The invention relates to a mammography-apparatus for detecting malignant cells in a breast comprising an x-ray source and an x-ray detector that cooperates with the x-ray source for providing an x-ray image of said breast, and further comprising a paddle for flattening the breast by pressing it against said x-ray detector, wherein a control system is provided which controls the actuation of the paddle according to a desired compression force that is to be applied to the breast. Pressing the breast with the paddle against the x-ray detector serves the purpose of the breast's flattening, which is desirable for getting a proper x-ray image of the breast.

The invention also relates to a method for detecting malignant cells in a breast using an x-ray source and an x-ray detector that cooperates with the x-ray source for providing an x-ray image of said breast, wherein prior to x-ray imaging first an initial moderate flattening force is applied to the breast by pressing the breast with the paddle against the x- ray detector which precedes the eventual flattening force during x-ray imaging.

US2016/0235379 discloses a method for optimizing x- ray imaging during a mammographic examination, wherein a breast is compressed between a support plate and a compression plate, and the force height curve of the breast is acquired during compressing, wherein an elasticity value of the breast is determined based on the force height curve and an optimization takes place of a parameter of the x-ray imaging system based on the determined elasticity value. Further a compres- sion force limit is determined based on one of the following quantities: a breast contact area, the stiffness of the breast, and the glandularity of the breast. For breasts with a high glandular tissue volume fraction, the applied compression force may be increased in agreement with the person under ex- amination.

WO2012/107057 discloses an image processing device for finding corresponding regions in two three-dimensional images of an object. The image processing device comprises to that end an image providing unit for providing a three- dimensional first image of the object and a three-dimensional second image of the object in first and second compression di ^¬ rections. An analytical compression model is matched to the first image showing the object compressed in the first com- pression direction, thereby determining the position of the first region of the object, which is provided in the first image in the compressed model. A second region in the second im ^¬ age, which corresponds to the first region in the first image, is determined by simulating a decompression of the compression model, simulating a compression of the compressing model in a second compressing direction, in which the object shown in the second image is compressed, and determining the region in the second image, which corresponds to the first region in the compression model compressed in the second compression direc- tion, as the second region.

An example of a mammography-apparatus and method according to the preamble is known from US2006/0245541. This document discloses a method and apparatus for compressing a patient's breast when using an x-ray mammography machine to take an image wherein said machine has a compression paddle and a bucky. A movable interface plate controllable by linear actuators is mounted on the bucky as an interface between the bucky and the patient's breast. The method includes steps wherein the compression paddle is moved downwardly to provide compression forces to the breast; the movement of the compression paddle is stopped at a position were less than the full desired compression of breast is attained. Next, the movable interface plate is elevated under the control of the linear actuators, upwardly against the breast to obtain the full de- sired compression. The upward movement of the interface plate functions to distribute and balance the compression and shear forces applied to the breast.

One of the disadvantages of the known mammography- apparatus is that it is still unclear how many compression force must be applied to the breast in order to get proper quality of the subsequent x-ray imaging, without unnecessarily inflicting pain on the patient. A first objective of the invention is to improve the known mammography-apparatus in that unnecessary compression of the breast during x-ray imaging is avoided.

Still a further objective is to enhance the capabil- ity of the mammography-apparatus to reliably detect malignant cells in breast tissue.

These and other objectives of the invention which may become apparent from the following disclosure, are at least in part addressed with the features of the mammography-apparatus of the invention as specified in the appended claims.

In a first aspect of the invention the mammography- apparatus comprises data entry means for inputting an estimated total body volume of the breast and/or an imaging system for the breast which is connected to processing means for es- timating a total body volume of the breast as imaged with the imaging system, and wherein the control system is connected to the data entry means and/or the processing means and arranged to convert the estimated total body volume of the breast into a desired compression force with which the paddle must com- press the breast. This desired compression force which is derived from the total body volume of the breast is then applied to the breast during x-ray imaging.

One of the niceties of the invention is that such an imaging system can be easily provided as an upgrade to an ex- isting mammography apparatus which is still relying on the best efforts of an operator. By upgrading such an existing mammography apparatus with the features according to the invention the advantages that the invention provides will also be available with existing and sometimes very old machines.

The estimation of the total body volume of the breast can effectively be done at home with an app (like Third Love, Tue & co and Adore me) or automatically in the dressing room (3D mirror scans) and subsequently inputted into the system by using the data entry means. Alternatively or additionally the estimation of the breast total body volume can be made by an operator by first applying a moderate compression force to the breast so as to provide the breast in clear focus for the imaging system and to improve the conditions at which an accurate estimation of the breast total body volume can be ob- tained. Once this breast total body volume is known, its value can be used to provide a reliable and repeatable value of the compression force to be subsequently applied to the breast during x-ray imaging so as to secure best x-ray imaging quali- ty.

This procedure follows according to the method of the invention in that after the initial moderate flattening force is applied to the breast, an estimated total body volume of the breast is determined based on an image of the breast ob- tained with an imaging system, and that the estimated total body volume of the breast is thereafter converted into a desired eventual compression force with which the paddle will compress the breast against the x-ray detector during x-ray imaging. As already mentioned the estimated breast total body volume can also be made available to the apparatus by inputting it with data entry means, after the breast total body volume is measured in the privacy of one' s home by an appropriate app, or by automatic means after undressing before the x-ray imaging is executed.

Preferably the control system comprises a look-up table for converting an estimated total body volume of the breast into a desired compression force with which the paddle must compress the breast. Benefits of using a lookup table is that there is a consistent relation between the breast total body volume and the compression force to be applied, and the determination of the desired compression force can be executed swiftly without needing complicated and time-consuming calculations .

Best results in estimating the total body volume of the breast are obtainable when the imaging system comprises a 3D-camera, preferably a CCD camera. Suitably the 3D- camera has a resolution of 1 mm or better.

The invention will hereinafter be further elucidated with reference to the drawing of a mammography-apparatus in accordance with the invention.

In the drawing:

-figure 1 shows schematically the mammography- apparatus of the invention. With reference to figure 1 the mammography-apparatus of the invention is denoted with reference 1. This mammography-apparatus 1 is used for screening malignant cells 8 in a breast 2. For this purpose the mammography-apparatus 1 com- prises an x-ray source 3 and an x-ray detector 4 that cooperates with the x-ray source for providing an x-ray image of said breast 2.

The mammography-apparatus 1 further comprises a paddle 5 for flattening the breast 2 by compressing it against said x-ray detector 4.

The mammography apparatus 1 of the invention further comprises a control system 10 which controls the actuation of the paddle 5 in accordance with a desired compression force F that is to be applied to the breast 2. For determining the de- sired compression force F, the apparatus 1 comprises an imag ^¬ ing system 6 for the breast 2 which is connected to processing means 7 for estimating a total body volume V of the breast 2 as imaged with said imaging system 6.

An alternative which is not shown in the figure be- cause it is entirely clear for the skilled person, is to estimate the breast total body volume by separate means (for instance using an app or otherwise) and to input the estimated total body volume as a number using data entry means, in particular a keyboard, that connects to the control system 10.

The control system 10 is further connected to the processing means 7 and arranged to convert a total body volume V of the breast 2 as estimated with the processing means 7 -or as inputted with the said data entry means- into a desired compression force F with which the paddle 5 must then compress the breast 2 during x-ray imaging. Advantageously therefore the control system 10 comprises a look-up table 9 for converting the estimated total body volume V of the breast 2 into a desired compression force F with which the paddle 5 will compress the breast 2.

Figure 1 further shows for completeness sake that the imaging system 6 preferably comprises a 3D-camera, at best a CCD camera 6' . It is preferable that the 3D-camera has a resolution of 1 mm or better. Although the invention has been discussed in the foregoing with reference to an exemplary embodiment of the apparatus and method of the invention, the invention is not restricted to this particular embodiment which can be varied in many ways without departing from the invention. The discussed exemplary embodiment shall therefore not be used to construe the appended claims strictly in accordance therewith. On the contrary the embodiment is merely intended to explain the wording of the appended claims without intent to limit the claims to this exemplary embodiment. The scope of protection of the invention shall therefore be construed in accordance with the appended claims only, wherein a possible ambiguity in the wording of the claims shall be resolved using this exemplary embodiment .