a single integrated stationary array system. By combining multiple measurement channels that operate simultaneously from fixed positions, the system achieves high temporal resolution while consolidating control and data processing architecture, reducing operational complexity compared to managing multiple independent rotating assemblies.
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 solution achieves high-quality, real-time three-dimensional CT images with improved temporal resolution, reducing the impact of heart rate variability and radiation exposure, enabling effective dynamic imaging of beating hearts with enhanced soft tissue resolution and reduced radiation dose.
Implementation Method 1
Each source-detector pair includes an x-ray source configured to emit an x-ray pulse
Implementation Method 2
the measured projection data y satisfies the Beer-Lambert law, i.e., y＝log(I0/I)
Implementation Method 3
A CT imaging system configured to provide parallel projection data capture may provide an improved temporal resolution relative to conventional CT scanners
Data Source
AI summary
In one embodiment, there is provided a dynamic multi-source image reconstruction apparatus. The apparatus includes a first reconstruction stage, a second reconstruction stage, and a refinement stage. The first reconstruction stage is configured to receive an input data set including a group of data frames. Each data frame corresponds to a respective time step. Each data frame includes a number of projection data sets. Each projection data set corresponds to a respective source-detector pair of a stationary multi-source tomography system. The first reconstruction stage is further configured to reconstruct a first intermediate image based, at least in part, on the group of data frames. The second reconstruction stage is configured to receive a selected data frame and to reconstruct a second intermediate image with a constraint of the first intermediate image as prior. The refinement stage is configured to refine the second intermediate image to produce a three-dimensional output image.