Spectral CT Scan Protocol Determination for Tube Power Optimization

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Users often refrain from selecting spectral scanning in CT imaging due to scan mode restrictions that result in inefficient X-ray tube power usage, limiting acquisition speed and preventing the exploitation of enhanced spectral capabilities.

Innovation Solution

A method to determine a spectral scan protocol that distributes acquisition modes to meet conventional scan protocol restrictions, allowing for spectral acquisition without interfering with conventional scan protocols, by defining a proportion of first and second acquisition modes based on available headroom and optimizing tube power utilization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If spectral CT acquisition is performed using multiple X-ray beam spectra, then material decomposition and energy-selective reconstruction capabilities are improved, but X-ray tube power utilization efficiency deteriorates

Engineering Contradiction:
Improvespectral imaging capabilityVSAvoidX-ray tube power utilization efficiency
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The spectral CT acquisition is segmented into multiple individual CT acquisitions, each using a different X-ray beam spectrum. The system divides the spectral imaging task into separate acquisition passes at different tube voltages (e.g., 80 kVp and 140 kVp), allowing each acquisition to be optimized independently for power efficiency while collectively providing spectral information.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically adjusts the tube voltage between different acquisition passes to optimize power utilization. By switching between different voltage levels (e.g., alternating between 80 kVp and 140 kVp) rather than maintaining a fixed high voltage, the system adapts the energy output to match the specific requirements of each spectral component being acquired.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If spectral CT acquisition is performed, then spectral resolution and material differentiation are improved, but acquisition speed deteriorates due to scan restrictions

Engineering Contradiction:
Improvespectral resolutionVSAvoidacquisition speed
Core Design Contradiction:
Measurement precisionVSSpeed

Solution Approach 1:

The spectral imaging task is segmented into multiple sequential CT acquisitions at different energies. Rather than attempting to capture all spectral information in a single slow pass, the system performs multiple faster acquisitions at different tube voltages, combining them to achieve the desired spectral resolution while maintaining higher acquisition speed.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system employs periodic alternation between different tube voltage settings during the acquisition sequence. By rhythmically switching between low and high voltage modes across multiple rotations or passes, the system captures spectral information through periodic sampling, which maintains acceptable acquisition speed while building up the spectral data set.

Inventive Principle:
Principle #19Periodic action

3Use of energy by moving object

If conventional CT acquisition is used, then X-ray tube power utilization efficiency is improved, but spectral information and material decomposition capability are lost

Engineering Contradiction:
ImproveX-ray tube power utilization efficiencyVSAvoidspectral information
Core Design Contradiction:
Use of energy by moving objectVSLoss of information

Solution Approach 1:

The system merges multiple conventional CT acquisitions taken at different tube voltages into a unified spectral CT dataset. By combining the data from these separate power-efficient acquisitions, the system reconstructs images that contain spectral information enabling material decomposition, thus achieving spectral capabilities without sacrificing power utilization efficiency.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The multi-energy CT system performs multiple functions using the same hardware: it can operate as a conventional single-energy CT for routine scans, and as a spectral CT system for specialized applications. The same scanner and detector system universally handles both conventional and spectral acquisition modes, maximizing the utility of the imaging equipment.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

Enables spectral acquisition with similar image quality to conventional CT images, while reducing radiation dosage and maintaining conventional scan protocol restrictions, thus increasing the attractiveness of spectral acquisitions by eliminating scan mode restrictions.

Implementation Method 1

a first and a second X-ray beam spectrum are generated at a tube voltage of 80 kVp and 140 kVp, respectively

Methodology Applied
Scientific EffectX-ray generation: X-Ray

Implementation Method 2

measuring a transmission of the X-ray beams through the patient

Methodology Applied
Scientific EffectX-ray detection: X-Ray

Data Source

PatentEP3600048B1Method and device for determining a spectral computed tomography scan protocol
Publication Date: 2020.07.15 KONINKLIJKE PHILIPS NV
  • EP3600048B1 patent drawingFigure 1
  • EP3600048B1 patent drawingFigure 2~3
  • EP3600048B1 patent drawingFigure 4

AI summary

The present invention relates to a method (500) for determining a spectral scan protocol for acquiring a computed tomography (CT) image using a CT scanner and a corresponding apparatus (600). The method (500) comprises the steps of defining (510) a conventional scan protocol having scan restrictions for acquiring a conventional CT image; determining (520) a spectral scan protocol comprising a proportion of a first acquisition mode (201) and a proportion of a second acquisition mode (202), wherein the spectral scan protocol resembles the conventional scan protocol; and determining (520) the proportion of the first acquisition mode (201) and the proportion of the second acquisition mode (202) so that the scan restrictions of the conventional scan protocol are met. The method (500) and corresponding apparatus allows the determination of spectral scan protocols which reduce spectral scan mode restrictions.