Collision Avoidance in Cone-Beam CT Systems
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Cone beam computed tomography (CBCT) systems face challenges in avoiding collisions between the imaging apparatus and patients, particularly when imaging off-center anatomies, leading to unnecessary radiation exposure and prolonged operation times due to the trial-and-error repositioning process.
Innovation Solution
A method is developed to calculate a model of the subject based on prior image reconstructions and fluoroscopic exposures, assessing the likelihood of collision between the imaging apparatus and the subject or support, and adjusting the patient position to minimize collisions and optimize imaging within the field of view.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the patient is repositioned to avoid collisions between the imaging apparatus and the patient, then collision risk is reduced, but the operation time increases due to trial-and-error adjustments
Solution Approach 1:
The system performs preliminary calculations of the patient model and collision likelihood before the actual scan. By pre-computing the optimal positioning that avoids collisions, the system eliminates the need for trial-and-error adjustments during the procedure, thus reducing operation time while maintaining collision avoidance
Solution Approach 2:
The system uses feedback from prior image reconstructions and fluoroscopic exposures to continuously refine the patient model and adjust positioning calculations. This feedback mechanism enables the system to learn from previous scans and improve positioning accuracy, reducing both collision risk and adjustment time
2Manufacturing precision
If the patient is repositioned to ensure the anatomy of interest is within the field of view, then imaging quality is improved, but unnecessary radiation exposure may occur if positioning is incorrect
Solution Approach 1:
The system calculates the optimal patient positioning in advance based on the anatomy of interest and field of view geometry. By determining the correct position before radiation exposure begins, the system ensures that the anatomy is properly positioned within the field of view, eliminating the need for repeated scans and unnecessary radiation exposure
Solution Approach 2:
The system replaces manual trial-and-error positioning with automated computational modeling. By using computer-based calculations to determine optimal positioning, the system achieves precise positioning without the mechanical trial-and-error process that leads to unnecessary radiation exposure
3Adaptability or versatility
If the C-arm gantry rotates around an off-center portion of the patient, then the anatomy of interest is imaged, but the risk of collision between the detector/source and patient increases
Solution Approach 1:
The system performs preliminary collision risk assessment by calculating the patient model and evaluating the rotation trajectories of the source and detector. Before initiating the scan, the system determines whether the planned off-center positioning and rotation path will result in collisions, allowing operators to adjust the plan in advance
Solution Approach 2:
The patent introduces an intermediary computational model that mediates between the imaging requirements and collision avoidance. This patient model acts as an intermediary representation that allows the system to simulate and evaluate collision risks without actual physical trial-and-error movements
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 minimizes radiation exposure by avoiding collisions and reduces operation time by automating the positioning process, ensuring the anatomy of interest is imaged without unnecessary repositioning and radiation dose.
Implementation Method 1
x-rays emitted by the source in a cone-shaped beam are incident on and detectable by the x-ray detector
Implementation Method 2
calculating a model of the subject based on one or more of prior image reconstructions and fluoroscopic exposures
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Various methods and systems are provided for collision avoidance in cone- beam computed tomography (CT) systems. In one embodiment, a method for an imaging apparatus comprises calculating a likelihood of a collision between the imaging apparatus and a subject and/or its support based on a model of the subject, performing a scan of the subject responsive to the likelihood below a threshold, and not performing the scan otherwise. In this way, collisions between the patient and the imaging apparatus can be avoided.