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Breast Implant Classification with MR Imaging Correlation¹

(CME available on RSNA Link)

¹ From the Department of Radiology, 410 Dickinson St, San Diego, CA 92103-8749 (M.S.M.) and Case Western Reserve University, Breast Imaging Center MetroHealth Medical Center, 2500 MetroHealth Dr, Cleveland, OH 44109-1998 (M.P.M.). Received July 8, 1999; revision requested December 13; revision received and accepted December 21.

View larger version (151K): [in a new window]   Figure 1. Ligation valve. Style 1400 Heyer-Schulte Tabari saline-filled implant (placed 1972) with a ligation valve seen here pulled out of the pocket in which it can be buried (photographed upside down). A narrow strip of Dacron mesh-reinforced elastomer is present around the entire circumference of the implant inside the implant shell. Two crescent-shaped strips (arrows) of Dacron felt fixation material are present on the posterior superior part of the implant, with some ingrown tissue still attached (143,144).

View larger version (97K): [in a new window]   Figure 2. Tube valve. Roger Klein saline-filled implant (placed 1974), originally designed by Dr H. G. Arion (98), imported into the United States by Roger Klein. (New York, NY) from Simaplast (Paris, France) as the Arion implant, and later manufactured by Roger Klein as the Mammatech implant (123,124). These implants had a circumferential seam and a tube protruding from the implant that could be stoppered, inverted into the implant, or both. The valve could be at the side (thin arrow), on the anterior surface, or on the posterior surface of the implant. A large round shell patch is shown here on the posterior surface of the implant (thick arrow). This type of valve has a characteristic appearance at mammography (Fig 3) and probably also on MR images.

View larger version (128K): [in a new window]   Figure 3. Tube valve. Xeromammogram of the Roger Klein saline-filled implant shown in Figure 2, showing the plug valve inverted into the implant and the large round back patch.

View larger version (100K): [in a new window]   Figure 4. Plug valve. One early Surgitek implant, known as the Dahl implant, was inflated with silicone at time of placement (115). Shown here is the "plug valve" of such an implant placed in about April 1975, stoppered with a white plug. The inner edge of the hole in the shell is just discernible. Free gel is present on the implant surface. This type of valve should have a characteristic and identifiable cylindric appearance on MR images.

View larger version (110K): [in a new window]   Figure 5. Plug valve. Shown here is an early Koken implant, which we understand also was known as the Akiyama implant13 , with a plug valve (82). The plug (arrow) is removable, rivet-shaped (or mushroom-shaped), and placed directly into the implant shell hole. The Dacron mesh used to provide fixation for this implant, remnants of which are seen here, has a rather coarse rectangular weave pattern. It is our understanding that this implant was placed in 1980. This type of valve may have a characteristic appearance on MR images.

View larger version (126K): [in a new window]   Figure 6. Seal-Seal inflatable (SSI) valve. Xeromammogram of an early Surgitek saline-filled implant (placed 1974). Both the SSI valve (thin arrow) and the implant back patch (thick arrow), on the posterior surface of the implant, are evident.

View larger version (138K): [in a new window]   Figure 7. Seal-Seal inflatable (SSI) valve. Surgitek Georgiade contoured standard double-lumen implant (placed 1978), showing the Dacron mesh-reinforced SSI valve (arrow), containing a fairly thick silicone gel, mounted on the inner surface of the back patch on the outer posterior shell. This type of valve also can be found mounted directly on the internal surface of the outer shell of other Surgitek standard double-lumen implants, and is the same type of valve that was used in some Surgitek saline-filled and gel-saline implants in the 1970s and early 1980s. This type of valve has a characteristic appearance on MR images (Fig 8).

View larger version (128K): [in a new window]   Figure 8. Seal-Seal inflatable (SSI) valve. Sagittal T2-weighted fast spin-echo water-suppressed MR image showing the SSI valve in a round (ruptured) Surgitek Munna standard double-lumen implant (placed 1982). The signal from the silicone in the SSI valve (long arrow) is not as bright as the signal from the silicone gel in the inner (and outer) lumen most likely for two reasons: It is more highly crosslinked, and it is likely that there is suppressed waterlike fluid intermixed with the silicone gel. The presence of silicone outside the (outer shell) SSI valve (short arrow) is a definitive sign that the implant is ruptured. This type of fill-port is shown in Figure 7 on a different style of Surgitek standard double-lumen implant.

View larger version (107K): [in a new window]   Figure 9. Leaflet valve. Posterior surface of a Surgitek 22000 series round standard double-lumen implant (placed 1983), with the characteristic small white 3-mm dot (thin arrow) with a slit, proximally marking one end of the fill channel. The rectangular leaflet valve, measuring about 10 x 60 mm, is seen here extending to the left (thick arrow). Rarely seen MR images capturing the appearance of this type of leaflet valve are shown in Figures 10 and 11.

View larger version (78K): [in a new window]   Figure 10. Leaflet valve. T2-weighted fast spin-echo silicone-suppressed MR image (original magnification, x5) of the distal part of the leaflet valve of a Surgitek standard double-lumen implant such as that shown in Figure 9, showing the characteristic appearance of the leaflet valve in cross section. (This cross section is what would be seen at about the location of the thick arrow in Figure 9). In this image the inner-lumen silicone gel is dark and the outer-lumen saline surrounding the leaflet valve is bright. Another more distal (en face) MR cross section through this same type of valve is shown in Figure 11.

View larger version (94K): [in a new window]   Figure 11. Leaflet valve. T2-weighted fast spin-echo silicone-suppressed MR image (original magnification, x5) of the distal part of the same type of leaflet valve shown in Figures 9 and 10, showing its characteristic squared-off appearance en face. In this image the inner-lumen silicone gel is dark and the outer-lumen saline surrounding the leaflet valve is bright.

View larger version (92K): [in a new window]   Figure 12. Leaflet valve. Posterior surface of a Dow Corning 380 series standard double-lumen implant (placed 1985), showing the most common configuration for the leaflet valve for this series (thick arrow). Just barely visible on this implant itself (but not in this photograph) were the markings "SILASTIC II 300 cc" on the round inner-lumen back patch (thin arrow). The xeromammographic appearance of this implant is shown in Figure 13, and the characteristic MR imaging appearance of this type of leaflet valve is shown in Figure 14.

View larger version (108K): [in a new window]   Figure 13. Leaflet valve. The appearance of the distal part of the leaflet valve for the Dow Corning 380 series standard double-lumen implant shown in Figure 12 is demonstrated on this xeromammogram (arrow). The characteristic xeromammographic appearance of saline present in the outer lumen of the standard double-lumen implant is also shown here (a). The characteristic appearance of this type of leaflet valve on MR images is shown in Figure 14.

View larger version (118K): [in a new window]   Figure 14. Leaflet valve. T2-weighted silicone-suppressed MR image of the distal part of the leaflet valve in a Dow Corning 380 series standard double-lumen implant, showing the en face MR imaging appearance of the type of leaflet valve illustrated in Figures 12 and 13.

View larger version (101K): [in a new window]   Figure 15. Leaflet valve. Surgitek reverse-adjustable double-lumen implant (placed 1985). Beveled back patch outside implant shell is shown here (thick arrow) with two gel fill points (short arrows), one for each silicone gel-filled lumen. Toward the center of the back patch is the 3-mm white dot and slit (long arrow) marking the entry point to the short Quin-Seal leaflet valve leading to the inner lumen. (The slit is not discernible on this photograph.) The MR imaging appearance of this implant is illustrated in Figures 58 and 59.

View larger version (80K): [in a new window]   Figure 16. Double leaflet valve. Mentor Becker 25/75 reverse double-lumen implant with a double leaflet valve, one for the inner and one for the outer shell (placed 1986). The fill tube has been withdrawn from this implant, and so both leaflet valves have curled (arrows), giving a "window-shade" appearance. This type of curled window shade appearance can be seen on some MR images. This type of implant also was manufactured with one curled (inner) and one flat (outer) leaflet valve.

View larger version (101K): [in a new window]   Figure 17. Retention valve. Heyer-Schulte Style 1200 saline-filled breast implant with a retention valve (placed 1976). The valve has a round narrow proximal part (short arrow) and a flat distal part (thick arrow), and is attached to the implant shell through a round patch (long arrow). The cross-sectional MR imaging appearance of this type of valve is shown in Figures 18 and 19.

View larger version (81K): [in a new window]   Figure 18. Retention valve. T2-weighted fast spin-echo silicone-suppressed MR image of Heyer-Schulte Style 1200 (or 1300) saline-filled breast implant with a retention valve, showing a cross section through the proximal round neck of the valve (short arrow). A peripheral fold is also seen (long arrow). A photograph of a valve of this type is shown in Figure 17, and the MR imaging appearance of the distal flat part of this valve is shown in Figure 19.

View larger version (76K): [in a new window]   Figure 19. Retention valve. T2-weighted fast spin-echo silicone-suppressed MR image of Heyer-Schulte Style 1200 (or 1300) saline-filled breast implant with a retention valve, showing a cross section through the distal flat part of the valve (short arrow). The peripheral fold is also seen (long arrow). A photograph of a valve of this type is shown in Figure 17, and the MR imaging appearance of the proximal round part of this valve is shown in Figure 18.

View larger version (100K): [in a new window]   Figure 20. Retention valve. Heyer-Schulte Style 7000 Hartley-type standard double-lumen breast implant (late version with slit in shell patch, placed 1982), showing the retention valve (a) on the posterior shell adjacent to the central back patch (b). The valve is attached to the shell through an elastomer disk (c). The opening to the valve (d) is placed just under the slit in that disk. The MR imaging appearance of this type of implant is shown in Figure 21.

View larger version (90K): [in a new window]   Figure 21. Retention valve. Axial T2-weighted silicone-suppressed MR image of Heyer-Schulte standard double-lumen implant with a retention valve (placed 1983). This MR image illustrates the slightly curled (thickened) edges of the distal flat part of the valve (arrow). A photograph of this type of implant is shown in Figure 20.

View larger version (107K): [in a new window]   Figure 22. Diaphragm valve. Style 1600 Heyer-Schulte saline-filled implant (placed 1982), showing the anterior diaphragm valve (thin arrow) with a strap (thick arrow) and attached central plug, bonded to the implant shell on both sides. The MR imaging appearance of this type of valve is shown in Figure 24. Earlier saline-filled implants from this manufacturer had a larger so-called Jenny valve, named after Dr Henry Jenny, who was the first to design saline implants, in 1968, with a diaphragm valve14 . Those earlier implants had a plug attached to the shell with a strap on only one side.

View larger version (71K): [in a new window]   Figure 23. Back patch of Heyer-Schulte Style 1600 implant. Same Heyer-Schulte implant as shown in Figure 22, showing the posteriorly placed back patch and annulus inside the implant shell, with an "M" on the overlap portion of the shell and the back patch (arrow). The back patch on saline-filled implants such as this are necessary to close the shell hole remaining after the shell is formed on a mandrel. These patches can sometimes be seen at mammography, and also on MR images (Fig 24).

View larger version (81K): [in a new window]   Figure 24. Diaphragm valve. Axial T2-weighted fast spin-echo silicone-suppressed MR image of a Style 1600 Heyer-Schulte saline-filled implant (placed 1983) showing the diaphragm valve and back patch. The usually anterior-facing diaphragm valve is posterior here (thin arrow), and the usually posterior-facing back patch is seen anteriorly (thick arrow). (This implant position is occasionally seen and does not have any clinical or cosmetic significance.) Photographs of the type of diaphragm valve and back patch used on this kind of implant are shown in Figures 22 and 23.

View larger version (72K): [in a new window]   Figure 25. Internal tube valve. Sagittal T2-weighted fast spin-echo water-suppressed MR image of a Mentor Becker Siltex (textured) reverse double-lumen implant (placed 1991), with bright(er) outer-lumen silicone gel (a) and dark inner-lumen saline (b), showing portions of the posterior valve assembly (arrow). These were available in a 50/50 or a 25/75 gel-to-saline ratio. The appearance of this implant with silicone-suppression MR imaging is shown in Figure 26.

View larger version (81K): [in a new window]   Figure 26. Internal tube valve. Sagittal T2-weighted fast spin-echo silicone-suppressed MR image (same section as in Fig 25) of a Mentor Becker Siltex (textured) reverse double-lumen implant, with dark outer-lumen silicone gel (a) and bright inner-lumen saline (b). Bright intracapsular waterlike fluid is seen surrounding the implant (c), a common finding for implants with a textured surface.

View larger version (106K): [in a new window]   Figure 27. Four-quadrant fixation patches. Dow Corning 830 series implant showing the four-quadrant fixation patch design (placed 1965). The outer layer of loose Dacron mesh has been cut from each of the Dacron mesh-reinforced elastomer fixation patches. Seen here are the cut sutures that originally joined those two layers (thin arrow). Those sutures compartmentalize the fixation patches, producing a characteristic "zebra-stripe" appearance on MR images (Fig 28). The posterior surface of the implant is shown here, photographed from the side. Most early versions of the 830 series implants, such as this one, have a non-everted peripheral seam (thick arrow); later versions have an everted peripheral seam.

View larger version (104K): [in a new window]   Figure 28. Four-quadrant fixation patches. Sagittal T2-weighted fast spin-echo water-suppressed MR image of a Dow Corning 830 series implant (single-lumen silicone gel-filled, placed 1965) (Fig 27), showing its characteristic four-quadrant Dacron mesh-backed fixation patches. On water-suppressed MR images this type of fixation patch has a "zebra-stripe" appearance (thick arrows). This implant is in a state of uncollapsed rupture, as evidenced by the "keyhole" (short arrows) and "pull-away" (long arrow) appearances peripherally (4), confirmed at surgery.

View larger version (127K): [in a new window]   Figure 29. Dow Corning 530 series fixation patches. Posterior surface of a contoured Dow Corning 530 FP series implant (placed 1970, not ruptured) showing the dumbbell-shaped inferior Dacron mesh fixation patch and three additional fixation disks bonded directly to the implant shell. Each patch consists of a layer of loose Dacron mesh, which is sewn to a layer of Dacron mesh-reinforced elastomer. The outer mesh layer has been cut away from this implant and is not shown here. Portions of it with ingrown tissue are shown in Figure 30. The dumbell-shaped patch overlies two shell holes separated by a slit (not shown here). This was the first "seamless" style of Dow Corning implant. The fixation patches can often be seen on MR images, depending on the imaging protocol used (Fig 31).

View larger version (127K): [in a new window]   Figure 30. Dow Corning 530 series fixation patches. Shown here are portions of the outer Dacron mesh layer that were dissected from the fixation patches at the time of explantation, for the Dow Corning 530 FP series implant (placed 1970) shown in Figure 29. Tissue has grown directly into the Dacron mesh layer of these fixation patches. The fixation patches can often be seen on MR images, depending on the imaging protocol used (Fig 31).

View larger version (98K): [in a new window]   Figure 31. Dow Corning 530 series fixation patches. Axial T2-weighted fast spin-echo water-suppressed MR image of the Dow Corning 530 FP series implant (placed 1970) shown in Figures 29 and 30, with the "dumbbell plus 3 round disk" pattern of fixation patches, showing no evidence of rupture. This image shows a cross section through the upper part of the "dumbbell." The fixation patches (arrows) can appear solid, as shown here, or can have the zebra-stripe appearance seen in Figure 28.

View larger version (134K): [in a new window]   Figure 32a. Dow Corning 900 series fixation patches. In about 1973, a new pattern of fixation disks was introduced by Dow Corning in which the outer Dacron mesh layer was embedded into the elastomer disk in a pleated fashion rather than sewn into it. These implants had two, three, or four such round fixation disks bonded to their posterior surface, one of which was over the shell hole, usually with a separate back patch (thick arrow) and reinforcement disk (not shown here) inside the shell hole (see Figs 48 and 49). Shown here is an example of this method of fixation on a catalogue no. 965 Dow Corning implant with four fixation disks, placed in 1975. The mandrel marking "5" is faintly seen centrally (thin arrow) in a (close-up view shown in b), about 4 mm in height, indicating the implant size.

View larger version (128K): [in a new window]   Figure 32b. Dow Corning 900 series fixation patches. In about 1973, a new pattern of fixation disks was introduced by Dow Corning in which the outer Dacron mesh layer was embedded into the elastomer disk in a pleated fashion rather than sewn into it. These implants had two, three, or four such round fixation disks bonded to their posterior surface, one of which was over the shell hole, usually with a separate back patch (thick arrow) and reinforcement disk (not shown here) inside the shell hole (see Figs 48 and 49). Shown here is an example of this method of fixation on a catalogue no. 965 Dow Corning implant with four fixation disks, placed in 1975. The mandrel marking "5" is faintly seen centrally (thin arrow) in a (close-up view shown in b), about 4 mm in height, indicating the implant size.

View larger version (98K): [in a new window]   Figure 33. Dow Corning 580 series fixation patches. Axial T2-weighted fast spin-echo water-suppressed MR image of the same type but an earlier style of implant than is shown in Figure 32. The four round fixation disks on this implant are thinner than the older four-quadrant patches, and so the "zebra" pattern is rarely if ever seen. This Dow Corning implant, placed in 1973, was intact, confirmed at surgery. The appearance of silicone outside the implant shell posteriorly on this MR image (arrow) is probably due to the presence of a small amount of silicone fluid (not gel) between the layers of one of the fixation disks. This was one our false-positive findings.

View larger version (124K): [in a new window]   Figure 34. Fenestration-style fixation patch. Some of the early McGhan and McGhan/3M nonround implants, such as this standard double-lumen implant placed in 1980, had an octagonal-shaped fenestration-style fixation device (a) attached to the back patch (b). It consisted of a thin sheet of silicone elastomer with numerous small holes into which tissue was meant to grow. This was called the "silicone fixation option" by the manufacturer(s). Also shown is a Dacron mesh-reinforced elastomer "keyhole"- (or "paddle"-) shaped suture tag (c), such as was used on some McGhan and McGhan/3M implants (Fig 42), a second shell patch (d) for the leaflet valve, and the leaflet fill valve itself (e). These fenestration-style fixation patches will rarely, if ever, be discernible on MR images.

View larger version (129K): [in a new window]   Figure 35. Fenestration-style fixation patches. Early Heyer-Schulte Style 2000 single-lumen silicone gel-filled implant, placed in 1972, with "double hemicircle" fenestration-style fixation patches (a and b) overlying a large oval Dacron mesh-reinforced back patch (c). Tissue (d) was meant to grow through the holes into the fixation patches, thereby affixing the implant to the surrounding tissues. Also shown is a Dacron mesh full-loop suture tag inferiorly (e) (see Fig 38).

View larger version (111K): [in a new window]   Figure 36. Fenestration-style fixation patch. Heyer-Schulte single-lumen silicone gel-filled implant (placed 1984) with a "butterfly"-shaped fenestration-style fixation patch (a) overlying a "spiral" (multiple concentric circles) back patch (b) on which is marked "200" (c, the implant size in cubic centimeters). Tissue was meant to grow through the holes in the fixation patch, thereby affixing the implant to the surrounding tissues. This style of fenestration patch will rarely if ever be discernible on MR images.

View larger version (120K): [in a new window]   Figure 37. Fenestration-style fixation patch. Cox-Uphoff International (CUI) single-lumen silicone gel-filled implant with a round fenestration-style fixation patch (a) overlying the superior portion of the posterior shell. Tissue was meant to grow through the holes in the fixation patch, thereby affixing the implant to the surrounding tissues. Also present is a back patch outside the implant shell (b) with a central gel fill point (c), and a small elastomer disk (d) holding a Dacron mesh suture tag (e) on the inferior implant shell.

View larger version (95K): [in a new window]   Figure 38. Full-loop suture tag. Full-loop Dacron fine-mesh suture tag (a) on a Heyer-Schulte implant placed in 1975, bonded to the underlying spiral patch (b) with a small overlying round elastomer disk (c). This style of suture tag was used by Heyer-Schulte until about 1978. Note the indentation into the shell by the suture tag (d). Such indentations may potentially be sites of shell failure (ie, rupture). Although suture tags such as these may rarely be visualized on MR images, their MR imaging appearance is neither manufacturer nor style specific.

View larger version (80K): [in a new window]   Figure 39. Partial-loop suture tag. Side view of a ruptured Surgitek (MEC) 10140 single-lumen teardrop-shaped silicone gel-filled implant with an attached 4-mm-wide Dacron coarse-mesh partial-loop suture tag (a) inserted between the implant back patch and the shell (placed 1976). This type of suture tag formed a partial loop, as shown here, and could be sewn to surrounding tissue, providing a degree of fixation to surrounding tissue. Free silicone gel is seen on the implant surface extending to the suture tag (b). A top view of this same suture tag is shown in Figure 40. Although suture tags such as these may rarely be visualized on MR images, their MR imaging appearance is neither manufacturer nor style specific.

View larger version (110K): [in a new window]   Figure 40. Partial-loop suture tag. Top view of the same suture tag (a) shown in Figure 39, showing edge of overlying back patch (b).

View larger version (127K): [in a new window]   Figure 41. Dacron mesh-reinforced round-tip elastomer suture tag. Dacron mesh-reinforced round-tip elastomer suture tag (a) on a Style 6000 Heyer-Schulte single-lumen silicone gel-filled implant (placed 1982). Just the edge of the "spiral" (multiple concentric circles) back patch is seen here (b). This style of suture tag was used by Heyer-Schulte from about 1978 to 1984 and by Mentor after that. Although suture tags such as these may rarely be visualized on MR images, their MR imaging appearance is neither manufacturer nor style specific.

View larger version (88K): [in a new window]   Figure 42. Keyhole-shaped Dacron mesh-reinforced suture tag. Dacron mesh-reinforced keyhole- (or paddle-) shaped elastomer suture tag (a) on a Style 82 McGhan single-lumen silicone gel-filled implant (placed 1977). This style of suture tag was used by McGhan and McGhan/3M on some of their nonround implants. The suture tag is bonded just outside the implant shell patch (b), under a small elastomer disk (c), with the gel-fill point just on top of that (d). Note the tendency of the distal part of the tag to assume a curved shape, which may have contributed to the indentation in the implant shell under the tag (not shown here). Although suture tags such as these may rarely be visualized on MR images, their MR imaging appearance is neither manufacturer nor style specific.

View larger version (143K): [in a new window]   Figure 43. Elastomer orientation bar and disk. An inferior horizontal orientation bar (a) and superior round disk (b) are placed directly external to the back patch (c) and shell of this specially ordered variation of a McGhan/3M Style 81 implant (1981, Tampa, Fla). The implant patch is set inside the shell and has a "hammertone" appearance (ie, an irregular fine-scale roughening). A small raised gel fill point is seen inferior to the bar on the inferior edge of the patch (d). The shell was marked "265" in a "filled" numeral typeface inferior to the back patch and facing away from the patch (not shown here), in a configuration sometimes used by this manufacturer. A horizontal bar and external disk also were used on some specially ordered Heyer-Schulte (1975-76) and Surgitek (1984-86) implants from Tampa, Florida. These orientation features will rarely if ever be discernible on MR images.

View larger version (131K): [in a new window]   Figure 44. Orientation bar on implant shell. Dow Corning 930 series implant (placed about 1979) with a vertical 40-mm bar (unlabeled arrows) on the posterior inferior implant shell next to the back patch, meant to assist the surgeon in aligning the implant properly at time of placement. Note also the Dacron mesh-reinforced elastomer reinforcement disk (a) seen here internal to the Dacron mesh-reinforced elastomer back patch (b) (see Figs 48 and 49). The orientation bar will rarely if ever be discernible on MR images; however, with adequate resolution and experience, the MR imaging appearance of the internal Dacron mesh-reinforced elastomer disk can be specific for some Dow Corning implants from this period.

View larger version (99K): [in a new window]   Figure 45. Orientation dot on implant shell. A white orientation dot (a) is seen here attached directly to the implant shell of this Cox-Uphoff International (CUI) implant (placed 1977), adjacent to its back patch (b). The inner projection of the white dot is disklike with squared edges, about 8-9 mm in diameter, and its projection outside the implant shell is domelike. The raised gel-fill point (c) is seen centrally on the back patch. These dome-shaped white orientation dots were sometimes placed centrally on the back patch. They may sometimes be seen on MR images and, given adequate resolution and experience, may be distinguishable from the internal reinforcement disks used on Dow Corning implants from about the same period or earlier.

View larger version (95K): [in a new window]   Figure 46. Textured implant surface. Sagittal T2-weighted fast spin-echo water-suppressed MR image of an intact Dow Corning SILASTIC MSI single-lumen silicone gel-filled breast implant (placed 1991). Note that the intracapsular waterlike fluid surrounding this implant, and within the implant folds, is dark (arrows). Silicone gel within the implant is bright (a). The large fold extending all the way across the implant is a normal appearance of some implants.

View larger version (105K): [in a new window]   Figure 47. Textured implant surface. Silicone-suppressed T2-weighted MR image of the same Dow Corning SILASTIC MSI single-lumen silicone gel-filled breast implant shown in Figure 46. A layer of intracapsular waterlike fluid (high signal intensity) is often present around textured implants, such as is seen here, with what has been called a "picture frame" appearance (3). The silicone gel (a) in this implant has low signal intensity on this type of image.

View larger version (89K): [in a new window]   Figure 48. Internal reinforcement disk. From about 1971 to 1977, Dow Corning placed a small elastomer disk (a) centrally along the internal surface of the back patch (b) of many of their implants. These disks were about 12 mm in diameter, mostly Dacron mesh-reinforced like the one shown here. Their purpose was to help seal the hole through which silicone gel was originally placed into the implant. This patch and disk are from a Dow Corning no. 956 implant placed in 1977, and both are Dacron mesh reinforced, viewed here showing their inner surface. With adequate resolution and experience, most of these disks can be seen on MR images, as shown in Figure 49, and their appearance on MR images may be specific for some Dow Corning implants.

View larger version (86K): [in a new window]   Figure 49. Internal reinforcement disk. Axial T2-weighted fast spin-echo water-suppressed MR image of the type of Dow Corning implant with an internal reinforcement disk (placed 1977) shown in Figure 48. The ends of the back patch are indicated with thin arrows, and the internal reinforcement disk with a thick arrow. This MR image shows a "pull-away" sign (3), indicating that this implant is in a state of uncollapsed rupture (a), confirmed at surgery.

View larger version (127K): [in a new window]   Figure 50. Smooth implant shell. Sagittal fast spin-echo T2-weighted water-suppressed MR image of an intact Cox-Uphoff International (CUI) single-lumen silicone gel-filled smooth shell implant (placed 1987). A normal fold of the implant shell, seen here as a dark thin line "within" the gel, can be seen extending all the way across the implant.

View larger version (142K): [in a new window]   Figure 51. Polyurethane-coated implants. Posterior surface of an early Natural-Y polyurethane-coated implant (placed 1979) after removal, showing the polyurethane remaining in the adhesive coat, partially denuded in places. The back patch (arrow) is not easily visible because of the layer of adhesive and polyurethane. The internal Y-shaped baffle is not discernible on this photograph. The internal baffle in this type of implant is usually evident on MR images, as shown in Figure 52.

View larger version (90K): [in a new window]   Figure 52. Polyurethane-coated implants. Sagittal T2-weighted fast spin-echo water-suppressed MR image of a much earlier version (placed 1970) of the same type of implant (Natural-Y) shown in Figure 51, with a portion of the internal baffle (arrow) well visualized. Note the unusually thick implant shell and the rather abrupt angles at the edges of the base of the implant, where the posterior flat shell piece is "seamed" to the anterior contoured shell piece, typical of the earlier polyurethane-coated implants. In our experience, this type of polyurethane-coated implant has the specific appearance of the Y-shaped internal baffle seen here5 .

View larger version (95K): [in a new window]   Figure 53. Polyurethane-coated implants. The surface of this Optimam implant (placed 1984) is mostly denuded of polyurethane. Note the cream-colored shell, rather than the usual clear shell, and the cream-colored back patch (arrow) placed outside the shell that is smaller than the patch used on some of the earlier Natural-Y implants. This kind of patch was also used in the Vogue implants and some Natural-Y infraclavicular implants. The Optimam and Vogue implants commonly had an internal Y-shaped baffle, recognizable on MR images.

View larger version (123K): [in a new window]   Figure 54. Polyurethane-coated implants. Aesthetech Même ME single-lumen silicone gel-filled implant (placed 1984), intact, with a layer of surface adhesive still present. Most of the polyurethane layer is no longer present, a common finding in explanted implants of this style. The shells of these implants were sometimes extremely thin, making their detection after rupture difficult. The gel often has some degree of "memory", and so it is common that the implant will show deep persistent folds and involutions in its shape, even when explanted and only under the influence of gravity and not subjected to compression. Most of these were created by forming silicone gel into the desired shape and then dipping into more silicone and "curing" to form the shell. The MR imaging appearance of this kind of implant is shown in Figure 55.

View larger version (106K): [in a new window]   Figure 55. Polyurethane-coated implants. Sagittal T2-weighted fast spin-echo water-suppressed MR image of a ruptured Aesthetech Même ME implant (placed 1984), similar to the one shown in Figure 54. Note the very thin implant shell, which has a crinkled appearance that we have seen associated with only this style of implant, consistent with the persistent folds and "gel with a memory" that are commonly found in these implants. Internal gas bubbles, which are common in polyurethane-coated implants, are also seen.

View larger version (86K): [in a new window]   Figure 56. Polyurethane-coated implants. Posterior surface of an Aesthetech Replicon implant (placed 1988) shows the characteristic "ring" appearance (arrow) of the back patch, seen in no other implant of which we are aware. The ring appearance is usually caused by the overlap of the implant shell itself, a larger patch inside the implant shell and a smaller patch outside the shell.

View larger version (111K): [in a new window]   Figure 57. McGhan/3M Style 80 back patch. Back patch of intact McGhan/3M Style 80 smooth-shell single-lumen silicone gel-filled implant (placed 1979). This implant is identifiable because of the presence of a "hammertone" (textured-looking) back patch set just inside the implant shell hole (a), a peripheral gel fill point (b), where the back patch overlaps the implant shell, and a flat approximately 7.5-mm white dot (c) centrally placed outside the back patch. Not shown are shell markings "240" just inferior to and facing away from the back patch in a typeface characteristic for this manufacturer. This style of back patch from this manufacturer generally is not identifiable as such on MR images.

View larger version (84K): [in a new window]   Figure 58. Reverse double-lumen adjustable implant. Axial T2-weighted fast spin-echo water-suppressed MR image of the Surgitek reverse-adjustable double-lumen implant (placed 1985) shown in Figure 15. This image shows the normal water-suppressed appearance of mixed saline (a, dark) and silicone gel (b, bright), both in the inner lumen, and silicone gel in the outer lumen (c). In this case, the inner lumen is not fully "inflated" and so has the characteristic "plateau next to a peak" appearance. The silicone-suppressed appearance of this implant is shown in Figure 59, and the xeromammographic appearance is shown in Figure 60. In our experience, this type of implant from this manufacturer is identifiable on MR images.

View larger version (69K): [in a new window]   Figure 59. Reverse double-lumen adjustable implant. Axial T2-weighted fast spin-echo silicone-suppressed MR image of the Surgitek reverse-adjustable double-lumen implant (placed 1985) shown in Figure 15. This image shows the normal silicone-suppressed appearance of mixed saline (a, bright) and silicone gel (b, dark), both in the inner lumen, and silicone gel in the outer lumen (c). The water-suppressed appearance of this implant is shown in Figure 58, and the xeromammographic appearance is shown in Figure 60.

View larger version (91K): [in a new window]   Figure 60. Reverse double-lumen adjustable implant. Xeromammogram of the Surgitek reverse-adjustable double-lumen implant (placed 1985) shown in Figures 15, 58, and 59, showing the same internal structure seen in more detail on the MR images.

View larger version (79K): [in a new window]   Figure 61. Single-lumen gel-saline implant. Axial T2-weighted fast spin-echo water-suppressed MR image of an intact Surgitek gel-saline single-lumen implant (placed 1986) with a leaflet valve, showing the normal appearance of numerous waterlike bubbles (a, dark) mixed with silicone gel (b, bright). A cross section through the distal flat part of the leaflet valve is shown (arrow). The presence of numerous waterlike bubbles within what appears to be a single-lumen silicone gel-filled implant should, especially when a leaflet valve is visualized, indicate that one is probably dealing with a single-lumen adjustable implant. The same appearance can be seen in cases in which the surgeon injects large amounts of saline directly into the implant with a small-gauge needle at the time of placement.

View larger version (75K): [in a new window]   Figure 62. Single-lumen gel-saline implant. Fast multiplanar inversion-recovery fat-nulled T2-weighted water-suppressed MR image of a gel-saline Surgitek implant (placed 1981) with an SSI valve (a). Note that the valve contents do partially suppress on this water-suppressed image because of the saline that remains from time of placement or from waterlike fluid that has leaked into it from outside the implant. The contents of the valve also usually do not entirely suppress on silicone-suppressed images (not shown here). The presence of silicone gel outside the SSI valve indicates that this implant is ruptured (arrow). The MR appearance of the SSI valve shown here (a) is specific for this implant.

View larger version (20K): [in a new window]   Figure 63. Birnbaum custom gel-gel double-lumen implant. Schematic of the McGhan and McGhan/3M Birnbaum-style custom gel-gel double-lumen implant. Illustrated here are three "keyhole"- (or "paddle"-) shaped Dacron mesh-reinforced suture tags (see Fig 42), a hemispheric inner flat gel-filled lumen (dotted line) with its shared back patch (a), and the outer silicone gel-filled lumen with its separate back patch (b). The actual appearance of an implant of this type is shown in Figure 64, and the MR imaging appearance is shown in Figure 65.

View larger version (98K): [in a new window]   Figure 64. Birnbaum custom gel-gel double-lumen implant. View of the posterior surface of a McGhan/3M implant (placed 1978) of the type shown in Figure 63. The patches are darkened compared with the color usually seen. One possible explanation is that this represents an extreme case of the yellowing with age that has been reported to be likely due to the formation of colloid platinum with crystallites larger than 2.2 nm, where the platinum serves as a catalyst for hydrosilylation reactions that form the gel and shell (147). This darkening, sometimes more marked than seen here, is not uncommonly seen in some McGhan/3M and Heyer-Schulte implants from the late 1970s and early 1980s. The inner upper lumen is shaped like a folded-over pita bread (delineated by arrows). The implant is photographed here from the side.

View larger version (115K): [in a new window]   Figure 65. Birnbaum custom gel-gel double-lumen implant. Sagittal T2-weighted fast spin-echo water-suppressed MR image of the type of implant (McGhan, placed 1987) shown in Figures 63 and 64. Shown here is the decreased T2 signal from the more highly crosslinked inner-lumen gel (a) and the brighter gel from the (ruptured) outer lumen (b). The smaller (shared) upper back patch for the inner lumen is seen here as a darker, thicker line adjacent to the thicker gel layer of the inner lumen (arrow). Although the appearance of this kind of implant can be complicated, together with the patient history, this type of implant should be identifiable on MR images.

View larger version (100K): [in a new window]   Figure 66. Triple-lumen implant. Axial T2-weighted fast spin-echo water-suppressed MR image showing silicone gel in the inner (a) and middle (b) lumens of this triple-lumen McGhan implant placed in 1988. The saline is gone from the outer lumen of this implant. Note the usual buckled appearance (arrow) of the fold in the inner lumen shell anteriorly, adjacent to the middle lumen, a nearly constant feature for the McGhan and McGhan/3M triple-lumen implants (3). This is not a sign of rupture.

View larger version (98K): [in a new window]   Figure 67. Cavon implant. The surface of this Cavon "cast gel" implant (placed 1985), shown here just as it was being removed from the fibrous capsule at surgery, has the distinctive "elephant skin" appearance we have seen only for this kind of implant. No discernible shell or back patch is present. The MR imaging appearance of this implant is shown in Figure 68.

View larger version (89K): [in a new window]   Figure 68. Cavon implant. Sagittal T2-weighted fast spin-echo water-suppressed MR image of the Cavon implant (placed 1985) shown in Figure 67. Some ill-defined internal lines are seen that do not have the appearance of implant shell. At surgery, the implant was found to have an appearance suggesting that it had been injected with some substance, probably steroid and/or antibiotic, possibly accounting for the irregular internal lines. Incidentally noted is some (bright) silicone fluid in the soft tissues surrounding this implant due to previous silicone fluid injections.

View larger version (129K): [in a new window]   Figure 69. Custom implant. Ruptured custom infraclavicular Natural-Y polyurethane-coated breast implant (placed 1979), posterior surface. The characteristic type of external shell patch for this type of implant is seen in the upper left part of this photograph of the implant (arrow).

View larger version (110K): [in a new window]   Figure 70. Custom implant. Custom Heyer-Schulte implant specially designed for patient with Poland syndrome (placed 1973). Two Dacron mesh-reinforced elastomer back patches are seen on the posterior surface of the implant (a), along with three (of the original four) Dacron felt strips (b). Also seen within the implant is a polyurethane sponge (c), to which is sewn a layer of loose Dacron mesh (d). This type of implant should have a distinctive appearance on MR images, although we have never imaged one.

View larger version (98K): [in a new window]   Figure 71. Custom implant. Custom "piggyback" Custom "piggyback" Georgiade Surgitek implant (placed 1978), consisting of a smaller (100 mL) anterior contoured single-lumen silicone gel-filled implant (in a state of uncollapsed rupture) (thick arrow), shown here maintaining its original contoured shape, attached directly to a larger (185 mL) posterior single-lumen silicone gel-filled implant, shown here ruptured with the attached fragments of its shell laid out symmetrically (thin arrows) (148).

View larger version (88K): [in a new window]   Figure 72. Soft pectus implant. This McGhan/3M soft pectus implant placed in 1984 uses fenestration-style fixation (small holes around the edge of the implant and in the right lower part of the implant on this photograph), three keyhole-shaped Dacron mesh-reinforced elastomer suture tags (a), one partially torn off the implant (see Fig 42), and three Dacron felt fixation disks (b, with some tissue still attached). Tissue has grown into the holes in the fenestration part of the implant and into the Dacron felt fixation disks. The MR imaging appearance of this implant is shown in Figure 73.

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