C-arm X-ray 3D Subtraction Imaging with Sliding Window
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Solution Overview
Problem
Current methods for recording 3D vascular images using C-arm x-ray apparatuses are unable to capture sufficient projection image data during the arterial phase of the contrast agent bolus, leading to inadequate separation of arterial and venous phases, and require multiple administrations of contrast agents, causing contrast deterioration over time.
Innovation Solution
The method employs a 'sliding window' technique to record a higher density of projection image data records across a larger rotation angle of up to 360° before and after contrast agent administration, allowing for the reconstruction of 3D image data records that capture both arterial and venous phases with a single contrast agent administration, enabling separate or overlaid displays of arteries and veins.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple rotation runs are performed after contrast agent administration, then sufficient projection image data records can be obtained for 3D reconstruction, but the contrast agent deteriorates over time due to distribution throughout the vascular system
Solution Approach 1:
The method segments the vascular imaging process into two distinct phases: arterial phase imaging performed immediately after contrast administration, and venous phase imaging performed after a time delay. This segmentation allows separate 3D image data records to be created for each phase using the same contrast agent bolus, avoiding the need for multiple administrations while maintaining image quality
Solution Approach 2:
The method performs preliminary action by acquiring all necessary projection images during a single continuous rotation run after contrast administration. By pre-planning the rotation angle range to cover both arterial and venous phase requirements in one go, the system eliminates the need for subsequent rotation runs that would otherwise be required to capture adequate data
2Loss of time
If a single rotation run is performed after contrast agent administration, then the recording time is reduced, but insufficient projection image data records are obtained during the arterial phase
Solution Approach 1:
The method applies dynamics by implementing a sliding window approach where the evaluation window for arterial phase images dynamically adjusts based on the contrast agent bolus passage. The system continuously monitors projection images and identifies the optimal time window for arterial phase extraction, adapting to variations in contrast flow and patient anatomy
Solution Approach 2:
The method changes parameters by adjusting the rotation speed and angular resolution during different phases of the rotation run. The system varies the temporal and angular sampling density to optimize capture of the rapidly changing arterial phase while still acquiring sufficient data for subsequent venous phase imaging
3Productivity
If multiple administrations of contrast agent are performed, then sufficient projection image data records can be obtained for separate arterial and venous 3D images, but the contrast quality deteriorates with each subsequent administration
Solution Approach 1:
The method maintains continuity of useful action by performing a single uninterrupted rotation run that continuously acquires projection images throughout the entire contrast agent passage. This continuous acquisition captures both arterial and venous phase information in one go, eliminating the need for multiple discrete contrast administrations while preserving contrast quality throughout the imaging process
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 allows for the generation of multiple 3D subtraction image data records at any phase of the contrast agent bolus, improving diagnostic capabilities by enabling precise separation of arterial and venous phases and reducing the need for multiple contrast agent administrations, thus maintaining contrast quality.
Implementation Method 1
C-arm x-ray apparatus, x-ray source, wherein an x-ray radiation is switched on and off
Data Source
AI summary
A method for recording at least two 3D subtraction image data records with a C-arm x-ray apparatus is provided. A mask run is implemented with a rotation angle of at least 180° plus fan angle plus an additional angle, while projection image data record of a native 3D image data record are recorded. A filler run is implemented after administration of a contrast agent with a rotation angle of at least 180° plus fan angle plus an additional angle. Partial 3D image data records are generated and formed into a set of projection image data records. Each set of projection image data records is reconstructed, wherein a 3D subtraction image data record is generated by subtracting data of a native 3D image data record from data of a 3D image data record after the administration of the contrast agent.