Why Should We Use Ultrasound for Nail Evaluation

Nowadays, with the development of high- and ultra-high-resolution linear transducers, nail ultrasound has gained relevance in the identification of traumatic injuries, tumors, and inflammatory conditions, among others, providing useful information for clinical management, surgical planning, and monitoring disease inflammatory activity and effectivity of the treatment.

Which technical considerations do we need to keep in mind?

In all areas of dermatological ultrasound, the evaluation of the nail must be performed with a high-resolution linear transducer, ideally between 15 and 24 MHz, which allows for a perfect anatomical definition of all the components on the nail unit. It is expected to use enough gel between the transducer and the surface of the nail in order to be able to correctly see all the components of the nail (Figure 1), some authors have used other techniques such as immersing the nail in water or the use of pads, but in my practice I consider the first one to be more practical. It is always important to analyze in gray scale, Doppler, Duplex, and color; of course in axial and longitudinal view.

Figure 1. Adequate technic for nail ultrasound.

Ultrasound Anatomy of the Nail

The nail unit is made up of three main components: nail plate, nail bed, and matrix, as seen in Figure 2. Each of these has a precise sonographic definition. We also need to evaluate the periungual area compound for periungual folds. Furthermore, it’s important to include the distal phalanx, the distal interphalangeal joint, and the extensor tendon in the evaluation, mainly for inflammatory diseases such as psoriasis.

Figure 2A: Gray scale ultrasound longitudinal view of normal anatomy of a nail. Abbreviations: dp, dorsal plate; vp, ventral plate; nb, nail; m, matrix; npf, nail proximalfold.
Figure 2B: Color Doppler ultrasound longitudinal view of normal vascularization of the nail unit. Abbreviations: nb nail; pnf, proximal nail proximal fold; ipj, interphalangeal joint.

Why use ultrasound in the nail unit for inflammatory diseases?

The clinical findings of inflammatory nail diseases such as psoriasis, lichen, scleroderma, arthritis, and lupus may be very similar and difficult to differentiate. The use of biopsy leads to scarring and deformation of the nail. The morphological changes shown on ultrasound for these diseases are very characteristic, and, with adequate clinical correlation, we can avoid the use of biopsy. In psoriasis for example, five sonographic stages are described for the identification of the stage of the disease, and we have the ability to monitor the inflammatory activity by using Doppler evaluation and analyze the distal enthesis of the extensor tendon and synovial proliferation in the interphalangeal space. This is very important to develop early findings of psoriatic arthritis, even in subclinical stages, and this information can be crucial for the prognosis and treatment of patients.

Why use nail ultrasound in tumors?

Most nail tumors (73%) are ungular tumors and 27% are periungual. Ultrasound can show the classic appearance of multiple tumors to allow a clear diagnosis and information for surgical planning and treatment. Some studies have shown that ultrasound can change the clinical diagnosis in 35% of cases. For glomus tumors or exostoses, ultrasound can have a specificity of 100% (Figure 3).

Figure 3A: Ultrasound greyscale, longitudinal view shows well-defined hyperechoic nodule with scalloping of the bone margin of the distal phalanx.
Figure 3B: Color Duplex ultrasound (longitudinal view) shows hypervascularity within the nodule.

Why use nail ultrasound for trauma?

The nail unit is very prone to micro and macro-trauma. Micro-trauma can produce dystrophic changes in the nail plate that can simulate other nail diseases such as onychomycosis or nail psoriasis, retronychia and onychomadesis, being able to differentiate them adequately with ultrasound (Figure 4). In macro-trauma, fragmentation of the plate, hematomas, and even fractures of the distal phalanges can be diagnosed.

Figure 4A: Gray scale ultrasound longitudinal view. The arrow indicates a big fragment of retronychia with thickening of the proximal nail fold.
Figure 4B: Gray scale ultrasound longitudinal view with Onychomadesis. There are two fragments of the nail plate.

As we can see, ultrasound can give us sufficient and very clear information on all the components of the nail unit. Nail ultrasound may be more widely available than other diagnostic tools like MR, it also has more spatial resolution and there is no need for contrast. Of course, ultrasound nail evaluation should be performed following the technical recommendations for Dermatological ultrasound, and the study needs to be performed by a qualified individual with training and knowledge of nail pathology, which can be very challenging. In that scenario, it can be considered the first-line modality to clear up multiple nail pathologies.

References

Aluja Jaramillo F, Quiasúa Mejía DC, Martínez Ordúz HM, González Ardila C. Nail unit ultrasound: a complete guide of the nail diseases. J Ultrasound 2017; 20:181–192. doi:10.1007/s40477-017-0253-6

González CP. Ultrasonido de alta resolución en enfermedades benignas de la piel. Revista De La Asociación Colombiana De Dermatología Y Cirugía Dermatológica 2018; 26:230–239. doi.org/10.29176/2590843X.124

Kromann CB, Wortsman X, Jemec GBE. High-Frequency Ultrasound of the Nail. In: Humbert P, Maibach H, Fanian F, Agache P (eds). Agaches Measuring the Skin. Springer, Cham; 2015.

Wortsman X, Alfageme F, Roustan G, et al. Guidelines for performing dermatologic ultrasound examinations by the DERMUS Group. J Ultrasound Med 2016; 35:577–580.

Claudia Gonzalez, MD, is a Radiologist at Rosario University in Bogota, Colombia, is Vice Chair of the Dermatologic Ultrasound AIUM Interest Group, and has a Private Practice for high-resolution dermatological and MSK ultrasound in Bogotá, Colombia.

Interested in reading more about POCUS medical education? Check out these posts from the Scan:

Dermatologic Ultrasound: Skin Deep Knowledge

According to the recent European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) Position Statement on Dermatologic Ultrasound,1 dermatologic ultrasound is the application of ultrasound to the diagnosis of skin and appendages (hair and nails) diseases, as well as their healthy state, and cosmetic alterations.

This application was born as a necessity to answer challenges in dermatology that could not be addressed with superficial exploration methods such as clinical inspection, wood lamp, or dermoscopy, which mainly offer 2D views of the skin. The possibility of adding a third dimension (depth) and even a 4th one (with Doppler or dynamic explorations) with ultrasound makes dermatologic ultrasound a new way to go from guessing what’s happening below the surface to “seeing” what is really happening.

Ultrasound follow-up of intralesional glucantime injection in a cutaneous leishmaniasis. a) Clinical before treatment, b) B-mode before treatment, c) Color Doppler before treatment, d) Clinical after 3 injections, d) B-mode after 3 injections, d) Color Doppler after 3 injections.

During my years of clinical practice incorporating ultrasound in dermatology, I have heard some questions that always seem to arise in meetings. These are some of them:

What are the technical requirements for quality dermatologic ultrasound?

Although equipment with 70 MHz can be helpful to elucidate very concrete aspects of skin pathology, most questions and clinical situations in dermatology can be addressed today with high-quality conventional equipment above 15 MHz with color Doppler.

Apart from high-quality equipment, having a deep knowledge of dermatology, basic ultrasound, and its physical principles is the key to performing appropriate explorations in dermatologic ultrasound.

Which are the main fields of dermatologic ultrasound?

The fields at the forefront of dermatologic ultrasound are skin oncology, inflammatory skin diseases, and cosmetic dermatology.

How can dermatologic ultrasound help us dermatologist in skin oncology?

Skin cancer is the most frequent cancer in the human body. Most malignant skin tumor prognosis and treatment rely on depth and structural invasion, therefore, dermatologic ultrasound is an essential tool compared with MRI or CT in these kinds of evaluations, mainly because of its higher resolution and availability.

Is dermatologic ultrasound helpful in inflammatory skin diseases?

Deep inflammatory skin diseases such as hidradenitis suppurativa and morphea and sclerosing diseases usually do not have clear superficial expression. Dermatologic ultrasound is a key tool for in-depth evaluation of the inflammatory state of these diseases and is a guide for treatment and follow-up.

What are the main applications of dermatologic ultrasound in cosmetic dermatology?

Detection of dermal fillers and the complications and adverse reactions of these medical devices is essential in the management of a responsible cosmetic dermatology practice. Dermatologic ultrasound can also be an excellent tool for skin aging evaluation and anti-aging treatment evaluation.

Who is the AIUM and how can I learn Dermatologic Ultrasound from the AIUM?

The American Institute of Ultrasound in Medicine (AIUM) is the only scientific society that hosts a very active Dermatologic Ultrasound Community, which was funded in 2015 by Ximena Wortsman together with Orlando Catalano (present vice-chair of the community), Fernando Alfageme (present chair of the community and author of this post), and Claudia Gonzalez (secretary).

This community and their members are very active in AIUM meetings, hosting several scientific and didactic sessions, and has also produced some reference papers in dermatologic ultrasound.

The AIUM has hosted several sessions and workshops in AIUM meetings in the last 5 years with the collaboration of the dermatologic ultrasound community, although a need for structured teaching and learning is still necessary for those who are interested in this subspecialty.

Dermatology is an amazing application for ultrasound and it will be key in the near future for high quality, personalized skin medicine to foster the best, responsible care for our patients.


Fernando Alfageme, MD, is a Dermatologist and Chair of the Dermatologic Ultrasound Community (AIUM) as well as Codirector of the Ultrasound Learning Centre (Dermatology) at EFSUMB.

Reference

Alfageme F, Wortsman X, Catalano O, et al. European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) Position Statement on Dermatologic Ultrasound. Ultraschall Med. 2020 May 7. Online ahead of print. doi: 10.1055/a-1161-8872.

Complications of Cosmetic Fillers

Dermatologic Ultrasound—The first modality of choice in the diagnosis and management of complications due to the use of cosmetic fillers

Each day, the use of exogenous materials for aesthetic purposes (known as fillers) is more common. Recent data from the American Society of Plastic Surgery (ASPS) confirmed that it is the second most common noninvasive medical procedure, followed by the use of botulinum toxin.

It has been described that the ideal filler material must meet certain characteristics: be cosmetically effective, not allergenic or induce immunologic reactions, not carcinogenic, not teratogenic, not migrating, biocompatible, biodegradable, and injectable. When used routinely, the technique and the results should be reproducible. Finally, in addition to what is described, it must be cost effective.

Unfortunately, a substance that meets all of these characteristics does not yet exist and, therefore, it is possible that with the use of cosmetic fillers, multiple complications may appear, from very simple to severe disfigurement, irreversible sequelae, and even blindness or hemiparesis. To make the scenario even more difficult, complications can occur with medically approved substances such as hyaluronic acid or with substances not medically approved for cosmetic use such as silicone in oil.

Fillers can be injected by qualified physicians or nonphysicians and constitute a problem of malpractice. In my country, Colombia, this has become such a complex scenario, the complications derived from all these types of products and procedures have been considered a public health problem, and the situation may not be different in other countries of the world.

In many cases, complications can appear early or late, even many years after the filler application, and patients may not remember or even deny the use of them. Their clinical presentation is diverse and imprecise and can simulate multiple dermatologic pathologies. In this complex scenario, the precise diagnosis of these complications represents a clinical and imaging challenge.

Some diagnostic modalities, such as magnetic resonance imaging (MRI), have been used for the characterization of exogenous materials, mainly due to their excellent spatial anatomic resolution but, it is unable to establish precisely the type of substance injected. Although there are silicone suppression sequences, which in theory would allow differentiation of this substance from other types of fillers, the truth is that other types of fillers can have an appearance similar to silicone in MRI, which manifests as “silicone like”, being indistinguishable from each other or with multiple inflammatory skin conditions.

Computerized axial tomography does not have any indication in the identification of these types of substances and positron emission tomography (PET)-CT is not recommended for the evaluation of injectable material because the increase in metabolic activity is not specific and can be seen in patients with or without complications caused by the injection of the fillers.

High-resolution dermatologic ultrasound with linear transducers from 14- to 22-MHz has proven to be a very precise diagnostic tool to differentiate the type of filler injected and the complications derived from them, avoiding misdiagnosis and the use of unnecessary biopsies. Substances such as hyaluronic acid, calcium hydroxyapatite, silicone, polymethylmethacrylate, and polycaprolactone, among others, have a unique and characteristic ultrasound appearance that allows them to be easily differentiated from the others.

Late or early complications such as the development of dermatopathies, hypersensitivity reactions, migration of the filler material, inflammatory and noninflammatory nodules, can also be characterized with dermatologic ultrasound and the differentiation of these complications from diseases such as morphea, sarcoidosis, or cutaneous lymphoma that they may have an identical clinical presentation can be adequately performed by ultrasound. The study must be carried out by personnel with specific training and follow the suggested guidelines for the use of dermatologic ultrasound.

During my almost 10 years dedicated exclusively to dermatologic ultrasound, I have diagnosed many cases with all these types of complications related to the use of filler material, cases with mild complications or devastating stories of patients with sequelae that will mark your life forever. In all of them, ultrasound has provided valuable information with which my clinical colleagues, Dermatologists and Plastic Surgeons, have assertively managed their patients.

Bibliography

  • Worstman X. Identification and complications of cosmetic filler: sonography first. J Ultrasound Med 2015 Jul; 34(7):1163–1172. DOI: 10.7863/ultra.34.7.1163.
  • .Cavallieri F. Adventages of sonography in fillers and complications. In Image Guided Dermatologic Treatments. Switzerland. Springer 2020. pp93–102.
  • González C. High resolution ultrasound of soft tissues for characterization of fillers and its complications. Rev Colomb Radiol 2019; 30(1): 5064–5068
  • Worstman X, Alfagame F, Roustan G, Arias-Santiago S, Martorell A, Catalano O, Scotto M, Zarchi K, Bouer M, González C, Bard R, Mandava A, Gattini D. Guidelines for performing dermatologic ultrasound examinations by the DERMUS group. J Ultrasound Med 2016; 35: e111–e114.

Claudia Gonzalez, MD, is a radiologist at IDIME in Bogotá, Colombia, and is Secretary of the Dermatologic Ultrasound AIUM Interest Group, High Resolution Dermatological and MSK Ultrasound.

Interested in learning more? Check out the following posts from the Scan:

How I Became Involved in Dermatologic Ultrasound

There are certain moments in time when your gut tells you that your life is about to change. It happened to me in 1999.

I was on a training visit to the Musculoskeletal Ultrasound Section of the Department of Diagnostic Radiology at the Henry Ford Hospital in Detroit when Dr WortsmanI saw a “hockey stick” probe. Instinctively, I decided to use it on my fingernails. The images I saw on the screen were so fantastic that I ran to the library to see if there were any papers or publications that focused on ultrasound of the nail.

Surprisingly, I discovered a few Italian and Danish dermatologists who were working with smaller types of high frequency ultrasound devices on experimental settings. Wanting to learn more, I wrote to them. I was thrilled when Professor Gregor Jemec responded and agreed to collaborate.

However, getting an ultrasound machine for a dermatology project proved to be more difficult. It took almost 2 years before an ultrasound machine was installed and available for me to use while I was at the Department of Dermatology at Bispejerg Hospital in Copenhagen.

After securing the machine, I had the opportunity to scan dermatologic patients on a daily basis and I realized the great potential this imaging modality had within dermatology.

Once I returned to Chile, I really got to work. I studied the sonographic patterns, began to correlate the ultrasound images with the clinical and histologic findings, and started to publish the results.

That also proved difficult at first because radiology journals felt the content was better suited for dermatology journals and dermatology journals recommended radiology journals since the content involved imaging. Probably these journals had a difficult time even finding someone to review this material.

It was during this rough beginning that I reached out to my uncle Jacobo. I was telling him how difficult publishing could be and he simply reiterated President Truman’s famous quote, “If you can’t take the heat, get out of the kitchen.”

That just made me more committed. I created an educational website and continued to practice, learn, research, and write. In 2010, the Journal of the American Academy of Dermatology published our paper that analyzed more than 4,000 dermatologic ultrasound cases with histologic correlation. In 2013, our book Dermatologic Ultrasound with Clinical and Histologic Correlations was published.

Since that time, a lot has changed. I used to hear radiologists and dermatologists comment that they had never heard of dermatologic ultrasound. Now, the use of ultrasound in dermatology is expanding rapidly with colleagues from around the world using this tool to diagnose common dermatologic conditions earlier and more precisely.

For me, the dermatologic ultrasound journey mirrored my family’s immigration journey. We both left something familiar and ended up in a distant land. While the journey has not been easy, the results have been more than worthwhile.

But our work continues. Now, one of our challenges is how to share what we have learned to inspire and train a new generation of dermatologic ultrasound professionals. As a specialty, we are excited by AIUM’s support through the development of a dermatologic ultrasound interest group. Here we will share information, research, and resources. Please join us!

Why did you becoming interested in ultrasound? Have you participated in your AIUM Community? What struggles have you overcome in your career? Comment below or let us know on Twitter: @AIUM_Ultrasound.

Ximena Wortsman, MD, Radiologist, Chair of Dermatologic Ultrasound AIUM Interest Group, Senior Member of AIUM, Department of Radiology and Department of Dermatology, Institute for Diagnostic Imaging and Research of the Skin and Soft Tissues, Clinica Servet, Faculty of Medicine, University of Chile, Santiago, Chile.