Automatic gain compensation in an ultrasound imaging system
First Claim
1. In a method for processing ultrasound signals, the improvement comprising:
- receiving a current set and a successive set of acoustic signals, each said acoustic signal in said current set having a range value, a cross-range value, and at least one imaging value;
defining a set of zones, each one zone in said set of zones having at least one range boundary and at least one cross-range boundary;
assigning acoustic signals to zones, said assigning step being responsive to the range and cross-range values of said acoustic signals;
defining a zone intensity value for each zone, each said zone intensity value being responsive to at least one said imaging value from said acoustic signals assigned to said zone;
selecting a plurality of zones;
determining a set of attenuation estimates in response to said zone intensity values for said selected plurality of zones; and
altering at least one signal of said current set or said successive set of acoustic signals in response to said attenuation estimates.
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Accused Products
Abstract
The invention includes a method and system for automatic gain compensation in an ultrasound imaging system. The method and system may be used in place of, or in addition to, gain compensation selected by an operator. Gain compensation may be in response to range, in response to cross-range, or in response to both. Ultrasound imaging data is partitioned into relatively small zones (such as regions selected in response to range and cross-range), and a zone intensity value representative of each zone is used to determine information, such as an average image intensity, about ultrasound signals reflected from objects being imaged in each zone. The zone intensity value can be determined during real-time image acquisition by special-purpose averaging hardware, so that a commercial programmable microprocessor may operate on the zone intensity values to generate a gain compensation curve, also in real-time. Only those zones whose intensity is determined to be from tissue reflection are used to determine gain variations with range. A set of row mean values and a set of attenuation estimates for each row of zones having like range is determined, allowing for lateral gain rolloff at image edges, and from which a global gain to be applied, and a gain curve to be applied, are determined.
160 Citations
84 Claims
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1. In a method for processing ultrasound signals, the improvement comprising:
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receiving a current set and a successive set of acoustic signals, each said acoustic signal in said current set having a range value, a cross-range value, and at least one imaging value; defining a set of zones, each one zone in said set of zones having at least one range boundary and at least one cross-range boundary; assigning acoustic signals to zones, said assigning step being responsive to the range and cross-range values of said acoustic signals; defining a zone intensity value for each zone, each said zone intensity value being responsive to at least one said imaging value from said acoustic signals assigned to said zone; selecting a plurality of zones; determining a set of attenuation estimates in response to said zone intensity values for said selected plurality of zones; and altering at least one signal of said current set or said successive set of acoustic signals in response to said attenuation estimates. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43)
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44. In an apparatus for processing ultrasound signals, the improvement comprising:
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an ultrasound transducer array capable of generating and receiving acoustic signals, each said acoustic signal having a range value, a cross-range value, and an imaging value; a preprocessor coupled to said acoustic signals, said preprocessor generating a preprocessor signal representative of a set of zone intensity values responsive to said range values, cross-range values, and imaging values; a processor coupled to said preprocessor signal, said processor generating a gain compensation signal responsive to said zone intensity signals; and an amplifier coupled to said acoustic signals and to said gain compensation signal. - View Dependent Claims (45, 46, 47, 48, 49)
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50. In an apparatus for processing ultrasound signals, the improvement comprising:
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means for receiving a current set and a subsequent set of ultrasound data, each said set of data comprising a set of acoustic signals, each said acoustic signal having a depth value, a cross-range value, and at least one imaging value; means for assigning said acoustic signals to a plurality of zones in response to said cross-range value and said depth value; means for designating a zone intensity value for each said zone in response to said at least one imaging value for at least one acoustic signal in each said zone; means for selecting a plurality of said zones in response to said zone intensity values; means for determining a set of attenuation estimates in response to said zone intensity values for said selected plurality of zones; means for determining a gain compensation curve in response to said attenuation estimates; and means for applying said gain compensation curve to said subsequent set of ultrasound data to produce a set of gain compensated data for display or storage. - View Dependent Claims (51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80)
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81. In an apparatus for processing ultrasound signals, the improvement comprising:
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means for receiving a set of acoustic signals, each said acoustic signal having a cross-range value, a depth value, and an imaging value; means for digitizing said acoustic signals; means for determining a first gain compensation curve applied to said acoustic signals in response to a prior set of said acoustic signals, and for removing said first gain compensation curve; means for defining a set of zone intensity values, each said zone intensity value being responsive to at least one said imaging value in a set of said acoustic signals defining a zone, said zone being responsive to said cross-range value of said digitized acoustic signals; means for defining a first set of valid zones having said zone intensity values within a selected band, and for defining a second set of zones neighboring said valid zones and having said zone intensity values near those of said valid zones; means for defining a set of valid rows of zones, each having at least a threshold number of valid zones in a selected region of said row of zones; means for determining a set of attenuation estimates in response to said zone intensity values for a selected plurality of zones; means for determining a set of attenuation estimates for a set of non-selected zones in response to said attenuation estimates for said selected plurality of zones; means for defining a parabola, fitting said set of attenuation estimates for a selected set of range values near an endpoint of said set of attenuation estimates, for selecting a peak point of said fitted curve, and for modifying said set of attenuation estimates from said peak point to said endpoint; means for altering said acoustic signals in response to said attenuation estimates; means for scan converting said altered acoustic signals; and means for displaying said scan converted acoustic signals. - View Dependent Claims (83)
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82. A gain compensation subsystem in an apparatus for processing ultrasound signals, which apparatus transmits and receives ultrasound signals, the subsystem comprising:
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a processor memory in which is resident; a) a representation of a set of acoustic signals, said acoustic signals each having a cross-range value, a depth value, and an imaging value; b) a set of zone intensity values for said acoustic signals, said zone intensity values being responsive to said range values, cross-range values, and imaging values; and c) a set of gain request values representative of gain compensating for attenuation of said acoustic signals, said gain request values being generated responsive to said zone intensity values. - View Dependent Claims (84)
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Specification