4D Contrast Enhanced CT Single Rotation Volumetric Imaging
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Solution Overview
Problem
Current 4D computed tomography (CT) scans with contrast enhancement face challenges in synchronizing the timing of the scan with peak contrast uptake in moving tissues, leading to potential missed contrast enhancement and repeated exposure to contrast material and radiation.
Innovation Solution
The method involves determining the location and full range of motion of a tissue of interest and performing a contrast-enhanced CT scan during a single rotation of the radiation source and detector array, concurrently imaging peak contrast enhancement and the entire volume of interest, using a system with a z-axis detector array for comprehensive coverage, and reconstructing a four-dimensional data set to capture peak contrast uptake without synchronizing with peak enhancement timing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a conventional 4D CT scan is performed with limited z-axis detector coverage (2.5 cm per rotation), then the scan can cover the entire tumor volume, but the scan time increases to about 80 seconds and requires multiple rotations or axial scans
Solution Approach 1:
The patent transitions from limited z-axis coverage (2.5 cm) to wide-area volumetric coverage (50 cm or more) by extending the detector array along the z-axis. This dimensional expansion allows the entire tumor volume to be captured in a single rotation, eliminating the need for multiple rotations or axial scans and reducing scan time from 80 seconds to a single rotation period.
Solution Approach 2:
The patent divides the large z-axis detector array into multiple segments or modules that can be arranged along the z-axis. This segmentation allows the system to achieve extensive volumetric coverage while maintaining manageable detector complexity and enabling flexible configuration for different scanning requirements.
2Measurement precision
If contrast enhancement timing is synchronized with respiratory gating in conventional scans, then peak contrast uptake can be captured, but the synchronization is difficult to achieve and may miss peak enhancement requiring re-scanning
Solution Approach 1:
The patent performs a preliminary test bolus scan to determine the approximate time to peak contrast uptake before the main scan. This preliminary measurement allows the system to pre-calculate the optimal contrast injection timing and duration, ensuring that peak enhancement occurs during the single rotation scan without requiring complex real-time synchronization during the actual imaging.
Solution Approach 2:
The patent dynamically adjusts the contrast injection protocol based on the measured time to peak uptake from the test bolus. The system modifies injection rate, timing, and duration in real-time based on patient-specific pharmacokinetics, allowing peak contrast enhancement to be captured during the single rotation even with respiratory motion, without requiring complex gate-synchronized triggering.
3Measurement precision
If multiple scans are performed to capture peak contrast enhancement, then desired contrast can be achieved, but the patient is exposed to multiple doses of contrast material and repeated radiation exposure
Solution Approach 1:
The patent implements a continuous scanning process that acquires data throughout the entire respiratory cycle and contrast enhancement period within a single rotation. Instead of performing discrete gated scans that may miss peak enhancement, the system continuously collects volumetric data and reconstructs images at all phases, ensuring peak contrast is captured without requiring repeat scans and minimizing contrast and radiation exposure to a single dose.
4Volume of moving object
If a wide-area detector array with 256 rows is used to achieve volumetric coverage in a single rotation, then the entire tumor volume can be imaged, but the detector complexity and data processing requirements increase
Solution Approach 1:
The patent divides the 256-row detector array into multiple independent segments or modules along the z-axis, each capable of independent readout and processing. This segmentation reduces the complexity of any single detector module, allows for modular manufacturing and assembly, and enables parallel data processing to handle the large volume of data from all 256 rows simultaneously during the single rotation scan.
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 accurate imaging of peak contrast uptake during a single revolution, reducing the need for repeated scans and minimizing patient exposure to contrast and radiation, while generating a 4D contrast-enhanced data set for effective treatment planning.
Implementation Method 1
a radiation source that rotates around an examination region about a z-axis and emits radiation that traverses the examination region and a detector array, located across the examination region, opposite the radiation source, that detects radiation traversing the examination region
Data Source
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AI summary
A method includes performing a contrast enhanced computed tomography(CT) scan of tissue of interest of a subject, with an imaging system (100) having a radiation source (112) and a detector array (118), in which a peak contrast enhancement of the tissue of interest, a full range of motion of the tissue of interest, and an entire volume of interest of the tissue of interest are concurrently imaged during a single rotation of the radiation source and the detector array of the imaging system over an entire or a predetermined sub- portion of a breathing cycle.