Motion-Compensated 3D Angiography for Cardiac Perfusion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current angiography systems face challenges in performing time-resolved cardiac perfusion measurements, especially in moving organs like the heart, due to limitations in time resolution and the inability to simultaneously account for cardiac phases and contrast-agent dynamics, leading to artifacts and inaccurate perfusion measurements.
Innovation Solution
A method that records a data set knowing the phase position of the examination object, extracts the motion field, and uses motion compensation to correct for object motion, allowing for simultaneous capture of cardiac phases and contrast agent dynamics, enabling accurate perfusion measurements without image blurring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If the C-arm rotates around the patient to generate 3D images, then three-dimensional imaging capability is improved, but time resolution deteriorates to typically 4 to 5 seconds
Solution Approach 1:
The patent segments the imaging process into multiple phases: a first 3D recording for motion compensation, and a second 3D recording for perfusion measurement. By dividing the imaging task into separate phases with different optimization goals, the system achieves both high spatial resolution (3D imaging) and improved time resolution (reduced to 2-3 seconds) without compromising either capability.
Solution Approach 2:
The patent performs a preliminary 3D recording to extract motion fields before performing the actual perfusion measurement recording. This preliminary action captures the motion characteristics of the heart, which are then used to compensate for motion artifacts in the subsequent perfusion imaging, enabling accurate time-resolved measurements despite cardiac motion.
2Reliability
If ECG gating is used for mapping the heart in 3D, then motion artifacts are reduced, but temporal resolution deteriorates severely making perfusion measurements impossible
Solution Approach 1:
The patent extracts motion fields from a first 3D recording and applies them as compensation to the second recording. By separating the motion compensation function from the perfusion measurement function, the system achieves motion artifact reduction without the severe temporal resolution loss that would result from traditional ECG gating requiring multiple rotational passes.
Solution Approach 2:
The patent changes the temporal parameters by reducing the number of rotational passes required for perfusion measurement from multiple (with ECG gating) to just one or few passes. The motion compensation technique allows accurate perfusion imaging with temporal resolution of 2-3 seconds, dramatically improving upon the severely degraded temporal resolution of traditionally gated approaches.
3Loss of information
If multiple rotational passes are performed for ECG gating, then cardiac phases are captured, but time resolution deteriorates and perfusion measurements become impossible
Solution Approach 1:
The patent merges the acquisition of cardiac phase information and perfusion dynamics into a single integrated process. By using motion fields extracted from initial recordings to compensate for cardiac motion during perfusion imaging, the system simultaneously captures both cardiac phase data and contrast agent dynamics without requiring separate multiple rotational passes, thus maintaining high temporal resolution.
4Productivity
If projection recordings are used for perfusion measurement, then recording speed is improved, but anatomical accuracy deteriorates due to inability to assign areas to 3D anatomy
Solution Approach 1:
The patent transitions from two-dimensional projection imaging to three-dimensional volumetric imaging for perfusion measurement. By acquiring and reconstructing 3D data sets with motion compensation, the system maintains the rapid recording capability while adding the crucial third dimension that enables accurate anatomical localization and assignment of perfusion measurements to specific cardiac structures.
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 method allows for meaningful cardiac perfusion measurements during interventions, improving time resolution and accuracy, and can be used directly in angiography systems without the need for transferring patients to other imaging systems, simplifying the workflow and enabling real-time perfusion information during treatment.
Implementation Method 1
an X-ray source and on the other end of which an associated X-ray detector is mounted... generating first and second projection recordings of the examination object from various angles
Implementation Method 2
an associated X-ray detector is mounted... for generating first and second projection recordings of the examination object from various angles
Data Source
AI summary
The invention relates to an operating method for an imaging system for the time-resolved mapping of an iteratively moving examination object. First recordings of the object are generated by the imaging system from various angles while simultaneously recording a phase signal. Multiple static 3D-image data sets corresponding to a sequence of defined phases are reconstructed from the first recordings. Three-dimensional motion fields are calculated from the 3D-image data sets, by which two 3D-image data sets are mapped onto one another. Second recordings of the object are generated by the imaging system from various angles while simultaneously recording a phase signal. 3D-image data sets from the second recordings in a previously determined reference phase of the phase signal using the motion fields is generated which is a sequence of motion-compensated 3D-image data sets.