Method and system for providing a locally-consistent enhancement of a low-quality image
A method of providing a medical image of a ROI of a patient, the method comprising: acquiring a first medical image of a region of interest (ROI) of a patient, the medical image characterized by a first signal to noise ratio (SNR); determining for a given pixel in the first image a plurality of different first image patches in the first image, each having a pixel that is coincident with the given pixel; determining for each first image patch a similar second image patch having a second SNR greater than the first SNR; determining an enhanced pixel value for the given pixel having an enhanced SNR greater than the first SNR responsive to pixel values of pixels in the determined second image patches; and using the determined pixel value to generate a second medical image of the ROI having an enhanced SNR greater than the first SNR.
1. A method for providing a Locally-Consistent enhancement of a Low-Quality image (L-image) of a ROI to provide an Enhanced Image (E-image) of the ROI, wherein F(⋅) returns an enhanced pixel value EPV=“{circumflex over (p)} j ” for the given pixel p j that is computed as a function of H-patches belonging to a set {NNp j } of nearest neighbor H-patches, {circumflex over (P)} i , 1≤i≤P N , where P N is a number of pixels in the L-patch, the method further comprising:
selecting a pixel p j of the L-image to be enhanced;
(ii) defining a patch (L-patch) in the L-image, having P N pixels and comprising pixel p j ;
(iii) defining P N O-patches that have the same size as the L-patch, contain pixel p j and overlap at least a portion of the L-patch;
(iv) for each O-patch, returning from a relevant high-quality source (H-source), a high quality patch (H-patch) that satisfies a desired similarity criterion wherein the H-patches and L-images are acquired from different imaging systems;
(v) computing an enhanced pixel value (EPV) for p j , based on F(⋅); and
(vi) replacing the pixel value of p j with the computed EPV.
2. A method for providing a Locally-Consistent enhancement of a Low-Quality image (L-image) of a ROI to provide an Enhanced Image (E-image) of the ROI, wherein function (⋅) returns an average value of pixels from the H-patches that are homologous with a pixel in an O-patch coincident with the given pixel, in symbols
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the method further comprising:
(i) selecting a pixel pj of the L-image to be enhanced;
(ii) defining a patch (L-patch) in the L-image, having PN pixels and comprising pixel p j ;
(iii) defining P N O-patches that have the same size as the L-patch, contain pixel p j and overlap at least a portion of the L-patch;
(iv) for each O-patch, returning from a relevant high-quality source (H-source), a high quality patch (H-patch), that satisfies a desired similarity criterion wherein the H-patches and L-images are acquired from different imaging systems;
(v) computing an enhanced pixel value (EPV) for p j , based on function (·); and
(vi) replacing the pixel value of p j with the computed EPV.
3. A method for providing a Locally-Consistent enhancement of a Low-Quality image (L-image) of a ROI to provide an Enhanced Image (E-image) of the ROI, wherein function F(·) returns a sum of {circumflex over (P)} I J , i=1 . . . P N weighted by a distance measure between the overlapping pixels of {circumflex over (P)} i and the original L-patch defined for the given pixel p j , formalized as follows:
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the method further comprising:
(i) selecting a pixel p j of the L-image to be enhanced;
(ii) defining a patch (L-patch) in the L-image, having P N pixels and comprising pixel P j ;
(iii) defining P N O-patches that have the same size as the L-patch, contain pixel p j and overlap at least a portion of the L-patch;
(iv) for each O-patch, returning from a relevant high-quality source (H-source), a high quality patch (H-patch), that satisfies a desired similarity criterion wherein the H-patches and L-images are acquired from different imaging systems;
(v) computing an enhanced pixel value (EPV) for p j , based on function F(⋅); and
(vi) replacing the pixel value of p j with the computed EPV.
4. A system for providing an Enhanced Image (E-image) of a ROI based on a Locally-Consistent enhancement of a Low-Quality image (L-image) of the ROI, the system comprising:
(i) an E-processor having enhancement operation elements, that include set of instructions executable to implement a trained neural network said enhancement comprising:
a) selecting a pixel p j of the L-image to be enhanced;
b) defining a patch (L-patch) in the L-image, having P N pixels and comprising pixel p j ;
c) defining P N O-patches that have the same size as the L-patch, contain pixel p j , and overlap at least a portion of the L-patch;
d) for each O-patch, returning from a relevant high-quality source (H-source), a high quality patch (H-patch) that satisfies a desired similarity criterion;
e) computing an enhanced pixel value (EPV) for p j based on a function F(⋅) of the H-patches; and
f) replacing the pixel value of p j with the computed EPV;
(ii) a H-database and an L-database;
(iii) a PACS (Picture Archiving and Communication System) connected through DICOM protocol to E-processor, H-source and an L-database;
(iv) a medical imaging modality connected to the E-processor;
(v) a radiologic workstation communicating with the PACS system, for the retrieval of the E-images and their visualization;
(vi) a display; and
(vii) a human-machine interface (HMI).
5. Claim according to claim 1 and comprising repeating steps (i) to (vi).
6. Claim according to claim 2 and comprising repeating steps (i) to (vi).
7. Claim according to claim 3 and comprising repeating steps (i) to (vi).
8. Claim according to claim 4 and comprising repeating steps (a) to (f).