Apparatus and process for medical imaging
A process for medical imaging, the process including: (i) receiving scattering data representing mono-static or multi-static measurements of scattering of electromagnetic signals from tissues of a body part of a subject at a plurality of different signal frequencies, wherein electromagnetic signals are emitted from one or more antennas and the corresponding scattered signals are measured by the one or more antennas; (ii) processing the scattering data to calculate electric field power values at each of a plurality of scattering locations of the subject's tissues within the body part and for each of the plurality of frequencies; (iii) for each of the scattering locations, summing the calculated electric field power values at the scattering location over the plurality of frequencies and the plurality of antennas to generate an image of the tissues within the body part; and (iv) iteratively updating a model of the tissues within the body part based on a comparison of the model with the generated image until a termination criterion is satisfied, wherein the updated model is output as an image of the subject's tissues within the body part.
1 . A process for medical imaging, the process including:
(i) receiving scattering data representing mono-static or multi-static measurements of scattering of electromagnetic signals from tissues of a body part of a subject at a plurality of different signal frequencies, wherein the electromagnetic signals are emitted from one or more antennas and the corresponding scattered electromagnetic signals are measured by the one or more antennas;
(ii) using at least one processor, processing the scattering data to calculate electric field power values at each of a plurality of scattering locations of the subject's tissues within the body part and for each of the plurality of different signal frequencies;
(iii) using the at least one processor, for each of the plurality of scattering locations, summing the calculated electric field power values at the respective scattering location over the plurality of different signal frequencies and the one or more antennas to generate an image of the tissues within the body part; and
(iv) using the at least one processor, iteratively updating a model of the tissues within the body part based on a comparison of the model with the generated image until a termination criterion is satisfied, wherein the updated model is provided as an output image of the subject's tissues within the body part.
2 . The process of claim 1 , wherein the measurements are multi-static measurements and the one or more antennas comprise a plurality of antennas, wherein the electromagnetic signals are selectively emitted from each of the plurality of antennas disposed about the body part and the corresponding scattered electromagnetic signals are measured by each of the plurality of antennas.
3 . The process of claim 1 , wherein the body part is a head and the tissues include brain tissues of the subject.
4 . The process of claim 1 , including:
(v) processing biodata of the subject using machine learning to select, from a library of templates, a base template as being the best match for the subject, wherein the templates represent respective models of example tissues of the body part of respective subjects, and the biodata of the subject represents at least age, gender, weight, and ethnicity of the subject;
(vi) processing the selected base template and measurements of outer dimensions and/or shape of the subject's body part to generate template data representing the model of the tissues within the subject's body part by geometrically transforming spatial coordinates of the selected template to match the measurements of the subject's body part.
5 . The process of claim 1 , wherein the step of processing the scattering data includes the steps of:
(v) normalising and removing clutter from the scattering data; and
(vi) processing the normalised and clutter removed scattering data to calculate the electric field power values.
6 . The process of claim 5 , wherein removing clutter from the scattering data includes determining an average value of the measured scattered electromagnetic signals and subtracting the average value from each scattered electromagnetic signal measurement at each frequency to remove strong reflections and clutter from the scattering data.
7 . The process of claim 1 , including calibrating the scattering data by dividing measured scattering parameters for the body part by measured scattering parameters of an imaging domain in absence of the body part and with the imaging domain filled by a material with dielectric properties of a matching medium or an average body part phantom.
8 . The process of claim 1 , including classifying abnormal tissues within the body part as haemorrhagic or ischemic, by converting the scattering data from a frequency domain to a time-domain and mapping the time-domain scattering data to a corresponding graph, determining node degree and degree sequence properties of the graph, calculating graph degree mutual information to assess similarity of graphs, and training a classifier with a training set of graph degree mutual information features and their corresponding class labels and applying the classifier to the graphs calculated for the subject's tissues within the body part.
9 . The process of claim 1 , wherein the one or more antennas comprise a plurality of antennas and the process includes comparing the scattering data from corresponding pairs of opposed antennas among the plurality of antennas to identify significant differences between the scattering data for different hemispheres of the subject's brain, these being indicative of an abnormality in one of the hemispheres.
10 . A non-transitory computer-readable storage medium having stored thereon processor-executable instructions that, when executed by the at least one processor of a medical imaging system, cause the at least one processor to execute the process of claim 1 .
11 . An apparatus for medical imaging, including:
(i) an input to receive scattering data representing mono-static or multi-static measurements of scattering of electromagnetic signals from tissues of a body part of a subject at a plurality of different signal frequencies, wherein the electromagnetic signals are emitted from one or more antennas and the corresponding scattered electromagnetic signals are measured by the one or more antennas; and
(ii) a processor configured to:
process the scattering data to calculate electric field power values at each of a plurality of scattering locations of the subject's tissues within the body part and for each of the plurality of different signal frequencies;
for each of the plurality of scattering locations, sum the calculated electric field power values at the respective scattering location over the plurality of different signal frequencies and the one or more antennas to generate an image of the tissues within the body part; and
iteratively update a model of the tissues within the body part based on a comparison of the model with the generated image until a termination criterion is satisfied, wherein the updated model is provided as an output image of the subject's tissues within the body part.
12 . The apparatus of claim 11 , wherein the measurements are multi-static measurements and the one or more antennas comprise a plurality of antennas, wherein the electromagnetic signals are selectively emitted from each of the plurality of antennas adapted to be disposed about the body part and the corresponding scattered electromagnetic signals are measured by each of the plurality of antennas.
13 . The apparatus of claim 11 , wherein the body part is a head and the tissues include brain tissues of the subject.
14 . The apparatus of claim 11 , including a template generator to:
process biodata of the subject using machine learning to select, from a library of templates, a base template as being the best match for the subject, wherein the templates represent respective models of example tissues of the body part of respective subjects, and the biodata of the subject represents at least age, gender, weight, and ethnicity of the subject; and
process the selected base template and measurements of outer dimensions and/or shape of the subject's body part to generate template data representing the model of the tissues within the subject's body part by geometrically transforming spatial coordinates of the selected template to match the measurements of the subject's body part.
15 . The apparatus of claim 11 , wherein the processor is configured to process the scattering data by:
(v) normalising and removing clutter from the scattering data; and
(vi) processing the normalised and clutter removed scattering data to calculate the electric field power values.
16 . The apparatus of claim 15 , wherein the processor is configured to remove clutter from the scattering data by determining an average value of the measured scattered electromagnetic signals and subtracting the average value from each scattered electromagnetic signal measurement at each frequency to remove strong reflections and clutter from the scattering data.
17 . The apparatus of claim 11 , wherein the processor is further configured to calibrate the scattering data by dividing measured scattering parameters for the body part by measured scattering parameters of an imaging domain in absence of the body part and with the imaging domain filled by a material with dielectric properties of a matching medium or an average body part phantom.
18 . The apparatus of claim 11 , wherein the processor is further configured to classify abnormal tissues within the body part as haemorrhagic or ischemic, by converting the scattering data from a frequency domain to a time-domain and mapping the time-domain scattering data to a corresponding graph, to determine node degree and degree sequence properties of the graph, to calculate graph degree mutual information to assess similarity of graphs, and to train a classifier with a training set of graph degree mutual information features and their corresponding class labels and apply the classifier to the graphs calculated for the subject's tissues within the body part.
19 . The apparatus of claim 11 , wherein the one or more antennas comprise a plurality of antennas and wherein the processor is further configured to compare the scattering data from corresponding pairs of opposed antennas among the plurality of antennas to identify significant differences between the scattering data for different hemispheres of the subject's brain, these being indicative of an abnormality in one of the hemispheres.