How to Start on Dermatologic Ultrasound: Basic Anatomical Concepts, Guidelines, Technical Considerations, and Best Tips

Ultrasound Pattern of Congenital Smooth Muscle Hamartoma of the Skin

Smooth muscle hamartoma (SMH) of the skin is a cutaneous benign proliferation of mature smooth muscle. Congenital SMH (CSMH) of the skin represents the most frequent type, and to date, there are no reports on its ultrasonographic pattern. A retrospective study of the color Doppler ultrasound (US) images of six CSMH patients at high and ultra-high frequencies was performed. Demographic data and US characteristics were analyzed. All cases presented a focal area of dermal thickening, decreased dermal echogenicity, and/or distorted dermal regions with prominent hair follicles. A total of 83.3% of cases showed no signs of internal vascularity at color Doppler imaging. Ultrasonographic features can support clinical diagnosis and follow-up of CSMH, which may potentially avoid biopsies.

High-Frequency Ultrasound Evaluation of the Nail Unit: Essential Insights for Clinicians

INTRODUCTION

High-frequency ultrasound (HFUS) has become increasingly prevalent in dermatological clinical settings over the past decade. However, understanding its appropriate indications and significant utility in onychology is not fully exploited. Based on a clinical self-assessment, the study aimed to provide fundamental recommendations regarding the applications, indications, and limitations of HFUS in nail disorders.

METHODS

A clinical practice assessment survey, comprising 15-item multiple-choice questions focused on nail unit ultrasound, was distributed online to clinicians' members of the Colombian Network of Research and Treatment for Nail Disorders (RITU), during the first quarter of 2024. Participation was voluntary and anonymous; no financial compensation was offered. Aggregated responses were analyzed confidentially.

RESULTS

Around 44 clinicians (86.4% dermatologists and 13.6% radiologists) participated in the study. While most acknowledged the value of HFUS in evaluating nail disorders, knowledge gaps were evident, particularly concerning optimal settings and proficiency maintenance. Despite the widespread use of HFUS, a gap in expertise was observed concerning its application in specific nail pathologies. Although HFUS was the preferred modality for many nail conditions, some concerns about its reliability suggest the need for further training to ensure confident and effective utilization.

CONCLUSION

This study revealed significant knowledge gaps among clinicians regarding the appropriate application of dermatologic ultrasound and other imaging modalities in the evaluation of nail disorders. The findings emphasize the value and specific indications for HFUS in assessing nail pathology, highlighting the need for enhanced training and education in this specialized area.

Advances in Skin Ultrasonography for Malignant and Benign Tumors of the Head and Neck: Current Insights and Future Directions

Ultrasound imaging has become an indispensable diagnostic tool across various medical fields. In recent years, there has been growing interest in the use of ultrasonography for the evaluation of skin lesions. However, scientific reports detailing the precise role of ultrasound in determining the morphology of malignant skin tumors still remain limited. Malignant skin lesions, particularly in the head and neck region-their most common location-pose significant challenges due to the complex anatomy of these areas. The primary treatment for non-melanoma skin cancers, including basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), is surgical excision. Mohs micrographic surgery is considered the gold standard due to its tissue-sparing approach and high cure rates. However, it is a time-consuming and resource-intensive procedure that is not always widely accessible. In contrast, standard surgical excision, while more widely available, often results in incomplete tumor removal, necessitating subsequent surgical radicalization or the use of adjuvant therapies. Routine ultrasound evaluation of both benign and malignant skin lesions could enhance early detection and facilitate timely treatment. However, the current body of evidence for the usage of skin ultrasound in presurgical evaluation is poor and lacks standardization. Given these challenges, in this review, we aim to highlight the potential value of preoperative skin ultrasonography in accurately assessing benign and malignant skin lesion dimensions and morphology.

Lip Volumization With Hyaluronic Acid: Comparative Ultrasonographic Evaluation of Cannula and Needle Techniques in a Multicenter Study

BACKGROUND

Lip volumization using hyaluronic acid (HA) is among the most popular aesthetic procedures due to the role of the lips in modern beauty standards. This study explored the ultrasound characteristics of HA deposits following injection using either cannula or needle techniques.

METHODS

A multicenter, descriptive study involving 27 patients from five aesthetic centers in Colombia, Spain, and Mexico was conducted. Ultrasound evaluations were performed pre- and post-procedure to assess anatomical changes, HA deposit morphology, and vascular mapping with Doppler. Patients were randomly assigned to either the cannula technique (11 patients, representing 41% of the cohort) or the needle technique (16 patients, representing 59% of the cohort). Satisfaction was measured using a subjective scale (1-5).

RESULTS

HA doses ranged from 0.4 to 1 cc. Among the 27 patients, 25 had a single type of deposit, while two patients presented with two different types simultaneously. Ultrasound examination revealed that 81% (22 patients) of labial arteries were located in the wet submucosa, 15% (four patients) in the dry submucosa, and 4% (one patient) intramuscularly. A total of nine patients presented with lip asymmetry, and two patients had lip hypotrophy; all 11 patients achieved correction, defined as the restoration of symmetrical lip volume and contour. Patient satisfaction was universally high, with 74% (20 patients) reporting complete satisfaction.

CONCLUSION

Ultrasound evaluation is an effective and safe method for assessing patients undergoing HA injections. Our observations indicate that injection techniques, whether using a needle or a cannula, influence the shape and location of HA deposits, with elongated deposits being more common with cannula use and round deposits predominantly associated with needle injections. Pre-procedure ultrasound allows for the identification of each patient's specific lip anatomy, aiding in injection planning, while post-procedure ultrasound helps verify the location of deposits and detect potential complications. These findings highlight the importance of careful technique selection and thorough anatomical assessment to optimize safety and aesthetic outcomes. Future research should focus on larger samples and long-term follow-up to validate these observations and further enhance procedural safety in aesthetic medicine.

High-Frequency and Ultra-High-Frequency Ultrasound in Dermatologic Diseases and Aesthetic Medicine

Dermatologic ultrasonography applications are rapidly growing in all skin fields. Thanks to very high spatial resolution, high-frequency and ultra-high-frequency ultrasound can evaluate smaller structures, allowing us to improve diagnosis accuracy and disease activity. Moreover, they can guide treatment, such as drug injection, and assess therapy efficacy and complications. In this narrative review, we evaluated high-frequency ultrasound and ultra-high-frequency ultrasound in infections, inflammatory dermatoses, metabolic and genetic disorders, specific cutaneous structure skin disorders, vascular and external-agent-associated disorders, neoplastic diseases, and aesthetics.

Validity and Advantages of Three-Dimensional High-Frequency Ultrasound in Dermatological Evaluation

Background/Objectives: High-frequency ultrasound (HFUS) has been reported to be useful for the diagnosis of cutaneous diseases; however, its two-dimensional nature limits the value both in quantitative and qualitative evaluation. Three-dimensional (3D) visualization might help overcome the weakness of the currently existing HFUS. Methods: 3D-HFUS was newly developed and applied to various skin tumors and inflammatory hair diseases to assess its validity and advantages for dermatological use. Results: Three-dimensional images were successfully obtained from skin tumors, including basal cell carcinoma, subungual squamous cell carcinoma, Bowen's disease, and malignant melanoma, as well as inflammatory hair loss diseases including alopecia areata in different disease phases and lichen planopilaris. Vertical and horizontal images were generated from the original 3D image data and assessed in comparison with histopathological and/or dermoscopic images. By additionally obtaining horizontal data, lateral tumor margins at any depth were visualized in tumors. In inflammatory hair loss diseases, signs potentially associated with disease activity and pathology were detected. In addition, horizontal evaluation helped grasp hair cycle status and hair follicle densities. Conclusions: These findings suggested that this novel technology holds promise as a robust noninvasive tool to diagnose and evaluate various cutaneous diseases.

Objective Noninvasive Measurement of the Volumizing Effect of a Dermal Filler: An In Vivo Study

BACKGROUND

Information about the volumizing effects of dermal fillers is critical for physicians' understanding of product features and prudent decision-making in clinical practice. It is important for material engineers to develop and optimize new dermal fillers, especially when comparing the physiochemical properties of a new product with those of existing fillers that are used worldwide.

OBJECTIVE

This study aimed to establish a reliable, noninvasive method for in vivo quantitative evaluation of the filling effect in order to predict possible effectiveness after filler injection and to evaluate the degradation trend over time.

METHODS

A rabbit model of ear injection with dermal fillers was established. Hyaluronic acid (HA) filler was injected into the subcutaneous layer of rabbit ears, resulting in a stable skin bulge. Ultrasonography was used to noninvasively measure the skin bulge for volume calculation; the volume change was analyzed periodically until 38 weeks. Pathological examination, the gold standard, was performed to confirm degradation.

RESULTS

The immediate volumizing effect of HA filler injection was macroscopically observed as a local skin bulge. Ultrasound was able to precisely detect the shape of the filler and calculate the length, width, and height of the skin bulge at each time point. The degree of uplift and amount of residual samples in the pathological evaluation were consistent with the results of morphological observation using ultrasound.

CONCLUSION

Evaluation of the volume impact of dermal filler through the rabbit ear injection model evaluation enables material science evaluation in the early stage of material development, and has certain clinical reference value.

LEVEL OF EVIDENCE I

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Ultrasound in Skin Cancer: Why, How, and When to Use It?

BACKGROUND

Skin cancer is the most common cancer in human beings. Ultrasound is a powerful and non-invasive imaging technique that has expanded its use in dermatology, including in the skin cancer field. The full range of critical anatomical information provided by ultrasound cannot be deduced from a naked eye examination, palpation, or other imaging techniques such as dermoscopy, confocal microscopy, magnetic resonance imaging, or PET-CT (Positron Emission Tomography-Computed Tomography).

METHODS

This review practically analyzes the main ultrasonographic features of the most common types of skin cancers and the performance of the locoregional staging according to the literature, which is illustrated by state-of-the-art clinical and ultrasonographic correlations.

RESULTS

The most common types of skin cancer show recognizable ultrasonographic patterns.

CONCLUSIONS

Among the current radiological imaging techniques, ultrasound has the highest axial spatial resolution. Compared to other imaging techniques used in dermatology, it shows the great advantage of penetrating the soft tissues thoroughly, which allows us to detect and identify the most common skin types of skin cancer, including both the primary tumor and its locoregional metastases.

The Usefulness of Ultrasonography for Supporting the Differentiation, Diagnosis, and Treatment of Atypical Fibroxanthoma and Pleomorphic Dermal Sarcoma

Atypical fibroxanthoma (AFX) and pleomorphic dermal sarcoma (PDS) are rare histomorphological variants of a disease spectrum. After ruling out other tumor entities by immunohistochemistry, PDS can be differentiated from AFX by infiltration into the subcutis, while AFX remains confined to the dermis. The therapeutic approach is more aggressive in PDS as it can potentially metastasize. We assessed the usefulness of preoperative sonography in differentiating between the two tumor entities by identifying a potential subcutaneous infiltration. In our patients (n = 13), preoperative sonography identified and differentiated AFX and PDS with 100% accuracy and even changed the initial histological suspicion of AFX to PDS in 3 cases (23%), which was confirmed after tumor resection. Preoperative sonography of these tumors could strengthen the clinical diagnosis, avoid a delay in therapy initiation and improve patient counseling. While for AFX, micrographic-controlled surgery suffices, for PDS, resection with 2 cm safety margins and lymph node sonography to rule out lymphonodal involvement is necessary. Hence, ultrasonography can improve clinical practice by providing helpful information for dermatosurgeons, which cannot be obtained during clinical examination.

Rationale for Using High-Frequency Ultrasound as a Routine Examination in Skin Cancer Surgery: A Practical Approach

Ultrasound and high-frequency ultrasound assessment of melanoma and non-melanoma skin cancer in the pre-therapeutical setting is becoming increasingly popular in the field of dermatosurgery and dermatooncology, as it can provide clinicians with relevant, "in vivo" parameters regarding tumor lateral and depth extension as well as potential locoregional spread, cancelling the need of more extensive imaging methods and avoiding a delay in diagnosis. Furthermore, preoperative sonography and color Doppler can aid in orienting the clinical diagnosis, being able in numerous situations to differentiate between benign and malignant lesions, which require a different therapeutic approach. This preoperative knowledge is of paramount importance for planning an individualized treatment regimen. Using sonography at the time of diagnosis, important surgical complications, such as neurovascular damage, can be avoided by performing a preoperative neurovascular mapping. Furthermore, sonography can help reduce the number of surgical steps by identifying the lesions' extent prior to surgery, but it can also spare unnecessary surgical interventions in cases of locally advanced lesions, which infiltrate the bone or already present with locoregional metastases, which usually require modern radiooncological therapies in accordance to European guidelines. With this review, we intend to summarize the current indications of sonography in the field of skin cancer surgery, which can help us improve the therapeutic attitude toward our patients and enhance patient counseling. In the era of modern systemic radiooncological therapies, sonography can help better select patients who qualify for surgical procedures or require systemic treatments due to tumoral extension.

Ultrasound Features of Nail Lichen Planus

OBJECTIVES

To describe the ultrasonographic features of nail lichen planus (NLP), which, so far, have not been reported in the literature.

METHODS

A retrospective single-center study of NLP patients' color Doppler ultrasound examinations was performed between March 2014 and January 2023. Inclusion criteria were patients ≥15 years with a confirmed clinical diagnosis of NLP in sequential order. Exclusion criteria included concomitant systemic or local cutaneous or nail diseases and systemic or local nail treatments before the ultrasound examination. The ultrasound protocol included the examination of all fingernails or toenails following the reported protocol for dermatologic ultrasound examinations at high and ultra-high frequencies. Patient demographics and ultrasound features of the nail bed, periungual region, nail plate, and regional vascularity were registered and analyzed statistically.

RESULTS

A total of 36 patients met the criteria. All cases presented thickened and decreased echogenicity of the nail bed. A hypoechoic halo surrounding the origin of the nail plate was present in 78% of cases. Exactly 58% of patients presented decreased echogenicity of the proximal periungual dermis, and 86% showed thickening of the periungual dermis. Hypervascularity of the nail bed was seen in 94% of cases. The mean maximum thickness of vessels, the peak systolic velocity of the arterial vessels, and other blood flow findings are provided.

CONCLUSION

Ultrasonography can support the diagnosis of NLP, which benefits the non-invasive discrimination of nail conditions and can avoid the potential permanent scars derived from nail biopsies. Furthermore, ultrasound may be a powerful tool to monitor this disease's treatment.