DOI:10.2214/AJR.05.2237
AJR 2006; 187:W436-W437
© American Roentgen Ray Society
Gel-Gel Double-Lumen Silicone Breast Implant: Mimic of Intracapsular Implant Rupture
Jin-Wei Kwek,
Haesun Choi,
Jingfei Ma and
Michael J. Miller
Tan Tock Seng Hospital Singapore 308433
The University of Texas M. D. Anderson Cancer Center Houston, TX
77030
WEB—This is a Web exclusive article.
A 38-year-old woman presented with a decrease in breast implant volume. She
had a strong family history of breast cancer and underwent bilateral
prophylactic mastectomies and bilateral mammoplasties 7 months before
presentation. Physical examination revealed a good cosmetic outcome with no
contour abnormality or definite evidence of leakage. Nonetheless, MRI of the
breast was ordered because of the patient's concern of implant rupture.
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Fig. 1A —38-year-old woman with decrease in breast implant volume 7
months after bilateral prophylactic mastectomies and mammoplasties. Sagittal
(A) and axial (B) silicone-specific inversion-recovery-prepared
fast two-point Dixon images, obtained with TR/TE, 5,400/68 and inversion time,
140 msec, show presence of silicone in both lumens. Shell of inner lumen
(black arrows) mimics appearance of "lumen within a
lumen." Note presence of thick, hypointense line of shell patch located
posteriorly (white arrows).
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Fig. 1B —38-year-old woman with decrease in breast implant volume 7
months after bilateral prophylactic mastectomies and mammoplasties. Sagittal
(A) and axial (B) silicone-specific inversion-recovery-prepared
fast two-point Dixon images, obtained with TR/TE, 5,400/68 and inversion time,
140 msec, show presence of silicone in both lumens. Shell of inner lumen
(black arrows) mimics appearance of "lumen within a
lumen." Note presence of thick, hypointense line of shell patch located
posteriorly (white arrows).
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Fig. 1C —38-year-old woman with decrease in breast implant volume 7
months after bilateral prophylactic mastectomies and mammoplasties. Sagittal
(C) and axial (D) silicone-suppressed
inversion-recovery-prepared fast two-point Dixon images, obtained with
5,617/63 and inversion time, 450 msec, confirmed presence of silicone in both
lumens. Rippling of outer lumen is noted with chemical shift artifacts
(arrows, C).
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Fig. 1D —38-year-old woman with decrease in breast implant volume 7
months after bilateral prophylactic mastectomies and mammoplasties. Sagittal
(C) and axial (D) silicone-suppressed
inversion-recovery-prepared fast two-point Dixon images, obtained with
5,617/63 and inversion time, 450 msec, confirmed presence of silicone in both
lumens. Rippling of outer lumen is noted with chemical shift artifacts
(arrows, C).
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Silicone-specific and silicone-suppressed T2-weighted images (Figs.
1A,
1B,
1C, and
1D) of the right breast
acquired using an inversion-recovery-prepared fast two-point Dixon technique
showed an implant with two lumens, both of which were filled with silicone.
The inner wall of the implant appeared collapsed, suggesting an intracapsular
rupture of a single-lumen silicone gel breast implant in a "lumen within
a lumen" appearance. However, further evaluation of the
silicone-specific T2-weighted sagittal images indicated that the inner wall of
the implant merged into the low-signal back patch (Figs.
1A,
1B,
1C, and
1D), consistent with an intact
double-lumen silicone gel implant. A review of the patient's surgical history
confirmed that the implant was a double-lumen silicone gel implant (Inamed,
style 153; McGhan).
Although the clinical management of asymptomatic ruptured breast implants
has been debated, the importance of detecting implant ruptures is relevant,
especially with the continual increase in mammoplasty procedures and the
significantly higher incidence of implant rupture than has been previously
suspected [1]. An implant
rupture can be either intracapsular or extracapsular. The MRI findings of
ruptured single-lumen breast implants have been well described
[2].
Detection of an extracapsular rupture or silicone leakage outside of the
implant is relatively easy on silicone-specific MR images favorably acquired
with the inversion-recovery-prepared two-point Dixon technique
[3]. Detection of an
intracapsular rupture, however, can be challenging. An intracapsular rupture
can be a total collapse of the inner capsule, creating a "lumen within a
lumen" appearance on the MR image, or it can be a focal collapse with
multiple intraluminal linear hypointense structures within the silicone-filled
lumen ("linguine" sign or "subcapsular line") or a
focal silicone collection in radial folds ("noose" or "
keyhole" sign) [2]. The
MRI findings of a double-lumen breast implant, however, have not been fully
described, primarily because double-lumen implants are used in less than 1% of
implant procedures [2].
The inner lumen of the Inamed style 153 implant is relatively overfilled
with silicone gel, retains a nearly spherical shape, and is located in the
lower half of the implant to provide a natural shape. The outer lumen is
filled only partially with silicone gel and may show rippling on an MR image
(Figs. 1A,
1B,
1C, and
1D). The implant has two
gel-filled points merged to the back patch, as seen in our case, and has a
textured surface to reduce the incidence of capsular contracture. Therefore,
confirmation of a linear low-signal patch using both axial and sagittal images
(Figs. 1A,
1B,
1C, and
1D) can help to correctly
identify the type and integrity of the implant. Although the appearance of a
ruptured gel-gel double-lumen implant on MR images can be complicated, the
back patch of the inner lumen may be seen along the collapsed inner wall
separated from the outer wall
[4]. Knowledge of the normal
appearance of different types of implants is particularly important when no
clinical information is available. Otherwise, the MRI appearance of the intact
inner lumen of a gel-gel double-lumen implant can be mistaken for a total
collapse of a single-lumen implant.
References
- Brown SL, Middleton MS, Berg WA, Soo MS, Pennello G. Prevalence of
rupture of silicone gel breast implants revealed on MR imaging in a population
of women in Birmingham, Alabama. AJR2000; 175:1057
-1064[Abstract/Free Full Text]
- Beekman WH, van Straalen WR, Hage JJ, Taets van Amerongen AH,
Mulder JW. Imaging signs and radiologists' jargon of ruptured breast implants.
Plast Reconstr Surg 1998;102
: 1281-1289[Medline]
- Ma J, Choi H, Stafford RJ, Miller M. Silicone-specific imaging
using an inversion recovery-prepared fast three-point Dixon technique.
J Magn Reson Imaging 2004;19
: 298-302[CrossRef][Medline]
- Middleton MS, McNamara MP Jr. Breast implant classification with MR
imaging correlation. Radio-Graphics 2000;20
: E1. Available online only
at:
http://radiographics.rsnajnls.org/cgi/content/full/20/3/e1.
Accessed July 3, 2006[Medline]
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