How do I know if I have biopolymers? Which test detects them and what it shows

The question almost everyone arrives with is “how do I know whether I have biopolymers?”. But when the material has been in place for years, that is usually the easy part. The questions that really change the plan are three others: how much there is, exactly where it is and what state the surrounding tissue is in.

And only an imaging test answers those three.

This page explains which test is used, what shows on it, what no image can tell you, and one thing almost nobody warns about that may save you a bad fright: that injected material can confound other medical tests you have in the future.

If you still do not know what you were given, start with what substances lie behind the word “biopolymer”. The whole process is in the guide to biopolymer removal.

MRI: the reference test

It is the one that best answers the three questions that matter. MRI gives the overview: where the material is, how much there is and how far it has travelled, as well as the state of the surrounding tissue. That is why it is the one requested when decisions have to be taken, and when surgery is on the table it is the indispensable test.

With contrast or without: they are not the same

It is a distinction almost nobody explains and which decides what the test is good for, because each mode answers a different question:

• Without contrast is the one that shows the material: where it is, how much there is and which planes it has spread through. It is the one we usually request, because it is the one that answers what a surgical plan needs.
• With contrast is the one that shows the inflammation: it helps assess how much the surrounding tissue is reacting.

So there is no single answer to “with contrast or without?”. One or the other is requested according to what has to be answered in your case: if the question is how much product there is and where it is, without contrast; if the question is how inflamed the tissue is, with contrast. If you have had one and are left with the other question, it does not mean the test was wrongly requested: it means it was requested for something else.

In a case published in 2025 of severe complications from biopolymers, the MRI showed the foreign material accompanied by signs of severe inflammation of the surrounding tissue, and the subsequent biopsy confirmed foreign body granulomas with a morphology described as “Swiss cheese”.

And when surgery is on the table, imaging stops being a diagnosis and becomes a working plan. In a case published in 2026 of refractory inflammatory nodules after several injections of different materials, imaging — MRI, supported by high-frequency ultrasound — made it possible to map the lesions precisely and to guide the surgical excision. That is MRI’s real role: not just knowing, but planning.

Ultrasound: the initial approach, and the one that can point to the material

Ultrasound is a good first approach — it is accessible, quick and involves no radiation — and it has one virtue MRI does not: with aesthetic filler materials, it can point to what the material is.

A 2026 review of high-frequency ultrasound applied to fillers describes how different materials do not look the same, and how those differences allow a provisional identification. Among the patterns described:

• Hyaluronic acid appears as well-defined pseudocystic areas, anechoic or hypoechoic — that is, as dark pockets.
• Calcium hydroxyapatite shows as irregular hyperechoic deposits with marked posterior acoustic shadowing.
• Methacrylate (PMMA) shows hyperechoic foci with a characteristic comet-tail artefact.
• Polycaprolactone appears as hypoechoic material with scattered hyperechoic foci, which correspond to the microspheres.
• Poly-L-lactic acid shows as hyperechoic deposits under the skin in the period following injection.

That same review notes that ultrasound also allows complications — nodules, granulomatous reactions, vascular compromise — to be detected in real time and targeted procedures to be guided.

That said, with an honest qualification: those patterns are described for aesthetic filler materials. When what was injected was industrial-grade silicone or an unidentified mixture, ultrasound remains useful for locating it and for seeing the state of the tissue, but it does not turn a suspicion into a name. And for finding out how much there is and how far it reaches, MRI is still what governs.

The material moves, and that is only visible on imaging

One of the reasons imaging is not optional in serious cases is that the material is not always where it was injected.

Silicone injected for cosmetic purposes has been described migrating at a distance and affecting lymph nodes. In a case published in 2025, material injected into the breast and buttocks had migrated through the inguinal ligaments as far as the labia majora. And an association between gluteal biopolymers and aggressive synovitis of the hip joint has also been reported.

These are not the norm, and they should not be read as what is going to happen to you. They are the reason why, faced with symptoms that do not fit the treated area, we look beyond it.

⚠️ What you have to say before any test

This is the most important part of the page and the one almost no site mentions.

Injected material causes chronic inflammation, and that inflammation takes up on metabolic scans. In a case published in 2025, a patient with cosmetic silicone in the breasts and buttocks had extensive areas of uptake and axillary, mediastinal and abdominopelvic lymph nodes taking up, in a setting where a breast cancer was being investigated. The authors describe it plainly: silicone can produce false positives for nodal involvement and for distant metastasis.

Translated into what matters to you: if you ever have a mammogram, an ultrasound, an MRI or a PET/CT, say that you have injected material, where and since when, even if it seems beside the point. It can save an unnecessary biopsy, weeks of fright or a mistaken diagnosis.

What no image is going to tell you

So that you do not come out of the scan expecting something it does not give:

• It does not give the brand name of what you were injected with.
• It does not say how much can be removed. That is decided in theatre, with the tissue in front of us.
• It does not predict whether you will have complications. It describes the present, not the future.
• It does not replace the examination. What can be felt and what you tell us still count.

Can the material not be analysed when it is removed?

It is the logical question: if the product comes out in theatre, why not send it for analysis and settle the doubt? The honest answer is that in routine practice it is not done, and it is worth explaining why, because “it is not done” and “it cannot be done” are not the same thing.

A conventional biopsy does not put names to things. What histopathology demonstrates is the reaction: foreign body granulomas, giant cells, fibrosis. It confirms that there is foreign material and how the tissue is responding, which is useful clinical information, but it does not identify the specific product.

Identifying it requires materials-laboratory techniques, not histopathology. And they exist, they are published and they work:

• In a 2013 study a database of the infrared spectra of commercial fillers was built first, and then the tissue of seven patients with severe complications from unknown products was analysed — two granulomas, two infiltrated tissues and three abscesses. By comparing the absorption bands of the diseased tissue with that reference database it was possible to identify the injected filler.
• In a case published in 2015, Raman spectroscopy on an excised nodule identified methacrylate from its characteristic peaks, after confocal microscopy on the fresh specimen had shown the microspheres.

So why is it not done routinely? For three reasons worth knowing:

1. They are small studies. The 2013 one is explicitly a pilot study of seven patients, and the 2015 one is a single case. There is no validated protocol or established clinical pathway.
2. You need a reference database to compare against. And there is the practical limit, precisely in the cases that concern us most: if what was injected was industrial-grade silicone or a home-made mixture, there is no commercial product to match the spectrum against. The technique works best exactly where it is least needed.
3. It almost never changes what is done. The plan is decided by the quantity, the area, the state of the tissue and the symptoms. Knowing whether the material is a silicone or a methacrylate is valuable information — the authors themselves stress its medico-legal interest — but it rarely changes the surgery that has to be done.

All that said, it is a field that is moving, and the interesting direction is non-invasive. A 2021 study measured the MRI relaxation times of silicone, collagen and hyaluronic acid and found that they differ from each other; in two patients with known silicone, the quantitative sequence identified it correctly. It is preliminary — three patients — but it suggests MRI itself may end up saying something about what it is, and not only about how much and where.

In the meantime, the practical answer remains the one above: imaging says how much, where and in what state. The name of the product, almost never.

Frequently asked questions

Which test will they order, an ultrasound or an MRI?

At ICPM the test usually requested is an MRI without contrast, because it is the one that most faithfully reflects where the product is, how much there is and how far it reaches. Ultrasound is a good initial approach and gives superficial detail, but it does not replace MRI when a plan has to be made.

Can you tell how much biopolymer I have?

The extent and the planes involved can be estimated, which is what is useful for planning. An exact volume in millilitres is not something imaging gives reliably.

Is it any use for finding out what substance it is?

It points. Among aesthetic filler materials, each has a characteristic ultrasound appearance. With industrial silicone or unidentified mixtures, imaging locates and assesses, but it does not put a name to it. Nor does what is removed at surgery: the extracted material is not sent for analysis routinely.

Will what they take out at surgery be analysed?

Not routinely. The removed material is not sent for analysis in routine practice, and histopathology, when it is done, demonstrates the foreign body reaction but does not identify the product. There are laboratory techniques that can identify it — infrared spectroscopy, Raman — but they are small studies, they need a reference database to compare against and they almost never change the treatment.

Will they order the MRI with or without contrast?

It depends on what has to be answered. Without contrast shows the material — where it is, how much there is, which planes. It is the one we usually request. With contrast gives a better assessment of the inflammation in the surrounding tissue. One or the other is requested according to the case.

Do I need tests if I have no symptoms?

It is not automatic. It is assessed according to the area, the quantity, the time elapsed and what the examination finds. That decision is set out in remove or monitor.

They found lymph nodes on a scan — could it be because of this?

It could. Injected material is described as causing uptake in lymph nodes and mimicking distant disease. It is essential that whoever interprets the scan knows you have injected material.

Is an MRI dangerous if I have biopolymers?

An MRI does not act on the injected material in the way people fear. What matters is not avoiding the scan, but the radiologist knowing what they are looking at.

Can I bring tests done elsewhere?

Yes, and it helps a great deal. If you have had an ultrasound or an MRI, bring it with the images and the report, not just the report.

And if the scan comes back “normal”?

It can happen, especially with a small amount of material or a long time elapsed. A scan with no striking findings does not cancel out what you tell us or what can be felt: it is assessed as a whole.

Sources

• Tang Y, Wang Z, Bi M, Jia Y. Clinical Applications of High-Frequency Ultrasound in Filler Identification and Complication Management. Semin Ultrasound CT MR. 2026. Describes the characteristic ultrasound features of the various filler materials — hyaluronic acid as well-defined anechoic or hypoechoic pseudocystic areas; calcium hydroxyapatite as irregular hyperechoic deposits with posterior acoustic shadowing; methacrylate as hyperechoic foci with a comet-tail artefact; polycaprolactone as hypoechoic material with scattered hyperechoic foci; poly-L-lactic acid as early subcutaneous hyperechoic deposits — and the role of ultrasound in detecting complications and guiding procedures. https://pubmed.ncbi.nlm.nih.gov/42342087/
• Wang H, Lo C, Wang Z, Huang PP, Qiu H. Refractory craniofacial soft-tissue foreign-body granulomas after sequential multi-material filler injections: Imaging-based surgical management and filler-associated clinicopathologic analysis. J Craniomaxillofac Surg. 2026. Late inflammatory nodules after successive injections of different materials, with a poor response to intralesional corticosteroid and aspiration; high-frequency ultrasound and MRI allowed the lesions to be mapped precisely and guided the surgical excision; histopathology showed retained particulate material with foreign body giant cells, granulomatous inflammation and collagen-rich fibrosis. https://pubmed.ncbi.nlm.nih.gov/42551060/
• Huo B, Tso R, Shen L, Mansberg R. Confounding diagnosis of metastatic disease on FDG PET/CT due to cosmetic liquid silicone administration in breasts and gluteal regions with silicone migration to labia majora. Radiol Case Rep. 2025. Cosmetic injections of liquid silicone can produce inflammation, chronic mastitis, distant migration and lymphadenitis, and give rise to false positives for nodal involvement and distant metastasis; in the case described the material migrated through the inguinal ligaments as far as the labia majora. https://pubmed.ncbi.nlm.nih.gov/40895000/
• Hormaza-Jaramillo A, Peñaloza Gonzalez D, Benavides-Ibarra SA, et al. Severe Complications Due to Biopolymers in a Patient With Autoimmune Disease: A Case Report and Review of the Literature. Aesthet Surg J Open Forum. 2025;7. MRI showed exogenous material with signs of severe inflammation of the surrounding tissue and the biopsy was consistent with foreign body granulomas with a “Swiss cheese” morphology. https://pubmed.ncbi.nlm.nih.gov/40979311/
• Persichetti P, Palazzolo D, Tenna S, Poccia I, Abbruzzese F, Trombetta M. Dermal filler complications from unknown biomaterials: identification by attenuated total reflectance spectroscopy. Plast Reconstr Surg. 2013;131:597e-603e. A pilot study: a database of the infrared spectra of commercial fillers was built and then pathological tissue from seven patients with severe complications from unknown fillers was analysed — two granulomas, two infiltrated tissues and three abscesses; comparing the absorption bands with the reference database made it possible to identify the injected filler; the authors note its usefulness for choosing treatment and for medico-legal purposes. https://pubmed.ncbi.nlm.nih.gov/23542278/
• Cinotti E, Perrot JL, Labeille B, et al. Identification of a soft tissue filler by ex vivo confocal microscopy and Raman spectroscopy in a case of adverse reaction to the filler. Skin Res Technol. 2015;21:114-118. A single case: reflectance confocal microscopy on the fresh specimen showed hyporeflective microspheres in the dermis and Raman spectroscopy confirmed methacrylate from its characteristic peaks; the authors present them as tools complementary to conventional histopathology. https://pubmed.ncbi.nlm.nih.gov/25066771/
• Niasme E, Delattre BMA, Lenoir V, Modarressi A, Poletti PA, Becker M, Boudabbous S. Quantitative magnetic resonance imaging: differentiating soft tissue implants and fillers used in cosmetic and reconstructive surgery. Skeletal Radiol. 2021;50:231-237. Silicone, collagen and hyaluronic acid showed different relaxation times ex vivo at 1.5 and 3 T; in three patients with complications from gluteal filler, the quantitative sequence correctly identified silicone in the two known cases; the authors conclude that quantitative sequences have potential for differentiating filler types non-invasively. https://pubmed.ncbi.nlm.nih.gov/32761256/
• Llinás A, Bonilla G, Barrios V, Sadlik G, Gómez-Ortega V. Gluteal biopolymers and aggressive synovitis of the hip joint: A new reported association. J Plast Reconstr Aesthet Surg. 2022;75(2). Reports the association between gluteal biopolymers and aggressive synovitis of the hip joint. https://pubmed.ncbi.nlm.nih.gov/34844884/

Book your consultation

If you suspect you are carrying injected material and do not know how much or where, the assessment starts there: examining the area and, when the product needs mapping, requesting an MRI without contrast, which is the one that genuinely answers those questions.

If you already have scans, bring them with the images. And if you are under follow-up for anything else, make sure that team knows you have injected material.

Clinical confirmation by the surgeon

Dr Enrique Salmerón González

Specialist in Plastic, Aesthetic and Reconstructive Surgery
Registration no. 46/4624077

Dr Elena García Vilariño

Specialist in Plastic, Aesthetic and Reconstructive Surgery
Registration no. 46/4624503

Last reviewed: 6 September 2026. This content is for information only and does not replace an individual assessment by a healthcare professional.