Ultrasound image processing apparatus

An ultrasound image processing apparatus comprising a processor and a non-transitory medium embodying a program of instructions executable by the processor to configure said ultrasound image processing apparatus to perform a method comprising:

• performing a delay process to individually delay reception signals which are respectively output from a plurality of transducers contained in an ultrasound probe;
• combining the delayed reception signals for generating a phase-aligned reception signal;
• determining a noise evaluation value for the phase-aligned reception signal, based on the delayed reception signals;
• performing a noise reducing process on the phase-aligned reception signal based on the noise evaluation value for generating a noise-reduced reception signal;
• and
• generating image data based on the noise-reduced reception signal,
• the noise reducing process including performing an adjustment process on the noise evaluation value to generate a weight for the noise evaluation value and multiplying the phase-aligned reception signal by the weight,
• the adjustment process including acquiring the weight for the noise evaluation value based on a conversion function of associating the noise evaluation value with the weight,
• the conversion function giving a lower limit to the weight,
• the conversion function having been selected from a plurality of different candidate functions of associating the noise evaluation value with the weight, based on a position in a depth direction where the noise evaluation value is obtained, and
• each of the plurality of candidate functions giving a different lower limit to the weight.

An ultrasound image processing apparatus comprising a processor and a non-transitory medium embodying a program of instructions executable by the processor to configure said ultrasound image processing apparatus to perform a method comprising:

• performing a delay process to individually delay reception signals which are respectively output from a plurality of transducers contained in an ultrasound probe;
• combining the delayed reception signals for generating a phase-aligned reception signal;
• determining a noise evaluation value for the phase-aligned reception signal, based on the delayed reception signals;
• performing a noise reducing process on the phase-aligned reception signal based on the noise evaluation value for generating a noise-reduced reception signal;
• generating image data based on the noise-reduced reception signal;
• generating the phase-aligned reception signal for each of a plurality of reception beams generated by a scan,
• the method further including the following aspects (i) or (ii):
• (i) the noise reducing process including performing an adjustment process on the noise evaluation value to generate a weight for the noise evaluation value and multiplying the phase-aligned reception signal by the weight,
• determining a weight distribution representing a distribution of weights in a scanning region where the reception beams are scanned, and
• determining, based on the weight distribution, whether a region contained in an image represented by the image data is an acoustic noise region or a structure region which is not the acoustic noise region;
• (ii) determining an evaluation value distribution representing a distribution of noise evaluation values in a scanning region where the reception beams are scanned,
• determining, based on the evaluation value distribution, whether a region contained in an image represented by the image data is an acoustic noise region or a structure region which is not the acoustic noise region;
• and
• applying image filters to the image data, the image filters being different between the acoustic noise region and the structure region, and
• performing an opening operation on the acoustic noise region and performing a closing operation on the structure region wherein the acoustic noise region and the structure region are both contained in an image represented by the image data.