NL2009856C2

NL2009856C2 - Mammography apparatus.

Info

Publication number: NL2009856C2
Application number: NL2009856A
Authority: NL
Inventors: Gerard Johan Heeten; Cornelis Antonius Grimbergen
Original assignee: Amc Amsterdam
Priority date: 2012-11-21
Filing date: 2012-11-21
Publication date: 2014-05-27

Description

Mammography apparatus

The invention relates to a mammography apparatus comprising a frame supporting an x-ray source, a paddle and a de-5 tector with a detector cover for detecting malignant cells in a patient's breast, wherein the paddle and the detector cover compress the breast prior to and during monitoring of the breast.

W02011/102713 discloses a mammography apparatus com-10 prising an x-ray source, a paddle and a detector with a detector cover. The known mammography apparatus comprises a mainframe that supports a subframe in which the x-ray source, the paddle and the detector are mounted. In such a known mammography apparatus it is day to day practice to place and compress 15 a patient's breast between the detector and the paddle before executing an x-ray measurement in order to optimize the image quality and minimize the required x-ray doses. During the procedure the patient is standing next to the mammograph. The compression is applied by bringing the patient's breast in be-20 tween the x-ray detector and the paddle, which paddle can thereafter be lowered in the direction and relative to the detector by hand or by activating a motor built in the mammography apparatus .

It is an objective of the invention to improve the 25 reliability and repeatability of the x-ray measurement by providing a more reliable positioning and compression of the breast.

It is still another objective of the invention to provide an improved mammography apparatus which ensures that 30 the objective of a more reliable and repeatable x-ray measurements can be achieved.

It is a further objective of the invention to enhance the immobilisation of the breast during mammography and in other circumstances where flattening of the breast can be mod-35 est like in tomosynthesis.

These and other objectives of the invention which will become apparent from the following disclosure, are attained with the mammography apparatus according to one or more 2 of the appended claims.

According to a first aspect of the invention the paddle and/or the detector cover are provided with a rough surface on the side that in use contacts the patient's breast 5 skin to secure positioning of the breast between the paddle and the detector cover for compression and monitoring. The positioning of the breast is normally assisted by a paramedic and is in the prior art device suffering from inaccuracy caused by the tendency of the breast to escape from the space 10 between the paddle and the detector cover, particularly during compressing of the breast.

There are several usable ways to provide the paddle and/or detector cover with the required rough surface. Suitably the rough surface is embodied as an x-ray transparent 15 coating. In another embodiment however the rough surface is provided by surface treatment of the paddle and/or the detector cover, for instance by electrochemical etching or mechanical profiling.

Beneficially the rough surface is embodied as a su-20 perficial saw tooth corresponding to the resolution of the x-ray imaging of the breast, that is less than about 50 pm. This will provide optimal imaging results.

Although it is possible to achieve the benefits of the invention with a rough surface providing isotropic fric-25 tion, there is preference that the rough surface provides anisotropic friction, such that the friction is lower when the breast moves towards the frame than when the breast moves away from the frame. This solution is sufficient for acquiring a cranio-caudal (CC) view. The lower friction when the breast 30 moves towards the frame further promotes easy placing and positioning of the breast immediately prior to its monitoring.

In acquiring a medio-lateral-oblique (MLO) view, there is an additional sideways effect of gravity making it useful to have an anisotropic friction such that the friction 35 is higher when the breast tends to move sideways. This is beneficial not only for preventing a motion away from the frame but also a sideways motion. As this direction is different for a right and a left MLO compression, it is beneficial to adapt the direction of the anisotropic friction in the different 3 quadrants of the surface of the paddle and the detector cover.

In another embodiment the paddle and/or the detector cover are provided with a smooth vertical surface that in use faces a patient being monitored. This smooth vertical surface 5 restricts shear reaction forces between the mammography apparatus and the skin of the patient. It is found that for an optimal compression of the breast, the reaction forces between the mammography apparatus and the patient should be minimized as reaction forces are at the expense of the forces available 10 for flattening of the breast tissue and may lead to undesirable stretching of the skin that may cause additional pain during the measurement procedure.

The invention will hereinafter be further elucidated with reference to a schematic drawing.

15 The drawing shows in figure 1 a patient standing next to a mammography apparatus according to the invention, and in figure 2 a cross-section of the paddle and/or detector cover of the mammography apparatus of the invention.

Whenever the same reference numerals are applied, 20 these numerals refer to the same parts.

The mammography apparatus of the invention is generally denoted with reference 1. This mammography apparatus 1 has a mainframe 1' that is provided with an x-ray source 2, a paddle 3 and a detector 4 with a detector cover 5 that con-25 tacts the underside of a patient's breast 6. The person skilled in the art is aware that the x-ray source 2, the paddle 3 and the detector 4 are placed on a subframe 1'' (also called c-arm) that is mounted in the mainframe 1'.

According to the invention the paddle 3 and/or the 30 detector cover 5 are provided with a rough surface on the side that in use contacts the patient's breast 6 skin to secure positioning of the breast 6 between the paddle 3 and the detector cover 5. Beneficially the rough surface is embodied as an x-ray transparent coating. Alternatively the rough surface is 35 provided by surface treatment of the paddle 3 and/or the detector cover 5.

Preferably the rough surface is embodied as a superficial saw tooth with an amplitude corresponding to the resolution of the x-ray imaging of the breast, that is less than 4 about 50 pm, an example of which is shown in figure 2. This figure 2 shows a cross-section of the paddle 3 or alternatively a cross-section of the detector cover 5.

In a preferred embodiment the rough surface provides 5 anisotropic friction, such that the friction is lower when the breast 6 moves towards the frame 1', 1'' than when the breast 6 moves away from the frame 1', 1''.

It is beneficial to provide the paddle 3 and/or the detector cover 5 on their frontal parts 3', 5' with surface 10 material that reduces friction with the patient's skin. For this purpose the paddle 3 and/or the detector cover 5 are provided with a smooth vertical surface 3', 5' that in use contacts a patient being monitored. This helps reducing pain sensations caused by mechanical shear loading of the skin.

Claims

Mammography device (1) comprising a frame (1 ', 1' ') carrying an X-ray source (2), a paddle (3) and a detector (4) with a detector housing (5) for detecting malignant cells in a breast (6) of a patient, in which the paddle (3) and the detector housing (5) compress the breast (6) before and during taking a picture of the breast (6), characterized in that the The paddle (3) and / or the detector housing (5) are provided with a rough surface on the side in contact with the skin of the patient's breast (6) to ensure positioning of the breast (6) between the paddle (3) and the detector housing (5).

Mammography device according to claim 1, characterized in that the rough surface is designed as a coating that is transparent to X-rays.

Mammography device according to claim 1, characterized in that the rough surface is provided by surface treatment of the paddle (3) and / or the detector housing (5).

Mammography device according to one of the preceding claims, characterized in that the rough surface is designed as a sawtooth arranged on the surface with an amplitude corresponding to the resolution of the X-ray imaging of the breast, preferably less than about 50 μπι.

Mammography device according to one of the preceding claims, characterized in that the rough surface provides anisotropic friction.

Mammography device according to one of the preceding claims, characterized in that the rough surface provides anisotropic friction such that the friction is lower when the breast (6) moves towards the frame (1 ', 1' ') than when the chest (6) moves away from the frame (1 ', 1' ').

Mammography apparatus according to claim 5 or 6, 35, characterized in that the rough surface provides anisotropic friction such that the friction is higher when the breast tends to move sideways.

Mammography device according to one of the preceding claims, characterized in that the paddle (3) and / or the detector housing (5) are provided with a smooth vertical surface (3 ', 5') which, in use, is in contact with a patient from whom a recording is made.