Ultrasonic reflex transmission imaging method and apparatus

In a reflex transmission ultrasonic imaging system for imaging a section within a subject, said system comprising;

• a two-dimensional ultrasonic transducer array,
• transmitter means for energizing the transducer array for beaming ultrasonic energy waves into the subject for insonification of the section to be imaged, said transducer array receiving echo signals and converting the same to electrical signals,
• electronic focusing means responsive to received electrical signals from the transducer array for simultaneously focusing at an array of focal points at the section to be imaged and having a plurality of outputs equal in number to the number of points at which the transducer array is simultaneously focused,
• a plurality of signal processing channels each of which is responsive to an output from said electronic focusing means, each said channel being responsive to a signal produced by echo signals received from a range zone opposite the associated focal point for generating a pixel value related to attenuation of acoustic waves at the focal point.

In a reflex transmission ultrasonic imaging system for imaging a section within a subject, said system comprising;

• a focused linear transducer array that is focused along a line in the section to be imaged,
• transmitter means for energizing the transducer array for beaming ultrasonic energy waves into the subject that are focused along said line, said transducer array receiving echo signals and converting the same to electrical signals,
• electronic focusing means responsive to received electrical signals for simultaneously focusing the transducer array at a plurality of points along said line of focus and having a plurality of outputs equal in number to the number of points at which the transducer array is simultaneously focused, and
• a plurality of signal processing channels each of which channels is responsive to an output from said electronic focusing means, each said channel being responsive to a signal produced by echo signals received from a range zone opposite the associated focal point for generating a pixel value related to attenuation of acoustic waves at the focal point, and
• means for scanning the line of focus over the section to be imaged for imaging the section.

In an ultrasonic imaging method for imaging a section of the interior of a subject, the steps comprising,

• insonifying at least a portion of a plane to be imaged within the subject,
• receiving by a transducer array echo signals from scatterers within a range zone opposite the section to be imaged from the transducer array,
• while receiving echo signals, simultaneously focusing said transducer array at a plurality of focal points lying in the section to be imaged to produce a plurality of signal outputs equal in number to the number of focal points at which the transducer array is focused, and
• individually processing said signal outputs produced in response to reflected ultrasonic waves that are received by the transducer array from a range zone opposite the associated focal point for substantially simultaneously generating a plurality of pixel values that are substantially dependent upon and provide a measure of attenuation of ultrasonic waves at the focal points.

In an ultrasonic imaging method for imaging the interior of a subject, the steps comprising,

• insonifying at least a portion of a contoured surface to be imaged within the subject,
• receiving by a transducer array echo signals from discontinuities opposite the contoured surface from the transducer array,
• while receiving echo signals, simultaneously focusing said transducer array at a plurality of focal points lying substantially on the contoured surface to produce a plurality of signal outputs equal in number to the number of focal points at which the transducer array is focused, and
• individually processing said signal outputs produced in response to reflected ultrasonic waves that are received by the transducer array from range zones opposite the associated focal points for substantially simultaneously generating a plurality of pixel values that are substantially dependent upon and provide a measure of attenuation of ultrasonic waves at the focal points.

In an ultrasonic imaging system comprising transducer means for receiving ultrasonic signals reflected from within an object, the combination including

• means for focusing the transducer means at at least one focal point within the object,
• signal processing means responsive to reflected signals received by the transducer means from a range zone that is opposite the focal point from the transducer means for generating a pixel value which is substantially dependent upon and provides a measure of attenuation of ultrasonic waves at the focal point,
• means for halting processing of reflected signals by said signal processing means in response to a large change in amplitude of reflected signals from the range zone, and
• means for weighting pixel values from said signal processing means in an amount related to the portion of the range zone over which reflected signals are processed by said signal processing means.

In a reflex transmission ultrasonic imaging method for non-invasive examination of the interior of objects such as body parts from reflections from scatterers within the object of ultrasonic energy, steps including

• receiving by means of focused transducer means reflected ultrasonic energy and converting the same to electrical signals,
• detecting electrical signals from the transducer means,
• integrating detected signals over a time period during which reflected ultrasonic energy is received from a range zone having substantially uniform reflective properties that is opposite the point of focus from said transducer means, the integrated signal being related to attenuation at the point of focus,
• if the range zone does not have substantially uniform reflective properties, then integrating detected signals over a portion of said time period during which reflected ultrasonic energy is received from the range zone, and
• weighting the integrated signal in proportion to the portion of the image zone over which detected signals are integrated to establish a pixel value.