4D Angiography via Rotational DSA and 2D Temporal Projection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current angiography techniques face limitations in spatial and temporal resolution, particularly when imaging small and convoluted intracranial vasculature, leading to difficulties in distinguishing arterial from venous structures and visualizing complex vascular anatomy, which hinders accurate diagnosis and minimally invasive procedures.
Innovation Solution
A system and method for generating time-resolved, three-dimensional medical images with high temporal and spatial resolution by combining time-series of 2D images with static 3D rotational DSA images, using a single contrast injection and a single x-ray source and detector array, allowing for the separation of arterial and venous signals and improved visualization of vascular dynamics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If rotational acquisitions are obtained over a minimum time of about 5 seconds, then spatial resolution is improved, but temporal resolution deteriorates
Solution Approach 1:
The patent segments the rotational acquisition into multiple temporal phases (arterial phase, capillary phase, venous phase) and selectively reconstructs 3D volumes from specific angular ranges corresponding to each phase. This allows high spatial resolution 3D imaging while capturing temporal dynamics by processing different angular segments at different time points.
Solution Approach 2:
The patent transforms the traditional 2D temporal sequence into a 4D dataset by adding the angular dimension. Rotational projections acquired over time are reconstructed into 3D volumes with temporal tagging, creating a four-dimensional representation that preserves both spatial detail and temporal information simultaneously.
2Loss of information
If thresholding is applied to remove venous structures, then arterial image purity is improved, but measurement precision deteriorates
Solution Approach 1:
The patent applies dynamic temporal filtering that adapts thresholding parameters based on the contrast enhancement phase. During the arterial phase, higher thresholds remove venous structures; during the venous phase, lower thresholds are applied. This dynamic approach preserves measurement accuracy across different time points while maintaining arterial purity when needed.
Solution Approach 2:
The patent performs preliminary 3D reconstruction from rotational data before applying phase-specific thresholding. By reconstructing the complete 3D volume first, then applying temporal filters, the system preserves all spatial information initially and selectively removes venous contamination only in the arterial phase images, maintaining measurement precision for structures that require it.
3Loss of information
If multiple contrast injections are performed, then vascular structure visualization is improved, but device complexity and procedure time increase
Solution Approach 1:
The patent makes the single rotational acquisition multi-functional by reconstructing multiple 3D volumes from the same dataset, each optimized for different vascular phases. The same rotational data serves both arterial phase imaging and venous phase imaging needs, eliminating the requirement for separate contrast injections while providing comprehensive vascular visualization.
Solution Approach 2:
The patent changes reconstruction parameters (angular range, temporal phase, thresholding levels) from the single rotational dataset to generate multiple specialized 3D volumes. By varying these parameters during post-processing, the system achieves what would traditionally require multiple injections, reducing procedure complexity while maintaining comprehensive vascular visualization.
4Manufacturing precision
If rotational acquisition time is extended, then spatial resolution is improved, but contrast medium requirements increase
Solution Approach 1:
The patent captures the continuous contrast passage through the vasculature during a single rotational acquisition, utilizing the entire temporal sequence from arterial to venous phase. This continuous capture approach maximizes the information extracted from a single contrast bolus, achieving high spatial resolution without requiring additional contrast medium for extended imaging.
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 approach provides detailed, time-resolved 3D images with enhanced spatial and temporal resolution, enabling clearer visualization of vascular anatomy and flow patterns, reducing the need for multiple contrast injections and minimizing complications, and facilitating more accurate pre-treatment planning and interventional procedures.
Implementation Method 1
using a single contrast injection and a single x-ray source and detector array
Implementation Method 2
reconstructing a three-dimensional image substantially without temporal resolution from at least a portion of the acquired image data
Data Source
Figure 1A~1B
Figure 2
Figure 3
AI summary
A method for generating time-resolved 3D medical images of a subject by imparting temporal information from a time-series of 2D medical images into 3D images of the subject. Generally speaking, this is achieved by acquiring image data using a medical imaging system, generating a time-series of 2D images of a ROI from at least a portion of the acquired image data, reconstructing a 3D image substantially without temporal resolution from the acquired image data, and selectively combining the time series of 2D images with the 3D image. Selective combination typically involves registering frames of the time-series of 2D images with the 3D image, projecting pixel values from the 2D image frames "into" the 3D image, and weighting the 3D image with the projected pixel values for each frame of the time-series of 2D images. This method is particularly useful for generating 4D-DSA images (that is, time-resolved 3D-DSA images) from a time-series of 2D-DSA images acquired via single plane or biplane x-ray acquisitions with 3D images acquired via a rotational DSA acquisition. 4D-DSA images can be generated either by using multiple injections or by using a single injection by combining a time-series of 2D-DSA images generated from individual projections from a rotational x-ray acquisition with a 3D image reconstructed from substantially all of the projection views acquired during the rotational x-ray acquisition. These DSA images may have a spatial resolution on the order of 5123 pixels and a temporal resolution of about 30 frames per second, which represents an increase over traditional 3D-DSA frame rates by a factor of between 150 and 600.