FAMILY OF BREAST PHANTOMS, GLOBAL PHANTOM, CORRESPONDING MANUFACTURING PROCESS AND ASSOCIATED MOLD

Abstract

The invention relates to a family of breast phantoms (1), at least one of the phantoms being formed from a single solid body, the upper surface of the body being shaped into a dome flaring outwards. The invention relates to an overall phantom, a manufacturing method, and an associated manufacturing mold.

Description

In particular, the family includes at least two so-called "curved" chest phantoms and preferably at least 10 - three 11, 12, 13. Said chest phantoms 11, 12, 13 thus have a shape that is significantly different from that which has been described for the breast phantom 1. In fact, the chest phantoms 11, 12, 13 are here more rounded. 15 one breast ghost of one of these- ghosts of poi trine 11, 12, 13 will now be described. The breast phantom 21 is a physical phantom and comprises a body 22 which is formed from a single element. The body 22 is therefore free of a cavity into which a tampon would be inserted, in particular a tampon made of a material other than the rest of the body 22. The body 22 is substantially shaped into a dome, the base of which forms a lower surface 23 which is intended to rest against a support and the upper surface 24 of which forms the domed part of the dome, the lower surfaces 23 and upper surfaces 24 together forming a closed vol-urn defining the body 22. The body 22 is also solid. The body 22 is thus shaped so as to simulate the curvature of a breast of a human organism, the top of the dome simulating the corresponding nipple. Preferably, the body 22 is devoid of a projecting portion at the location of the nipple. The upper surface 24 of the body 22 is here smooth. The top of the dome is thus located at the level of the corresponding nipple (so as to simulate it) but is not shaped into a nipple strictly speaking. Alternatively, the top of the dome is shaped into a nipple so that the upper surface 24 of the body 22 is not smooth here. The dome drawn by the body 22 is however not of revolution and is not for example ■conically shaped which would not be realistic. On the contrary the dome 22 is irregular. The breast phantom 21 consequently comprises a thinner lateral portion at one end (simulating the attachment of the breast at the sternum), a portion then gradually widening towards the front on the side opposite that of said end. The body 22 is made of a material having X-ray or gamma (y) transmission properties close to those of human tissue. Said material thus reproduces the attenuation properties of the natural breast. The body 22 is here made of polymer material. The body 22 is for example based on polymethyl methacrylate or polycarbonate or even polyurethane. Preferably, the chest phantoms 11, 12, 13 are sized so that they each correspond substantially to a particular cup size. We thus size the chest ghosts 11, 30 12, 13 in order to have a range of -at least one volume similar to cup B at least a similar volume to cup C, and preferably to cup D. This gives us a family that covers the most common breast sizes. The family here comprises a third breast phantom 11 whose volume of each breast phantom is between 300 and 350 cubic centimeters, and preferably between 310 and 330 cubic centimeters, a fourth breast phantom 12 whose volume of each breast phantom is between 520 and 600 cubic centimeters, and preferably between 530 and 590, and a fifth breast phantom 13 whose volume of each breast phantom is between 740 and 830 cubic centimeters, and preferably between 740 and 790 cubic centimeters. The third breast phantom 11 is such that the lower surface area of ​​each breast phantom is between 165 and 190 square centimeters, and preferably between 170 and 180 square centimeters. As previously noted, each breast phantom has a general dome shape that varies in thickness from a maximum thickness substantially at the nipple to a minimum thickness at its lateral ends. The third chest phantom 11 is thus such that said thickness is between 3.2 and 3.6 centimeters, and preferably between 3.35 and 3.45 centimeters. The fourth chest phantom 12 is such that said thickness is between 4.2 and 4.8 centimeters, and preferably between 4.3 and 4.6 centimeters. The fifth 30 chest phantom 13 is such that said thickness is between 5.9 and 6.7 centimeters, and preferably between 6.2 and 6.4 centimeters. We will now focus on comparing the "curved" and "spread out" ghosts. Indeed, from a “spread” breast phantom to a “curved” breast phantom but of the same volume, the shape changes (it being recalled that the two breast phantoms of the same breast phantom are substantially symmetrical). According to a particular embodiment, the dimensions of the upper surface and those of the lower surface of each phantom are different from a “spread” breast phantom to a “curved” breast phantom. Thus, at iso-volume, a "spread" phantom is not only more spread out (so that its lower surface will be larger than those of the lower surface of the "curved" phantom of the same volume) but also flatter than the associated "curved" phantom. Indeed, the chest phantoms 11, 12, 13 are more rounded. So if we look at the breast phantoms from above (facing the nipple), the "curved" breast phantom has a more circular shape than the "spread-out" breast phantom. In the same way, at iso-volume, a "spread out" phantom is such that in use: ti.e. placed on a support in the form of a torso) an axis A passing through the nipple of the phantom and a given point T belonging to a longitudinal axis X along which the sternum extends -, is more inclined, with respect to an anteroposterior axis Y passing 30 by said given point T of the sternum than for a “curved” phantom. Thus, according to a particular embodiment, the angle formed by the nipple-given point axis A of the sternum: and the anteroposterior axis Y is between 60 and 76 degrees for a "curved" phantom and preferably between 64 and 75 degrees. The angle α formed by the nipple-given point axis A of the sternum and the anteroposterior axis Y is between 16 degrees (not included) and 95 degrees for a "spread" phantom and preferably between 77 and 90 degrees. Furthermore, the thickness -along- an axis (parallel to: the antero-posterior Y axis) passing through the center of gravity of the body is identical between a "curved" phantom and a "spread-out" phantom for the same volume. The family of chest ghosts includes chest ghosts of different volume and chest ghosts of varying spread. So here we have the following family: Model Name Corresponding Size Ghost Shape il B Curved 12 i Curved 13 D Curved 14 c Spread- 15 D Spread Table 1 Note that at least for the smallest volume of "curved" phantom, we do not create a "spread" phantom of corresponding volume. The inventors were in fact able to observe that for small volumes, the difference in shape between "curved" and "spread out" had little or no influence on the sampling. 5 Multiple reference measurements can thus be carried out Advantageously, each chest phantom is more representative of a human organism of a particular class - allowing for better reference measurements to be obtained using said phantom. 10' We thus offer the clinician a wide choice for calibration using different phantoms depending on different breast sizes and more or less significant sagging. Moreover, advantageously, in the event of strong asymmetry of a particular patient's breast, it is possible for a practitioner to dissociate the breast phantoms between two different breast phantoms in order to make the whole as representative as possible. With reference to Figure 3, the family is intended 20 to be placed on a torso phantom 20 serving as a support. The torso phantom associated with a chest phantom - jointly form a global phantom. ■The chest phantoms are here simply placed on the torso phantom 20, the latter being stretched out for 25 the -examinations. The breast phantoms are here arranged on the torso phantom 20 such that each breast phantom extends between substantially the first and fifth ribs of the torso phantom 20. 30 This allows for a particular torso phantom 20- 1stly realistic. Preferably, the torso phantom 20 and the chest phantoms are shaped to facilitate retention of the chest phantoms on the torso phantom 20. In this case, the lower surfaces of the 5 chest phantoms -are shaped- to fit the shape of the torso phantom area 20 on which the chest phantoms rest. Since the dome bases of the different family phantoms are not flat. According to a particular embodiment, the ghost 10 of torso 20 is a ghost already existing on the market as a torso ghost called "Livermore". With reference to Figure A, the method of manufacturing a breast phantom of the family previously described will now be detailed. 15 The first step 101 is to create a model ■3D digital raw of the breast phantom body. For this purpose, we rely here on patient scans in order to establish a model of a volume and a pro- 20 threads ("spread-" or "curved") given-. For example, we define a first model from a single scanner (by delineating the contours) and we modify the dimensions of said model from scanners of patients with a breast of similar volume and / or shape. 25 According to a second step 102, we model the - -phantom of torso on which we wish to position the phantom of ■breast. Typically, an existing physical torso phantom is scanned and then a digital three-dimensional model of the torso phantom is generated. During a third step 103, the raw model of the breast phantom is adapted to the model of the torso phantom in order to obtain an adapted model of the breast phantom. To this end, the raw model of the breast phantom 5 is positioned on the torso phantom model at the level of the tone of said model corresponding to the area where the physical breast phantom is to be placed in service. Qn adapts the shape of the lower surface of the body accordingly so that the adapted model of the breast phantom fits the surface opposite the model of the torso phantom. □h then ensures that the volume of the adapted breast phantom model still corresponds substantially to the target volume despite this adaptation. Otherwise, the outer surface is modified accordingly, By "substantially" is meant, within a tolerance, a tolerance which is less, in absolute value, than 6% and preferably less than 5% and even more preferably less than 1% of the target volume. 20 The fourth step 104 is to make the fan chest tom-. This is done, for example, by additive manufacturing using a 3D printer and the adapted model of a breast -phantom-, 25 In this case a -fifth- step 105 consists of net to clean the ghost of -breast. In this way, a breast phantom with high reproducibility is obtained. -According to a variant of the fourth step 104 described 30 above, the phantom is manufactured by molding. In a first level 106, the associated mold 30 is digitally modeled from the adapted breast phantom model. during a second stage, the mold 30 is manufactured for example by additive manufacturing, by injection ... The mold 30 can thus be made of metallic material as well as polymer material, plastic material ... As illustrated in Figure 5, the mold 30 comprises a first physical part 31a and a second physical part 31b delimiting -between- them- an imprint 33 of the breast phantom. The first part 31a is here the upper part, that is to say the part not resting on the support during molding. Typically, the mold 30 has a generally cubic or rectangular parallelepiped shape. The mold 30 here has two main faces 32a, 32b (one 32b being the one intended to rest on a support and the other 32a being the opposite face). The two main faces 32a, 32b are here square in shape. The imprint 33 is thus formed in the mold 30 so that it is the first part 31a which delimits the curved part of the imprint 33 corresponding to the zone around the nipple and so that it is the second part 32b which delimits the lateral ends of the imprint 33 and in particular the thin attachment end at the level of the sternum. According to a preferred embodiment, the first part 31a thus comprises a larger volume of 30 1st imprint 33 that the part 31a second part 31b. Typically comprises between 55 and 80% of the volume total of the imprint 33 and preferably between 59 and 70% of the total volume of the imprint 33. For this purpose, the first part 31a does not have the same thickness here (along an axis A normal to the 5 main faces 31 of the mold) as the second part 32b. The thickness of the first part 31a is thus 1.2 to 2.5 times greater than that of the second part 31b. This makes it easier to unmold the breast ghost. 10 Similarly, the imprint 33 is made in the mold 30 so that the two lateral ends of the impression 33 end in the same plane, a plane which is parallel to the two main faces 32 a, 32 b of the mold. This makes it even easier to remove the breast phantom from the mold. Preferably, the two parts 31a, 31b are fixed together temporarily, for example by screwing. For this purpose, the two parts 31a, 31b have holes 34 (only one part being referenced 20 here) opposite each other to allow the passage of screws. Typically, the two parts 31a, 31b have between four and eight sets of holes for screwing. Preferably, the two parts 31a, 31b further comprise interlocking and / or snap-fastening means. 25 This helps to promote sealing between the two parts 31a, 31b and to facilitate their relative positioning. Here one of the parts 31b comprises pegs 35: which fit into holes opposite the other part 30, 31a. Typically, both parts 31a, 31b comprise between four and eight dowel-hole sets. Furthermore, the first part 31a comprises an orifice 36 passing through said part 31a from the outside until it reaches the imprint 33. The orifice 36 is for example shaped like a truncated cone. Said orifice 36 is here arranged so as to extend along a normal to the main faces 32a, 32b, i.e. substantially vertically. Preferably, said orifice 36 is arranged so as to open at the level of the nipple and / or the zone 10 of maximum thickness of the impression 33. During the fourth step 104, the mold 30 is filled via the filling orifice 36 and then the material is allowed to harden before demolding. During a fifth step 105, the phantom is possibly cleaned. If necessary, the breast phantom can be smoothed at the level where the material was poured (at the filling orifice 36) or on its edges. The invention is not limited to what has just been described, but on the contrary encompasses any variant falling within the scope defined by the claims. Thus, although here the torso phantom is the same for a whole family of breast phantoms, the family of breast phantoms could be associated with a family of torso phantoms for example of different dimensions in terms of chest circumference. Although the torso phantom already exists here, we can of course create the torso phantom directly. 30 Moreover, although here the ghosts of breast are simply placed on the torso ghost, the fan- 10 15 20 25 30 Chest tomes can be attached to the torso phantom, preferably temporarily in order to be able to interchange the chest phantoms more easily. For example, the chest phantoms will be temporarily attached by hinge, by interlocking, by textile attachment, etc. to the torso phantom. The different phantoms may be different from what has been described. For example, although here the two breast phantoms of a chest phantom are two independent elements, the two breast phantoms may be permanently linked together (by gluing, by screwing, by being in one piece) or be temporarily linked together (by snapping, by fitting together). Breast ghosts may not be grouped into chest ghosts. The family may also include a different number of ghosts than indicated. For example, the family may include a greater number of ghosts. Thus, the family can include at least five chest ghosts of different sizes - and preferably at least seven. Preferably, the breast phantoms will be sized so that each one corresponds approximately to a particular cup size. The chest phantoms will be sized to have a range from at least a volume similar to an A cup to at least a volume similar to an E cup, and preferably to a G cup. The family will include here: a first breast phantom, the volume of each breast phantom of which is between 100 and 200 cubic centimeters, and preferably between 120 and 170 cubic centimeters, a second breast phantom, the volume of each breast phantom being between 300 and 350 cubic centimeters, and preferably between 310 and 330 cubic centimeters, a third breast phantom, the volume of each breast phantom being between 520 and 600 cubic centimeters, and preferably between 530 and 590, a fourth breast phantom - the volume of each breast phantom being between 740 and 830 cubic centimeters, and preferably between 740 and 790 cubic centimeters, a fifth breast phantom, the volume of each breast phantom being between 850 and 1000 cubic centimeters, and preferably between 855 and 950 cubic centimeters, a sixth breast phantom, the volume of each breast phantom of which is between 1000 and 1100 cubic centimeters, and preferably between 1020 and 1070 cubic centimeters, a seventh breast phantom, the volume of each breast phantom being between 1150 and 1250 cubic centimeters, and preferably between 1170 and 1220 cubic centimeters. Furthermore, the family may include iso-volumes, a greater number of chest phantoms of different spread than the two described (a "curved" phantom and a "spread" phantom). Furthermore, the family may include a greater number of "spreading" chest ghosts associated with "curvy" ghosts than indicated. Thus, the family may include at least three chest ghosts "spread out" of different volumes and preferably at least five. Preferably, the "spread" chest phantoms will be sized so that each one roughly corresponds to a particular cup size. The "spread" breast phantoms will be sized to have a range from at least a volume similar to a G cup to at least a volume similar to that of an E cup and preferably to that of a G cup. The family will include here: a first “spread” breast phantom whose volume of each breast phantom is between 520 and 600 cubic centimeters, and preferably between 530 and 590, a second "spread out" breast phantom whose volume of each breast phantom is between 740 and 830 cubic centimeters, and preferably between 740 and 790 cubic centimeters, a third - breast phantom - "spreads out" whose volume of Each breast phantom is between 850 and 1000 cubic centimeters -, and preferably between 855 and -950 cubic centimeters, a fourth "spread-out" breast phantom whose volume of each breast phantom is between 30 1000 and 1100 cubic centimeters and preferably between 1020 and 1070 cubic centimeters a fifth "spread" breast phantom with the volume of each breast phantom between 1150 and 1250 cubic centimeters, and preferably between 1170 and 1220 cubic centimeters. We can thus have the following family: Model Name Corresponding Size Phantom Shape 1 A Curved 2 B Curved 3 C Curved 4 D Curved 5 E Curved 6 F Curved 7 G Curved 3 bis C: Spread 4 bis D Spread 5 'bis E Spread 6 bis F Spread 7 bis G Spread Table- 2 For at least the two smallest volumes of "curved" phantom, a "spread" phantom of corresponding volume will not be created.

Claims

CLAIMS 1, Family of corner phantoms comprising at the fist; two breast phantoms, each phantom being formed of a single solid body, the two bodies having a volume without the same mark and being of different shape, an upper surface of one of the two bodies being shaped into a dome flaring further outwards making it possible to define a first phantom called "spread out" more flared than the phantom cave; called "curved".

2. A family of phantoms according to claim 1, wherein the lower surface (3; of at least one of the bodies is shaped to fit the shape of a cone of a torso phantom on which the breast phantom is tilted to rest.

3. A family of phantoms according to claim 1 or claim 2, comprising at least one third breast phantom of a different volume from the other two breast phantoms, the third breast phantom being formed from a single solid body, an upper surface of the body being shaped into an outwardly flaring.

4. Family of phantoms according to one of claims 1 to 3, comprising, for each breast phantom of the family of phantoms, a similar breast phantom so that the phantoms form two by two a breast phantom (11, 13, 13, 14, 15).

5. Family of phantoms according to one of claims 1 to 4, in which at iso-volume, the "spread-out" phantom is such that in use an axis passing through a nipple of said phantom and a given point belonging to a longitudinal axis is more inclined with respect to an axis

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