X-ray breast tomosynthesis enhancing spatial resolution including in the thickness direction of a flattened breast

An x-ray breast imaging system having multiple modes of operation comprising:

• a breast immobilizer configured to flatten a patient's breast in an imaging volume;
• an x-ray source and an x-ray imaging receptor configured to selectively operate in any one of the following system modes:
• (a) a mammography mode M, (b) a tomosynthesis mode T, and (c) an enhanced tomosynthesis mode ET;
• wherein (a) when in mode M the system produces a mammogram image Mp taken while the source and receptor are at fixed positions relative to the immobilizer, (b) when in mode T the system produces plural two-dimensional (2D) projection images Tp each taken from a respective position of the source in a source trajectory T around the immobilizer, and (c) when operating in mode ET the system produces 2D projection images ETp1 taken from respective positions of the source in a first source trajectory ET1 around the breast immobilizer and 2D projection images ETp2 taken from respective positions of the source in a second source trajectory ET2 around the immobilizer;
• a computer-implemented image processor configured to:
• (a) respond to mode M operation to process the image Mp into a display mammogram image Mpd, (b) respond to mode T operation to apply a first tomosynthesis image reconstruction processing to the images Tp and thereby produce reconstructed breast slice images Tr, and (c) respond to mode ET operation to apply a second tomosynthesis image reconstruction processing to the images ETp1 and ETp2 to produce reconstructed breast slice images ETr;
• wherein the spatial resolution at least in a breast compression direction is greater in one of images Tr and ETr than in the other of images Tr and ETr;
• and
• a display configured to selectively display images derived from one or more of images Mpd, Tr, and ETr.

An x-ray breast imaging system comprising:

• a breast immobilizer configured to flatten a patient's breast;
• an x-ray source and an x-ray imaging receptor configured to selectively image the breast in a narrow angle tomosynthesis sub-mode Tn and an a wide angle tomosynthesis sub-mode Tw, where in sub-mode Tn the receptor obtains respective two-dimensional (2D) projection tomosynthesis x-ray images Tnp in the course of the source traversing a narrower arc trajectory around the immobilizer and in sub-mode Tw the receptor obtains respective 2D projection images Twp in the course of the source traversing a wider arc trajectory around the immobilizer;
• a computer-implemented image processor configured to selectively operate in a Tn mode to apply tomosynthesis image reconstruction processing to images Tnp to reconstruct 3D breast slice images Tnr from projection images Tnp and in a Tw mode to apply tomosynthesis reconstruction processing to images Twp to reconstruct 3D breast slice images Twr from images Twp;
• and
• a display configured to display images related to said 3D reconstructed image.

An x-ray breast tomosynthesis method comprising:

• obtaining a first plurality of two-dimensional (2D) tomosynthesis projection images ETp1 by irradiating a patient's breast flattened in a thickness direction, from a respective plurality of first x-ray source positions distributed along a first trajectory of the source around the breast;
• obtaining a second plurality of two-dimensional (2D) tomosynthesis projection images ETp2 by irradiating the patient's breast from a respective plurality of second x-ray source positions distributed along a second, longer trajectory of the source around the breast;
• computer-processing the ETp1 and the ETp2 images into a breast slice images ETr in a tomosynthesis image reconstruction process utilizing both the ETp1 and the ETp2 images;
• and
• generating and displaying images derived from said ETr images.