Ultrasound image artefact reduction

A method for reducing an artefact in an ultrasound image of biological tissue, the biological tissue comprising an object that has different attenuation than surrounding tissue, wherein the object comprises a cyst, a ventricle, a fluid-filled cavity, or a natural or surgically-created opening;

• the method comprising:
• obtaining an ultrasound image of the biological tissue including the object that has different attenuation than the surrounding tissue;
• identifying the object in the ultrasound image;
• identifying a region of the ultrasound image that has an enhancement or shadowing artefact caused by the different attenuation of the object, wherein the region is identified based on one or more of:
• geometry of a transducer used to obtain the ultrasound image, a beam angle of transmitted ultrasound pulse(s) used to obtain the ultrasound image, and a distance of propagation of the ultrasound pulse(s) in the object;
• and
• applying a spatially varying gain correction to the identified region to compensate for the difference in attenuation of the object, wherein the gain correction is determined by:
• (i) minimizing a difference in intensity between the region of the ultrasound image that has an enhancement or shadowing artefact caused by the different attenuation of the object and a region of the ultrasound image that is not affected by the artefact, wherein the region of the ultrasound image that has the enhancement or shadowing artefact and the region of the ultrasound image that is not affected by the artefact are at a similar depth;
• wherein the region of the ultrasound image that is not affected by the artefact comprises multiple areas positioned in a grid arrangement or one or more windows sliding over the region that has the enhancement or shadowing artefact;
• or
• (ii) based on an apparent difference in attenuation for an ultrasound pulse propagating in the biological tissue including the object and the surrounding tissue compared to an ultrasound pulse propagating an equivalent distance in a homogeneous tissue, the homogenous tissue having the same attenuation coefficient as the surrounding tissue, wherein the apparent difference in attenuation is calculated as:
• ATN_D(R)=(A1−A0)*(L1−R)*f0
• wherein R is the distance along a trajectory of the ultrasound pulse away from a point at which the ultrasound pulse exits the object, A1 is the attenuation coefficient of the object, A0 is the attenuation coefficient of the surrounding tissue and the homogeneous tissue, L1 is the distance the ultrasound pulse travels in the object along the given trajectory, and f0 is a frequency of the ultrasound pulse;
• wherein the gain correction is applied in real-time to an ultrasound scanner, and wherein the method comprises subsequently using the ultrasound scanner to obtain a second ultrasound image of the biological tissue including the object.