Personalized Phantom Deformation for CT Dose Estimation
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Solution Overview
Problem
Current methods for estimating patient radiation exposure during CT scans are inaccurate due to the inability to measure radiation absorption in live patients directly and the inadequacy of existing imaging phantoms in representing individual variations in size and weight, leading to poor and varying results.
Innovation Solution
A computer-implemented method generates a personalized imaging model by deforming an initial phantom based on patient-specific anatomical landmarks and parameters, using Monte Carlo simulations to estimate radiation absorption, and interpolating between previous simulations to provide real-time dose estimates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If physical imaging phantoms are used to represent patients, then dose estimation can be performed, but the phantoms do not adequately represent individual variations in size and weight leading to poor and varying results
Solution Approach 1:
The patent creates virtual copies (digital phantoms) of patient anatomy from actual CT scan data, replacing physical phantoms. These virtual models precisely replicate individual patient characteristics including size, weight, and anatomical variations, enabling accurate dose estimation tailored to each patient's unique physiology.
Solution Approach 2:
The patent transforms fixed physical phantom parameters into variable digital parameters that can be adjusted to match individual patient characteristics. By modifying the virtual phantom's anatomical parameters based on actual patient scan data, the system adapts the dose estimation model to each patient's specific size, weight, and body composition.
2Ease of operation
If single point surface measurements are used for dose estimation, then measurements can be obtained, but the results are poor and widely varying depending on measurement location
Solution Approach 1:
The patent transitions from single-point surface measurements to three-dimensional volumetric analysis of the entire patient anatomy. By modeling the patient as a 3D virtual phantom and calculating radiation dose throughout the volume, the system eliminates location-dependent variability and provides comprehensive dose assessment of all internal organs and tissues.
Solution Approach 2:
The virtual phantom model serves multiple functions simultaneously: it represents the patient's external dimensions, internal organ locations, tissue densities, and radiation absorption characteristics. This multi-functional model provides consistent dose estimation across all measurement points and locations without requiring separate measurement procedures.
3Measurement precision
If cadaver results are used for dose estimation, then more accurate absorption data can be obtained, but the results do not correspond well to dose absorption in live tissues
Solution Approach 1:
The system uses the patient's own actual CT scan data to generate their personalized virtual phantom, eliminating the need to rely on cadaver data or population averages. Each patient's unique anatomical structure, tissue composition, and body geometry are captured from their own imaging data, ensuring the dose estimation reflects their specific physiology.
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 provides more accurate and consistent radiation dose estimates, enabling better tracking of cumulative doses and ensuring patient safety by maintaining records of radiation exposure in a format accessible for informed decision-making.
Implementation Method 1
a CT scanning system uses ionizing radiation (X-rays) to generate images of tissues, organs, and other structures within a body
Implementation Method 2
simulating the imaging scan using the deformed imaging phantom and the received set of parameters, and estimating, based on the simulation, amounts of radiation absorbed by the individual
Data Source
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AI summary
The invention describes a non-transitory computer-readable storage medium storing one or more application programs, which, when executed by a processor, performs an operation for providing a plurality of medical imaging providers with estimates of radiation dose absorbed by individuals receiving imaging scans, the operation comprising: receiving, from one of the medical imaging providers, a request for an estimate of radiation dose absorbed by an individual patient in receiving an imaging scan, wherein the request includes (i) a set of parameters describing the imaging scan and an image scanning apparatus being used to perform the imaging scan and (ii) one of a deformed mathematical phantom based on a body morphology of the individual patient and a transformation used to deform an initial mathematical phantom into the deformed mathematical phantom wherein the deformed mathematical phantom is determined via a method including: selecting an initial mathematical phantom for the individual patient receiving an imaging scan, the selecting being based on an age and a gender of the individual patient; receiving one or more scout images of the individual patient; selecting from images obtained from multiple individuals a reference set of localizer images having a body geometry, size and positioning that closely matches the initial mathematical phantom; determining a transformation between at least one of the localizer images and at least one of the scout images of the individual patient; and deforming the initial mathematical phantom based on the transformation whereby the deformed mathematical phantom resulting from the transformation better matches a size, a shape and organ positions of the individual patient; accessing a library comprising a plurality of previously completed simulations corresponding to one or more individuals, each of the previously completed simulations having information therein comprising a previous set of parameters describing a previous imaging scan and an image scanning apparatus used to perform the previous imaging scan, a previous estimate of radiation dose absorbed by one of the one or more individuals in receiving the previous imaging scan and a previous deformed phantom used in calculating the previous estimate of radiation dose associated therewith; evaluating the plurality of previously completed simulations within the library by comparing the information therein with the set of parameters and the deformed mathematical phantom obtained as a result of the request; upon identifying within the library, based on the evaluation, the previously completed simulations having the information therein that matches within a specified tolerance measure the set of parameters and the deformed mathematical phantom obtained as a result of the request, using the identified previously completed simulations to determine the estimate of radiation dose absorbed by the individual patient in receiving the imaging scan; and returning, to the medical imaging provider, the estimate of radiation dose absorbed by the individual patient.