Slope Constrained Cubic Interpolation for PET Image Artifacts

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Solution Overview

Problem

Traditional interpolation methods for PET data, such as linear and cubic interpolation, degrade image resolution and introduce artifacts around high contrast objects, particularly in edge-preserving reconstructed PET data, leading to blurred edges and negative values that can confuse diagnosis.

Innovation Solution

The method employs slope constrained cubic interpolation, where the slope of the interpolation surface at each data point is limited by the data point's value, preventing negative values and preserving image resolution by calculating the interpolated data points based on surrounding reconstructed data points using a slope-limited bicubic spline.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If cubic interpolation is used to preserve image resolution, then image resolution is maintained, but artifacts (negative values) are introduced around high contrast objects

Engineering Contradiction:
Improveimage resolutionVSAvoidartifacts around high contrast objects
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The patent modifies the cubic interpolation algorithm by introducing a slope constraint parameter that limits the maximum slope of the interpolation surface. By changing the parameter constraints on the interpolation function, the method maintains resolution while preventing negative values from forming around high contrast objects.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements a dynamic interpolation approach where the interpolation method adapts locally based on the characteristics of the data points. The slope constraint is adjusted according to the local gradient and data values, allowing the algorithm to maintain high resolution in most areas while preventing artifacts in specific regions with high contrast transitions.

Inventive Principle:
Principle #15Dynamics

2Device complexity

If linear interpolation or nearest point interpolation is used, then computational simplicity is maintained, but image resolution is degraded and edges are blurred

Engineering Contradiction:
Improveinterpolation method complexityVSAvoidimage resolution
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent enhances simple linear or nearest-neighbor interpolation by introducing slope constraint parameters that modify the interpolation behavior. This allows the method to maintain computational simplicity while improving edge preservation and preventing the blurring effect of traditional linear interpolation.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If traditional interpolation methods are applied to edge-preserving reconstructed PET data, then processing speed is maintained, but edge sharpness is lost and images are blurred

Engineering Contradiction:
Improveinterpolation processing speedVSAvoidedge sharpness
Core Design Contradiction:
ProductivityVSShape

Solution Approach 1:

The patent implements a dynamic interpolation approach that adapts to local image characteristics. By evaluating local gradients and adjusting interpolation parameters accordingly, the method maintains processing speed while preserving edge sharpness in regions with high contrast transitions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent modifies the interpolation parameters dynamically based on local image features. The slope constraint parameters are adjusted according to the local gradient magnitude, allowing fast processing while maintaining edge sharpness where needed.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS10332252B2Slope constrained cubic interpolation
Publication Date: 2019.06.25 GE PRECISION HEALTHCARE LLC
  • US10332252B2 patent drawing
  • US10332252B2 patent drawing
  • US10332252B2 patent drawing

AI summary

Methods and systems are provided for interpolating acquired data of a tracer distribution. In one embodiment, a method comprises reconstructing the acquired data, and interpolating the reconstructed data with a surface, wherein a slope of the surface at a data point of the reconstructed data is limited by a value of the data point. In this way, interpolation artifacts around objects with high tracer density may be avoided.