What Is the Best Way to Assess Breast Implant Integrity?

Silicone breast implants are durable medical devices, but they are not lifetime devices. The implant shell can weaken or rupture over time, and the likelihood of rupture generally increases as an implant ages.

Importantly, most silicone implant ruptures are silent. There may be no obvious change in breast size, no pain and no abnormality detectable on physical examination. This means that imaging is often the only reliable way to determine whether an implant remains intact. The US Food and Drug Administration currently recommends that asymptomatic patients with silicone implants undergo their first ultrasound or MRI examination five to six years after implantation and then repeat imaging every two to three years. [1]

Published 10-year implant studies report rupture rates broadly in the order of approximately 6–10% per implant, although rates vary according to the implant model, patient group, method of surveillance and definition of rupture. Some older implant generations have substantially higher rupture rates. [2,3]

The important question is therefore not simply whether an implant should be assessed. It is:

Which imaging method provides the most reliable assessment of the entire implant and any silicone that may have escaped beyond it?

At MBR Health, where we have access to spectral CT, dedicated breast MRI and high-resolution ultrasound, our practical hierarchy for a comprehensive silicone implant integrity assessment is:

1. Dedicated silicone-sensitive spectral CT

2. A properly performed breast implant MRI

3. Dedicated breast and axillary ultrasound

This hierarchy reflects our experience with all three technologies, the reproducibility of the examination and the ability to assess silicone beyond the immediate breast.

Current international guidelines continue to identify MRI as the conventional reference examination, with ultrasound accepted for surveillance in asymptomatic patients. Published comparative research has found dual-energy or spectral CT to perform similarly to MRI rather than proving that it is universally superior. Our preference for spectral CT is based on the additional material-specific information and anatomical coverage available from a dedicated modern spectral CT protocol.

Why Assessing Implant Integrity Can Be Difficult

A silicone implant rupture can take several forms.

An intracapsular rupture occurs when the implant shell breaks but the silicone remains contained within the fibrous capsule that the body has formed around the implant. The breast may continue to look and feel normal.

An extracapsular rupture occurs when silicone escapes beyond that capsule into the surrounding breast or chest wall tissues.

Silicone may also travel through lymphatic channels into the regional lymph nodes. It can be found in the axillary lymph nodes beneath the arm, the internal mammary lymph nodes beside the sternum and, in some cases, more central lymph nodes within the chest.

A useful implant assessment should therefore answer more than one question:

• Is the implant shell intact?
• Is there silicone outside the shell?
• Is there silicone outside the surrounding capsule?
• How far has the silicone travelled?
• Is silicone present within regional lymph nodes?
• Are there associated fluid collections, inflammation, masses or capsular abnormalities?

The ability to answer all of these questions depends heavily on the imaging technology, the protocol used and the experience of the radiologist.

1. Spectral CT: Material-Specific Imaging of Silicone

Spectral CT is fundamentally different from ordinary CT.

A conventional CT scan measures how strongly tissues absorb or attenuate X-rays. The difficulty is that silicone and some normal soft tissues can have similar appearances on a standard CT image. Small deposits of silicone may therefore be difficult to separate from breast tissue, scar tissue, lymph nodes or surrounding structures.

Spectral CT collects information about how materials behave at different X-ray energy levels. Different substances change their attenuation in different ways as the energy changes. This creates a recognisable spectral response based on the material’s physical and atomic composition.

Silicone has a sufficiently distinct spectral response that advanced material-decomposition software can identify it and produce a dedicated silicone density map.

In practical terms, the Spectral CT is not relying only on shape or brightness. It is analysing the material itself.

Silicone can then be highlighted separately from normal soft tissue, allowing the radiologist to look for:

• silicone outside the implant shell
• extracapsular leakage
• small deposits within the breast or chest wall
• silicone within axillary lymph nodes
• silicone within internal mammary or mediastinal lymph nodes
• the full anatomical extent of silicone migration

Radiology research has demonstrated that silicone can have a strong dual-energy signal and that material-specific CT images can distinguish silicone from surrounding soft tissues that may look similar on conventional CT images. [4,5]

In a prospective comparison involving 46 patients, dual-energy CT and breast MRI performed similarly for detecting intracapsular rupture, extracapsular rupture and silicone within regional lymph nodes. The measured diagnostic performance was numerically slightly higher for CT in several categories, although the differences did not reach statistical significance. [6]

Why the Field of View Matters

A further advantage of spectral CT is its ability to examine a broad anatomical area during a single acquisition.

The assessment does not necessarily stop at the outer margin of the breast. Depending on the protocol, the radiologist can assess the chest wall, axillary regions, internal mammary chains and central chest for silicone migration.

This becomes particularly valuable when the clinical question is not simply, “Is the implant ruptured?” but, “Where has the silicone gone?”

At MBR Health, our dedicated spectral CT protocol is therefore our preferred and most comprehensive examination when the priority is maximum sensitivity to silicone and broad assessment of its anatomical distribution.

The Limitation: Radiation

Spectral CT uses ionising radiation. MRI and ultrasound do not.

That radiation burden must be justified, particularly in younger patients and where repeated surveillance examinations may be required. Spectral CT should not automatically be selected for every asymptomatic person simply because the technology is available.

The protocol, the patient’s age, symptoms, implant age, prior imaging and the need to assess possible silicone migration should all be considered. Where avoiding radiation is the overriding priority, a technically excellent MRI may be more appropriate.

2. Breast MRI: Excellent When the Correct Sequences Are Used

Breast MRI has traditionally been regarded as the reference imaging method for assessing silicone implant integrity.

3T MRI can demonstrate characteristic signs of intracapsular rupture, including silicone trapped between layers of the implant shell or a collapsed shell floating within the implant contents. It can also demonstrate extracapsular silicone within the surrounding tissues.

However, the words breast MRI do not describe one uniform examination.

An MRI performed primarily for breast cancer assessment is not necessarily the same as an MRI specifically designed to assess silicone implants. Implant imaging requires carefully selected sequences that distinguish:

• silicone
• water
• fat
• implant shell
• surrounding fluid and soft tissue

Silicone-sensitive sequences, water suppression and appropriate chemical-shift techniques are essential. Published breast MRI guidance specifically notes that evaluation of implants requires sequences designed to visualise silicone while suppressing water signal. [7,8]

Sequence quality matters because normal implant folds can mimic rupture, while subtle rupture can be missed when spatial resolution, suppression techniques or anatomical coverage are inadequate.

A well-performed implant MRI is excellent. A generic or poorly designed MRI examination is not equivalent.

Published sensitivity estimates for MRI vary considerably, broadly ranging from approximately 64% to 100%, with specificity also varying according to the study population, imaging protocol, implant generation and reference standard. [9]

MRI has several advantages:

• no ionising radiation
• excellent soft-tissue contrast
• strong assessment of intracapsular rupture
• the ability to assess surrounding breast tissue
• suitability for repeated surveillance

Its disadvantages include cost, examination time, claustrophobia, movement artefact, contraindications in some patients and substantial variation in protocol quality between providers.

3. Ultrasound: Useful, Accessible, but More Variable

Ultrasound is widely available, relatively inexpensive and does not use radiation.

It can demonstrate recognised signs of implant rupture. These include the stepladder sign in intracapsular rupture and the snowstorm appearance of silicone within surrounding tissues or lymph nodes. Ultrasound can also assess peri-implant fluid, superficial breast abnormalities and accessible axillary lymph nodes.

In experienced hands, ultrasound can perform very well. A recent study comparing same-day ultrasound and MRI reported high ultrasound sensitivity and specificity for implant rupture and found ultrasound more sensitive than MRI for silicone deposits within the axillary lymph nodes in that particular cohort. [10]

That does not remove ultrasound’s fundamental limitations.

Ultrasound is a real-time examination performed manually by an operator. The result depends on:

• the experience of the sonographer
• the time allocated to the examination
• whether the entire implant is systematically assessed
• whether posterior implant surfaces can be visualised
• whether both breasts and both axillae are examined
• the transducer and machine quality
• the experience of the interpreting radiologist

Ultrasound also has a more restricted field of view. It examines one small region at a time and does not automatically provide the same broad, reproducible anatomical map as CT or MRI. Ultrasound literature consistently recognises that diagnostic accuracy varies with operator experience and scanning technique. [11,12]

Ultrasound is therefore a reasonable screening or targeted problem-solving examination, particularly where MRI or spectral CT is not available. However, when the question involves subtle intracapsular rupture, the posterior surface of the implant or the full extent of silicone migration, its efficacy is not consistently comparable with a dedicated spectral CT or technically excellent implant MRI.

Comparing Spectral CT, MRI and Ultrasound

Why Imaging Recommendations Can Differ Between Providers

Imaging advice is inevitably influenced by the equipment and expertise available at a particular clinic.

A provider with ultrasound may recommend ultrasound. A clinic with MRI may describe MRI as the definitive examination. A conventional CT provider does not have the hardware or software required to create silicone-specific spectral maps.

This does not necessarily mean that the advice is inappropriate. It does mean that availability should not be confused with an objective comparison of the technologies.

At MBR Health, we have access to all three modalities. This allows the examination to be selected according to the clinical question rather than according to which machine happens to be available.

Our hierarchy is based on:

• the ability to identify silicone directly
• assessment of the entire implant
• reproducibility between examinations
• assessment beyond the immediate breast
• visualisation of regional lymph nodes
• radiation considerations
• the individual patient’s circumstances

When Should Implant Integrity Be Investigated?

Imaging may be appropriate when there is:

• unexplained breast pain or tenderness
• a change in breast shape, size or firmness
• new asymmetry
• a palpable lump
• capsular contracture
• swelling or a peri-implant fluid collection
• enlarged or abnormal axillary lymph nodes
• previous trauma
• concern regarding an older implant
• an uncertain or incomplete previous ultrasound
• planned implant revision or removal

Most silicone implant ruptures are silent, so the absence of symptoms does not guarantee that an implant remains intact.

Sudden swelling, a rapidly enlarging breast, a new peri-implant mass or unexplained lymph-node enlargement requires appropriate medical assessment. Implant rupture is not the only possible complication, and the imaging protocol may need to assess for infection, inflammation or an implant-associated malignancy.

So, What Is the Best Scan for Silicone Breast Implant Integrity?

For the most comprehensive assessment available at MBR Health, our hierarchy is:

1. Dedicated spectral CT

Our preferred examination where the priority is sensitive silicone detection, broad anatomical coverage and mapping of silicone within the breast, chest wall and regional lymph nodes.

2. Properly performed breast implant MRI

An excellent radiation-free alternative, provided that dedicated silicone-sensitive sequences and appropriate anatomical coverage are used.

3. Dedicated breast and axillary ultrasound

A useful, accessible and radiation-free examination, but more dependent on operator skill and less comprehensive because of its limited field of view.

The correct examination is not always the most technologically advanced examination. It is the examination that answers the clinical question with the greatest accuracy while balancing cost, access, radiation and the individual patient’s circumstances.

The central principle is simple:

Implant integrity should be assessed using the best available imaging protocol—not simply the modality a provider happens to offer.

Author: Dr Kirralee Sherif (PhD)

Related Articles

• Spectral CT for Breast Cancer: A Clinical Discussion over Detection, Diagnosis and Surveillance
• CT vs MRI Explained: Differences, costs and Medicare Coverage
• Why Choose Spectral CT over Regular CT

Frequently Asked Questions

For additional frequently asked questions please visit our FAQs page.

Can a silicone breast implant rupture without symptoms?

Yes. Most silicone implant ruptures are silent and may not produce pain, visible breast changes or an abnormal physical examination. Imaging may be the only way to detect them.

Can silicone travel into lymph nodes?

Yes. Escaped silicone can migrate through lymphatic pathways and may be seen within axillary, internal mammary or other regional lymph nodes. Spectral CT can produce material-specific maps that help distinguish silicone from surrounding nodal tissue.

Is ultrasound enough to rule out implant rupture?

Ultrasound may be sufficient in some patients, particularly when performed by an experienced breast-imaging team. However, a negative ultrasound may not be definitive where the examination is technically limited, the posterior implant cannot be completely assessed or there is concern regarding more extensive silicone migration.

Does spectral CT use contrast?

A dedicated spectral CT examination for silicone implant integrity can be performed without intravenous contrast. Contrast may be required when there is a separate question regarding breast tissue, inflammation, a mass or another chest abnormality. The protocol should be determined by the radiologist.

How often should silicone implants be checked?

The FDA recommends an initial assessment five to six years after silicone implant surgery and repeat assessment every two to three years. Earlier investigation may be required when symptoms or other concerns are present. [1]

References

1. US Food and Drug Administration. Risks and complications of breast implants: silicone gel-filled implant rupture.

2. Maxwell GP, Van Natta BW, Bengtson BP, Murphy DK. Ten-year results from the Natrelle 410 anatomical form-stable silicone breast implant core study. Aesthet Surg J. 2015 Feb;35(2):145-55. doi: 10.1093/asj/sju084. Erratum in: Aesthet Surg J. 2015 Nov;35(8):1044. doi: 10.1093/asj/sjv172. PMID: 25717116; PMCID: PMC4399443.

3. Spear SL, Murphy DK; Allergan Silicone Breast Implant U.S. Core Clinical Study Group. Natrelle round silicone breast implants: Core Study results at 10 years. Plast Reconstr Surg. 2014 Jun;133(6):1354-1361. doi: 10.1097/PRS.0000000000000021. PMID: 24867717; PMCID: PMC4819531.

4. Johnson TR, Himsl I, Hellerhoff K, Mayr D, Rjosk-Dendorfer D, Ditsch N, Krauss B, Friese K, Reiser MF, Lenhard MS. Dual-energy CT for the evaluation of silicone breast implants. Eur Radiol. 2013 Apr;23(4):991-6. doi: 10.1007/s00330-012-2667-z. Epub 2012 Oct 13. PMID: 23064715.

5. McCollough CH, Leng S, Yu L, Fletcher JG. Dual- and Multi-Energy CT: Principles, Technical Approaches, and Clinical Applications. Radiology. 2015 Sep;276(3):637-53. doi: 10.1148/radiol.2015142631. PMID: 26302388; PMCID: PMC4557396.

6. Glazebrook KN, Doerge S, Leng S, Drees TA, Hunt KN, Zingula SN, Pruthi S, Geske JR, Carter RE, McCollough CH, Fletcher JG. Ability of Dual-Energy CT to Detect Silicone Gel Breast Implant Rupture and Nodal Silicone Spread. AJR Am J Roentgenol. 2019 Apr;212(4):933-942. doi: 10.2214/AJR.18.20138. Epub 2019 Feb 19. PMID: 30779664.

7. Mann RM, Kuhl CK, Kinkel K, Boetes C. Breast MRI: guidelines from the European Society of Breast Imaging. Eur Radiol. 2008 Jul;18(7):1307-18. doi: 10.1007/s00330-008-0863-7. Epub 2008 Apr 4. PMID: 18389253; PMCID: PMC2441490.

8. Shah M, Tanna N, Margolies L. Magnetic resonance imaging of breast implants. Top Magn Reson Imaging. 2014 Dec;23(6):345-53. doi: 10.1097/RMR.0000000000000039. PMID: 25463409.

9. Expert Panel on Breast Imaging:; Lourenco AP, Moy L, Baron P, Didwania AD, diFlorio RM, Heller SL, Holbrook AI, Lewin AA, Mehta TS, Niell BL, Slanetz PJ, Stuckey AR, Tuscano DS, Vincoff NS, Weinstein SP, Newell MS. ACR Appropriateness Criteria^® Breast Implant Evaluation. J Am Coll Radiol. 2018 May;15(5S):S13-S25. doi: 10.1016/j.jacr.2018.03.009. PMID: 29724416.

10. Spit KA, Azahaf S, de Blok CJM, Duvivier KM, Wiebenga OT, Nanayakkara PWB. Ultrasound versus MRI for evaluation of silicone leakage from silicone breast implants. Heliyon. 2024 Jun 19;10(12):e33325. doi: 10.1016/j.heliyon.2024.e33325. PMID: 39022001; PMCID: PMC11253520.

11. Hillard C, Fowler JD, Barta R, Cunningham B. Silicone breast implant rupture: a review. Gland Surg. 2017 Apr;6(2):163-168. doi: 10.21037/gs.2016.09.12. PMID: 28497020; PMCID: PMC5409893.

12. Juanpere S, Perez E, Huc O, Motos N, Pont J, Pedraza S. Imaging of breast implants-a pictorial review. Insights Imaging. 2011 Dec;2(6):653-670. doi: 10.1007/s13244-011-0122-3. Epub 2011 Aug 7. PMID: 22347984; PMCID: PMC3259319.