Photoacoustic breast scanner

Apparatus for imaging tissue structures in a three-dimensional volume of tissue by detecting localized absorption of electromagnetic waves in said tissue, comprising

• an electromagnetic radiation source;
• a plurality of acoustic sensors arrayed across a surface, said surface being acoustically coupled to said tissue;
• power circuitry pulsing said electromagnetic radiation source to produce a pulse of diffuse electromagnetic radiation from said source irradiating said three-dimensional volume of tissue to generate resultant pressure waveforms within said three-dimensional volume of tissue;
• and
• computing circuitry detecting resultant pressure waveforms arriving at said acoustic sensors, storing data representative of said waveforms, and combining a plurality of said detected pressure waveforms to derive an image, points in said image being derived by combining measures of pressure waveforms originating at points within said tissue.

A method of imaging tissue structures by detecting localized absorption of electromagnetic waves in said tissue, comprising

• providing a source of electromagnetic radiation in proximity to said tissue;
• providing a plurality of acoustic sensors;
• acoustically coupling said plurality of acoustic sensors to said tissue;
• irradiating said tissue with a pulse of electromagnetic radiation from said source to generate resultant pressure waveforms within said tissue;
• detecting said resultant pressure waveforms arriving at said acoustic sensors and storing data representative of said waveforms;
• combining a plurality of said detected pressure waveforms to derive a measure of pressure waveforms originating at a point distant from said acoustic sensors, by determining a distance between said point and a pressure sensor, computing a value related to a sum of the pressure waveform detected by said pressure sensor over a time period, said time period beginning substantially contemporaneous with said pulse of electromagnetic radiation and said time period having a duration equal to the time needed for sound to travel said distance through said tissue, repeating said determining and computing for additional pressure sensors and pressure sensor waveforms, and accumulating said sums to form said measure of pressure waveforms originating at said point;
• and
• repeating said combining step for a plurality of points to produce an image of structures in said tissue.

A method of imaging tissue structures by detecting localized absorption of electromagnetic waves in said tissue, comprising

• providing a source of electromagnetic radiation in proximity to said tissue;
• providing a surface and positioning a plurality of acoustic sensors spaced across said surface in a spiral path;
• acoustically coupling said plurality of acoustic sensors to said tissue;
• positioning said surface and said sensors in a first position;
• irradiating said tissue with a pulse of electromagnetic radiation from said source to generate resultant pressure waveforms within said tissue;
• detecting said resultant pressure waveforms arriving at said acoustic sensors and storing data representative of said waveforms;
• rotating said surface and said sensors to a second position;
• repeating said irradiating step;
• repeating said detecting step;
• combining a plurality of said detected pressure waveforms collected by said sensors in said first and said second positions to derive a measure of pressure waveforms originating at a point distant from said acoustic sensors;
• and
• repeating said combining step for a plurality of points to produce an image of structures in said tissue.

A method of imaging tissue structures by detecting localized absorption of electromagnetic waves in said tissue, comprising

• providing an acoustic coupling media adjacent said tissue, having an acoustic characteristic impedance which is substantially similar to that of said tissue to reduce reflections of acoustic waves impinging into said media from said tissue;
• providing an electromagnetic coupling media adjacent said tissue, said electromagnetic coupling media having an electromagnetic characteristic impedance which is substantially similar to that of said tissue to reduce reflections of electromagnetic waves impinging into said tissue from said electromagnetic coupling media;
• providing a source of electromagnetic radiation in proximity to said tissue and immersing said source in said electromagnetic coupling media to electromagnetically couple said source to said tissue;
• providing a plurality of acoustic sensors and immersing said sensors in said acoustic coupling media to acoustically couple said plurality of acoustic sensors to said tissue;
• irradiating said tissue with a pulse of electromagnetic radiation from said source to generate resultant pressure waveforms within said tissue;
• detecting said resultant pressure waveforms arriving at said acoustic sensors and storing data representative of said waveforms;
• combining a plurality of said detected pressure waveforms to derive a measure of pressure waveforms originating at a point distant from said acoustic sensors;
• and
• repeating said combining step for a plurality of points to produce an image of structures in said tissue.

A method of imaging tissue structures by detecting localized absorption of electromagnetic waves in said tissue, comprising

• providing an coupling media adjacent said tissue, said coupling media having an acoustic characteristic impedance which is substantially similar to that of said tissue to reduce reflections of acoustic waves impinging into said media from said tissue, and having a characteristic electromagnetic impedance which is substantially similar to that of said tissue, to reduce reflections of electromagnetic waves impinging into said tissue from said media;
• providing a source of electromagnetic radiation in proximity to said tissue and immersing said source in said coupling media to electromagnetically couple said source to said tissue;
• providing a plurality of acoustic sensors and immersing said sensors in said coupling media to acoustically couple said plurality of acoustic sensors to said tissue;
• irradiating said tissue with a pulse of electromagnetic radiation from said source to generate resultant pressure waveforms within said tissue;
• detecting said resultant pressure waveforms arriving at said acoustic sensors and storing data representative of said waveforms;
• combining a plurality of said detected pressure waveforms to derive a measure of pressure waveforms originating at a point distant from said acoustic sensors;
• and
• repeating said combining step for a plurality of points to produce an image of structures in said tissue.

Apparatus for imaging tissue structures by detecting localized absorption of electromagnetic waves in said tissue, comprising

• an electromagnetic radiation source;
• a plurality of acoustic sensors arrayed across a surface along a spiral path, said surface being acoustically coupled to said tissue;
• a motor coupled to said surface for rotating said surface and said sensors;
• power circuitry pulsing said electromagnetic radiation source to produce a pulse of electromagnetic radiation from said source within said tissue;
• and
• computing circuitry detecting resultant pressure waveforms arriving at said acoustic sensors, storing data representative of said waveforms, and combining a plurality of said detected pressure waveforms to derive an image, points in said image being derived by combining measures of pressure waveforms originating at points within said tissue.

Apparatus for imaging tissue structures by detecting localized absorption of electromagnetic waves in said tissue, comprising

• a first tank containing an acoustic coupling media having an acoustic characteristic impedance which is substantially similar to that of said tissue to reduce reflections of acoustic waves impinging into said media from said tissue;
• a second tank containing an electromagnetic coupling media having an electromagnetic characteristic impedance which is substantially similar to that of said tissue to reduce reflections of electromagnetic waves impinging into said tissue from said electromagnetic coupling media;
• a plurality of acoustic sensors positioned within said first tank and immersed in said acoustic coupling media;
• an electromagnetic radiation source positioned inside of said second tank and immersed in said electromagnetic coupling media;
• power circuitry pulsing said electromagnetic radiation source to produce a pulse of electromagnetic radiation from said source within said tissue;
• and
• computing circuitry detecting resultant pressure waveforms arriving at said acoustic sensors, storing data representative of said waveforms, and combining a plurality of said detected pressure waveforms to derive an image, points in said image being derived by combining measures of pressure waveforms originating at points within said tissue.

Apparatus for imaging tissue structures by detecting localized absorption of electromagnetic waves in said tissue, comprising

• a tank containing a coupling media having an acoustic characteristic impedance which is substantially similar to that of said tissue to reduce reflections of acoustic waves impinging into said media from said tissue, and having an electromagnetic characteristic impedance which is substantially similar to that of said tissue to reduce reflections of electromagnetic waves impinging into said tissue from said coupling media;
• an electromagnetic radiation source positioned inside of said tank and immersed in said coupling media;
• a plurality of acoustic sensors positioned within said tank and immersed in said coupling media;
• power circuitry pulsing said electromagnetic radiation source to produce a pulse of electromagnetic radiation from said source within said tissue;
• and
• computing circuitry detecting resultant pressure waveforms arriving at said acoustic sensors, storing data representative of said waveforms, and combining a plurality of said detected pressure waveforms to derive an image, points in said image being derived by combining measures of pressure waveforms originating at points within said tissue.