M R imaging is more accurate than mammography or sonography for detecting implant rupture F 1-4].

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1 Pictorial MR Imaging of Breast Implants andtheir Complications Desiree E. Morgan1, Philip J. Kenney1, Marilyn C. Meeks2, Nancy S. Pile1 M R imaging is more accurate than mammography or sonography for detecting implant rupture F 1-4]. MR imaging is also useful for evaluating capsular contracture and herniation of the implant through the fibrous capsule and for detecting silicone within lymph nodes and breast tissue. This essay shows the wide variation of MR imaging findings in normal and complicated implants in a large series imaged with a consistent technique. We examined with MR imaging 185 women with 345 breast implants (226 silicone. 52 double-lumen. and 67 saline). One hundred sixty-one patients had bilateral implants, nine patients had unilateral implants. and three patients had more than two implants. Twelve patients had fl() implants at the time of our study. but had had silicone implants in the past. The number of patients reporting local symptoms including breast pain and burning or altered breast size or shape was I 26. Nineteen patients also reported systemic symptoms including arthralgia. paresthesia. or fatigue. Eight patients either had rheumatologic symptoms or carried rheumatologic diagnoses. Forty of the patients were asymptomatic. Seventythree implants were removed from 36 patients in the surgical subpopulation of this series. Received January 4, 1996;accepted after revision May 14, All scans were obtained on a I.5-T scanner (Siemens Medical Systems. Iselin. NJ) using a dedicated dual-breast surface coil and commercially available imaging sequences including fat-suppressed fast inversion recovery dual-echo sequences (turbo short inversion time inversion recovery IturboSTIRl) in the axial. coronal. and sagittal planes with these parameters: TR range/first-echo TE and seeond-echo TE. 4()OO-5000/19 and 93: inversion time. 1(X) msec: thickness. 5 mm: excitations. one: matrix size, 192 x 256. A T2-weighted gradient-echo sequence (threedimensional precession steady-state imaging fast sequence) was filmed in the coronal plane with these parameters: 17/7: flip angle. 70#{176}: slab. I 30 mm: excitations. one: matrix size. 128 x 256. Silicone-suppressed turhostir sequences were obtained in the coronal and axial planes with these parameters: 4(X)0-500()/l9: inversion time. 400 msec: thickness. 7 mm: excitations, one: matrix size. 192 x 256. Total imaging time was approximately 45 mm. Patients were scanned in the prone position. All patients with MR imaging evidence of rupture were referred for explantation. Correlation was made with surgical findings and pathologic evaluation of the implants. Normal Implant Appearances Silicone Essay Most implants are single-lumen silicone prostheses. which contain an outer elastomer silicone shell (or envelope) surrounding silicone gel (Fig. I ). The surfttce of the implant may be smooth or textured, the latter thought to decrease formation of capsular contractures. With the textured implants. small amounts of reactive fluid with the signal characteristics of serum are often seen surrounding the elastomer shell and do not mdicate abnormality I I I. Likewise. a few isolated water signal intensities within the silicone gel are sometinles seen in normal. intact implants and are not a reliable sign of rupture (I. 4]. Folding or inward invagination of the implant shell is common and sometinles complex. The low-signal-intensity radial folds of the shell always abut the periphery and span the substance of the gel only at the periphery. They thus can be differentiated from a ruptured implant. in which the partially collapsed shell need not approach the edge of the implant and may cross the gel in any configuration. Using three orthogonal imaging planes. f-lds can be followed on sequential images and differ- Presented at the annual meeting of the American Roentgen Ray Society, Washington, DC, April-May tdepartment of Radiology, University of Alabama, 619 S. 19th St., Birmingham, AL Address correspondence to 0. E. Morgan. 2Oepartment of Internal Medicine, University of Alabama, Birmingham, AL AJR 1996;167: X/96/ American Roentgen Ray Society AJR:167, November

2 Morgan et al. entiated froni a collapsed. ruptured envelope. sional precession steady-state imaging fast which is often discontinuous on sequential images. In general. silicone has a high signal images 12]. In most patients. a f ibrous cap- intensity on fat-saturated turhostlr images. sule (representing a normal foreign body an intermediate signal intensity on precesresponse) forms around the implant and is sion steady-state imaging fast images. and a represented on MR imaging by a dark. ringlike very low signal intensity on silicone-sup- structure 121. A low-signal-intensity cap- pressed sequences. sule of reactive fibrous tissue of varying thickness may be seen surrounding the Saline implant and is best seen on the three-dimen- Single-lumen saline iniplants contain a Fig. 1.-Normal single-lumen silicone implants. A, Scout Ti-weighted MR image shows similarity in signal intensities of silicone implants and fat Unilateral sagittal imaging allows placement of saturation band over heart (not possible with bilateral imaging). B, Axial fat-suppressed turbo short inversion time inversion recovery (turbostlr) image shows smooth, ovoid subglandular implants with high signal intensity. Several normal, low-signal-intensity folds (arrows) are seen originating at periphery of implants. C. Axial silicone-suppressed turbosllr image shows drop in signal intensity of implants, whereas fat signal intensity remains high. D, Coronal precession steady-state imaging fast image shows signal intensity of silicone implant to be similar to that of surrounding fat. Note better display of fibrous capsule (arrows). variable amount of saline within an elastomer silicone shell. Often, valves used to adjust the volume within the implant are visible (Fig. 2). Saline implants are expected to deflate 1-5% over the first 2 years. a phenomenon that increases temporally. As the implant collapses. complex infolding patterns may be noted. The presence of fluid outside the shell is not specific for rupture in these patients but may be due to normal migration of saline Fig. 2.-Normal single-lumen saline implants. A, Axial fat-suppressed turbo short inversion time inversion recovery image shows smooth ovoid contour of implants with valves (solid arrows); note small amount of fluid along medial aspect of both implants (open arrows). B, Coronal precession steady-state imaging fast image shows high signal intensity of implants; adjacent reactive fluid (arrows) is slightly lower in intensity. Lower signal of reactive fluid may be due to proteins and other serous substances reducing 12 relaxation. Such reactive fluid is not reliable sign of rupture [ii. Fig. 3.-Normal double-lumen implants. A, Coronalfat-suppressed turbo short inversion time inversion recovery image shows central silicone component with higher-signal-intensity saline in outer lumen. B, Coronal silicone-suppressed turbo short inversion time inversion recovery image shows higher signal intensity of saline component compared with inner silicone component Note extensive interdigitation, with invagination of inner elastomer shell due to loss of volume of saline component Fig. 4.-Normal reversed double-lumen implants. A, Coronal fat-suppressed turbo short inversion time inversion recovery (turbostlr) image reveals high signal intensity centrally, with intermediate signal intensityfrom outer lumen. B, Coronal silicone-suppressed turbosllr image shows drop in signal intensity of silicone in outer lumen. This type of implant may be used in reconstruction because of variable filling potential of saline component; outer silicone component gives more natural consistency to breast 1272 AJR:167, November 1996

3 MR Imaging of Breast Implants across the capsule, reactive serous fluid, or leakage. Saline implants have a higher signal intensity than silicone implants on fat-suppressed turbostlr and precession steadystate imaging fast sequences and do not lose signal intensity on silicone suppression sequences. Double Lumen Most double-lumen implants contain two elastomer shells with silicone gel in the inner shell and saline in the outer shell (Fig. 3). The outer saline component was added to reduce silicone gel bleeding (the microscopic migration of silicone gel through the elastomer shell) and associated capsular contracture ] I I. The reverse double-lumen implant. often used in reconstruction, has two elastomer shells with a variable volume of saline in the inner shell and silicone in the outer shell (Fig. 4). As in singlelumen saline implants. the saline component of a double-lumen implant deflates over time, giving rise to complex infolding patterns and occasionally nonspecific fluid surrounding the outer capsule of the implant. The term stacked implants refers to the presence of more than one implant per breast, a technique used in breast reconstruction (Fig. 5). Abnormal Implant Appearances Rupture The frequency of rupture in asymptomatic women is reported to be from 0.2% to 6.0% [5]. Implants found to be ruptured at surgery are on average older than those found to be intact I 1]. Gorcyzca et al. [3] reported that the rate of rupture was similar for subglandular and subpectoral implants. MR imaging has a 76_95c/c sensitivity and 93-97% specificity [2-4] for the detection of rupture, which has been categorized as either intracapsular or extracapsular. Intracapsular rupture (Figs. 6 and 7) is much more common and occurs when the elastomer shell breaks down and silicone is confined by the fibrous capsule. When the elastomer shell ruptures, it may assume differing degrees of collapse. If completely collapsed and folded within the silicone gel, the low-signal-intensity elastomer shell has the appearance of linguine 161. The linguine sign. first coined by Gorcyzca et al., is the most reliable MR imaging sign of intracapsular rupture 121. Extensive gel bleeding (microscopic silicone gel leakage through A Fig. 5.-Complicated stacked implant. A, Sagittal fat-suppressed turbo short inversion time inversion recovery image of right breast shows saline implant inferiorly and silcone component superiorly. Note several high-signal-intensity droplets within silicone. B, Coronal precession steady-state imaging fast image shows stacked implants on right and normal silicone implant on left. Several small foci with signal intensity similar to that of saline are seen in silicone; this phenomenon can be seen in rupture but, in absence of other findings, is not reliable sign of rupture [11. Fig. 6.-Intracapsular rupture. A, Sagittal fat-suppressed turbo short inversion time inversion recovery image shows single-lumen silicone implant in subpectoral location. Note long curvilinear low-signal-intensity band within silicone, representing collapsed elastomer envelope (linguine sign) Silicone remains confined by fibrous capsule. B, Coronal precession steady-state imaging fast image shows completely collapsed left shell and partially collapsed right shell (short arrows). Note fluid droplets in silicone (long arrows). Although nonspecific alone, combination of fluid droplets and linguine sign is evidence of rupture 111.Bilateral intracapsular rupture was surgically confirmed. an intact shell) may be difficult to ditthrentiate froiii early intracapsular rupture and may be identified by the presence of silicone within the leaves of an invaginated radial fld 141- Extracapsular rupture (Figs. 8 and 9 is breakdown of the shell with macroscopic extrusion of silicone gel beyond the fibrous Fig. 7.-Intracapsular rupture. A, Axial fat-suppressed turbo short inversion time inversion recovery image reveals bilateral subpectoral single-lumen implants with complex curvilinear lowsignal-intensity structure within left implant. B, Coronal precession steady-state imaging fast image better shows collapsed elastomer envelope on left, because of higher spatial resolution of three-dimensional volume acquisition (1.5-mm slices). At surgery, implant was completely ruptured, with shredded fragments of shell within gel. Note mild bulge of lateral aspect of right implant (arrows), which was intact at surgery. B AJR:167, November

4 Morgan et al. Fig. 8.-Extracapsular rupture. A, Coronal fat-suppressed turbo short inversion time inversion recovery (turbostlr) image reveals bilateral subglandular silicone implants with well-defined fibrous capsule on right. On left, note silicone extending through capsule into adjacent breast tissue (short arrows). One-centimeter ovoid high-signal-intensity structure at medial left chest wall is consistent with silicone in lymph node (long arrow). B, Axial fat-suppressed turbostlr image shows high signal intensity external to fibrous capsule (arrows). C, Silicone-suppressed turbostlr image at same level shows drop in signal intensity of both implants and extruded silicone. Fig. 10.-Capsular contracture. Coronal fat-suppressed turbo short inversion time inversion recovery image shows bilateral subglandular silicone implants. Focal serrated appearance of left implant is typical of capsular contracture. Note also bulge at medial aspect of right implant. Fig. 11.-False-positive MR imaging. Axial fat-suppressed turbo short inversion time inversion recovery image shows apparent medial extension of silicone (arrow), thought to represent extracapsular rupture in this patientwith bilateral silicone implants. No other findings of rupture were present Atsurgery, implantwas intact Findingswere due to fibrous contracture and herniation. Fig. 9.-Extracapsular rupture. A, Sagittal fat-suppressed turbo short inversion time inversion recovery (turbosllr) image of right breast shows linguine sign (thick arrows). Note also ovoid structures in anterior breast parenchyma; more supenor lesion (thin arrows) has signal intensity similar to that of silicone, whereas inferior lesion (open arrow) is cyst B, Sagittal fat-suppressed turbostlr image slightly more lateral than in A shows 1.2-cm silicone deposit (arrows) inferior to implant. capsule. With MR imaging, silicone can be seen beyond the low-signal-intensity fibrous capsule within adjacent breast parenchyma. I I 1. This may be manifested by saline droplets floating within the silicone gel on MR imaging and is a form of intracapsular rupture. Ag. 12.-False-negadve MR imaging. Sagittal fat-suppectoral niuscle. or lymph nodes 171- pressed turbo short inversion time inversion recovery im- Because of the unique hicompartmental Capsular Controcture age shows slight irregularity (arrows) posteriorto silicone implant, thoughtto be due to identification disk or possibly nature of double-lumen iiiiplants. failure of the Capsular contracture is the most conimon gel bleed. At surgery, in-acapsuiar rupture was present, inner shell has been termed internal rupture long-term complication of breast implanta- with only small film of extruded gel in this locadon AJR:167, November 1996

5 MR Imaging of Breast Implants tion and is seen in 10-25% of patients with smooth-walled silicone prostheses. Asymmetric, serrated, focal folding of the fibrous capsule causing an alteration of the normal ovoid appearance of the breast implant is characteristic of capsular contracture (Fig. of MR imaging in this predominantly symptomatic patient population is 91%. MR imaging of the breast using a dedicated breast surface coil is clearly more accurate than either mammography or sonography in the evaluation of intracapsular rupture. Although mam- 2. Everson LI. Parantainen H, Detlie T, et al. Diagnosis of breast implant rupture: imaging findings and relative eflicacies of imaging techniques. AiR 1994:163: Gorcyzca DP. Sinha S. Ahn CY, et al. Silicone breast implants in siso: MR imaging. Radiolog 1992:185: ). A transverse diameter measuring less than two times the anterior-to-posterior depth of the implant corresponds to clinically evident contracture [11. Of the 345 implants evaluated, 100 showed evidence of repture on MR imaging. Of the 73 implants surgically removed thus far in this population, the prospective MR imaging interpretation has shown a sensitivity of 84% and specificity of 92% for the detection of mpture, both intra- and extracapsular. False-positive and false-negative examples have been proven (Figs. 1 1 and 12). The positive predictive value mography is sensitive for the detection of extracapsular rapture and siliconoma fomiation, MR imaging better defines the amount and location of extruded silicone. The role of MR imaging in screening asymptomatic women with implants is still undetermined. References I. Berg WA. Caskey CI, Hamper UM. et al. Diagnosing breast implant rupture with MR imaging, US and mammography. RadioGraphics 1993:13: Mund DF, Farria DM. Gorczyca DP. ci al. MR imaging of the breast in patients with silicone-gel implants: spectrum of findings. AiR 1993:161: Kessler DA. Special report: the basis of the FDA s decision on breast implants. N En,glJ Med 1992:326: Gorczyca DP. DeBruhl ND. Mund DF. Bassett LW. Linguini sign at MR imaging: does it represent the collapsed silicone implant shell? Radio!- ogy 1994:191: Monticciolo DL. Nelson RC. Dixon WT, Bostwick III. Mukundan S. Hester TR. MR detection of leakage fmm silicone breast implants: value of a siliconeselective pulse sequence.ajr 1994:163:51-56 AJR:167, November

6 This article has been cited by: 1. Laurent Lévy IRM et implants mammaires. Imagerie de la Femme 18:4, [CrossRef] 2. R. Ortega, I. Gómez de Travecedo, J.C. Hermoso Absceso mamario tardío tras la colocación de un implante. Clínica e Investigación en Ginecología y Obstetricia 33:5, [CrossRef] 3. Lisbet R. Hölmich, Ilse Vejborg, Carsten Conrad, Susanne Sletting, Joseph K. McLaughlin The diagnosis of breast implant rupture: MRI findings compared with findings at explantation. European Journal of Radiology 53:2, [CrossRef] 4. A Saunders, A M Davies, R J Grimer Magnetic resonance imaging of soft tissue expanders used in the management of musculoskeletal sarcomas. The British Journal of Radiology 71:849, [CrossRef]