System and method for acquiring optoacoustic data and producing parametric maps using subband acoustic compensation

Patent metadata

Field	Value
Publication number	US-9517055-B2
Application number	US-201314089484-A
Country	US
Kind code	B2
Filing date	Nov 25, 2013
Priority date	Oct 12, 2011
Publication date	Dec 13, 2016
Grant date	Dec 13, 2016

Abstract

A method is disclosed for generating sinograms by sampling transducers acoustically coupled with a surface of a volume after a pulse of light, each transducer being associated with a channel in an optoacoustic imaging system, and processing at least two multi-channel sinograms, each corresponding to a different one of the at least two different predominant wavelengths, to create at least two processed sinograms. The processing step includes a step of sub-band acoustic compensation. Image reconstruction is performed based upon the processed sinograms to generate at least two optoacoustic images. Image post processing is performed on the optoacoustic images to generate post-processed images. A parametric map is generated based upon information contained in the post-processed images, and an ultrasound image is generated using the transducers. The parametric map and the ultrasound image are co-registered and a co-registered image is displayed.

First claim

What is claimed is:

1. A method for creating and displaying images in an optoacoustic imaging system, comprising the steps of:
generating a plurality of multi-channel sinograms, each channel being generated by sampling a transducer acoustically coupled with a surface of a volume for a predetermined period of time after a pulse of light having a predominant wavelength selected from at least two different predominant wavelengths;
processing at least two of the plurality of multi-channel sinograms, each corresponding to a different one of the at least two different predominant wavelengths to create at least two processed sinograms, the step of processing each of the two multi-channel sinograms comprising sub-band acoustic compensation, wherein the step of sub-band acoustic compensation comprises:
establishing a filter bank of sub-band filters, the filter bank defining a plurality of sub-bands of the frequency domain;
applying the filter bank to each of the at least two multi-channel sinograms to create a filtered representation of each of the sinograms for each sub-band filter;
applying a narrowband simplification to each filtered representation of each of the sinograms for each sub-band filter to create a processed filtered representation of each of the sinograms for each sub-band filter;
reassembling the processed filtered representation of each of the sinograms for each sub-band filter to produce an acoustically compensated sinogram for each of the at least two multi-channel sinograms;
demodulating each filtered representation of each of the sinograms in the frequency domain prior to applying the narrowband simplification;
wherein the narrowband simplification is applied in the time domain to the demodulated filtered representations of each of the sinograms for each sub-band filter;

creating the at least two processed sinograms based upon the acoustically compensated sinograms;
creating two processed images from information contained in each of the processed sinograms; and
displaying at least one of the two processed images.

2. A method of producing a compensated time domain signal, comprising the steps of:
acquiring an acoustic time domain input signal;
converting the time domain signal to a frequency domain signal, the frequency domain signal comprising negative and non-negative frequency components;
providing a plurality of sub-band filters each defining a sub-band;
downsampling and demodulating portions of the frequency domain signal, which portions comprise only the non-negative frequency components, to produce downsampled demodulated portions, each of the downsampled demodulated portions corresponding to a sub-band;
filtering each of the downsampled demodulated portions with the corresponding one of the plurality of sub-band filters;
converting the filtered result into the time domain to produce complex-valued downsampled demodulated time domain sub-band signals;
providing a plurality of time domain compensation factors, each time domain compensation factor represented as function in the time domain defining the depth dependent acoustic compensation for each sub-band;
multiplying each of the plurality of time domain compensation factors with the corresponding complex-valued downsampled demodulated time domain sub-band signal to produce compensated complex-valued downsampled demodulated time domain sub-band signals;
converting each compensated complex-valued downsampled demodulated time domain sub-band signal to the frequency domain;
aligning the result in the frequency domain with frequency bands of the corresponding sub-band to produce modulated compensated frequency domain sub-band signals;
summing each modulated compensated frequency domain sub-band signal to produce a frequency domain output signal;
converting the frequency domain output signal to the time domain to produce an acoustically compensated time domain output signal; and
outputting the acoustically compensated time domain output signal.

3. A method for generating and displaying images in an optoacoustic imaging system, comprising the steps of:
generating a plurality of multi-channel sinograms, each being generated by sampling a plurality of transducers acoustically coupled with a surface of a volume for a predetermined period of time after a pulse of light having a predominant wavelength selected from at least two different predominant wavelengths, each transducer being associated with a channel in an optoacoustic imaging system;
processing at least two multi-channel sinograms, each corresponding to a different one of the at least two different predominant wavelengths to create at least two processed sinograms, the step of processing each of the two multi-channel sinograms comprising sub-band acoustic compensation;
performing image reconstruction based upon the at least two processed sinograms to generate at least two optoacoustic images;
performing image post processing on the at least two optoacoustic images to generate at least two post-processed images;
generating a parametric map based upon the information contained in the at least two post-processed images;
generating an ultrasound image using the plurality of transducers acoustically coupled with the surface of the volume;
co-registering the parametric map and the ultrasound image; and
displaying on a display an image formed from data in the co-registered parametric map and ultrasound image;
wherein the step of processing each of the two multi-channel sinograms comprises compensating time domain signals of the each of the two multi-channel sinograms, where each time domain signal of the time domain signals is compensated with steps comprising:
converting the time domain signal to a frequency domain signal, the frequency domain signal comprising negative and non-negative frequency components;
providing a plurality of sub-band filters each defining a sub-band;
downsampling and demodulating portions of the frequency domain signal, which portions comprise only the non-negative frequency components, to produce downsampled demodulated portions, each of the downsampled demodulated portions corresponding to a sub-band;
filtering each of the downsampled demodulated portions with the corresponding one of the plurality of sub-band filters;
converting the filtered result into the time domain to produce complex-valued downsampled demodulated time domain sub-band signals;
providing a plurality of time domain compensation factors, each time domain compensation factor represented as function in the time domain defining the depth dependent acoustic compensation for each sub-band;
multiplying each of the plurality of time domain compensation factors with the corresponding complex-valued downsampled demodulated time domain sub-band signal to produce compensated complex-valued downsampled demodulated time domain sub-band signals;
converting each compensated complex-valued downsampled demodulated time domain sub-band signal to the frequency domain;
aligning the result in the frequency domain with frequency bands of the corresponding sub-band to produce modulated compensated frequency domain sub-band signals;
summing each modulated compensated frequency domain sub-band signal to produce a frequency domain output signal;
converting the frequency domain output signal to the time domain to produce an acoustically compensated time domain output signal; and
outputting the acoustically compensated time domain output signal.

4. A method for generating and displaying images in an optoacoustic imaging system, comprising the steps of:
generating a plurality of multi-channel sinograms, each being generated by sampling a plurality of transducers acoustically coupled with a surface of a volume for a predetermined period of time after a pulse of light having a predominant wavelength select

Assignees

• Seno Medical Instr Inc

Inventors

• Zalev Jason

Classifications

• G06T12/00

  Tomographic reconstruction from projections · CPC title

• A61B8/5207 Primary

  involving processing of raw data to produce diagnostic data, e.g. for generating an image · CPC title

• A61B8/5292 Primary

  using additional data, e.g. patient information, image labeling, acquisition parameters · CPC title

• A61B5/7425

  Displaying combinations of multiple images regardless of image source, e.g. displaying a reference anatomical image with a live image · CPC title

• A61B8/4281

  characterised by sound-transmitting media or devices for coupling the transducer to the tissue · CPC title