High-Frequency Ultrasound Investigation of Port-Wine Stains: Hemodynamic Features Revealed By 10- and 22-MHz Transducers

Non-invasive efficacy assessment of pulsed dye laser and photodynamic therapy for port-wine stain

Port wine stain (PWS) is a congenital vascular malformation that commonly occurs on the face and neck. Currently, the main treatments for port wine stain are pulsed dye laser (PDL) and photodynamic therapy (PDT). However, the efficacy evaluation of PWS mostly relies on the subjective judgement of clinicians, and it is difficult to accurately respond to many small changes after treatment. Therefore, some non-invasive and efficient efficacy assessment methods are also needed. With the continuous development of technology, there are currently many visualisation instruments to evaluate PWS, including dermoscopy, VISIA-CR™ system, reflectance confocal microscopy (RCM), high-frequency ultrasound (HFUS), optical coherence tomography (OCT), Photoacoustic imaging (PAI), laser speckle imaging (LSI) and laser Doppler imaging (LDI). Among them, there are simple and low-cost technologies such as dermoscopy and the VISIA-CR™ system, but they may not be able to observe the deeper structures of PWS. At this time, combining techniques such as HFUS and OCT to increase penetration depth is crucial to evaluate PWS. In the future, the combination of these different technologies could help overcome the limitations of a single technology. This article provides a systematic overview of non-invasive methods for evaluating treatment efficacy in port wine stains and summarises their advantages and disadvantages.

High speed photo-mediated ultrasound therapy integrated with OCTA

Photo-mediated Ultrasound Therapy (PUT), as a new anti-vascular technique, can promote cavitation activity to selectively destruct blood vessels with a significantly lower amount of energy when compared to energy level required by other laser and ultrasound treatment therapies individually. Here, we report the development of a high speed PUT system based on a 50-kHz pulsed laser to achieve faster treatment, decreasing the treatment time by a factor of 20. Furthermore, we integrated it with optical coherence tomography angiography (OCTA) for real time monitoring. The feasibility of the proposed OCTA-guided PUT was validated through in vivo rabbit experiments. The addition of OCTA to PUT allows for quantitative prescreening and real time monitoring of treatment response, thereby enabling implementation of individualized treatment strategies.

Analysis of port-wine birthmark vascular characteristics by location: Utility of optical coherence tomography mapping

INTRODUCTION

Port-wine birthmarks (PWBs) are congenital capillary malformations that can be located on any area of the body. Vascular features include vessel size, depth, and density, which can greatly differ between patients, individual lesions, and even sites within the same lesion. Previous studies have determined that the location of PWB lesions has impacted their clinical response to laser treatment.

OBJECTIVE

We utilized dynamic optical coherence tomography (D-OCT) to measure in vivo vessel diameter, density, and superficial plexus depth in patients of all ages with PWB on various sites of the body. We hypothesized that these vascular characteristics would differ according to body location.

MATERIALS AND METHODS

Patients who had a PWB and presented to clinic at three sites for treatment with the pulsed dye laser (PDL) were enrolled into the study. A D-OCT scanner was utilized for noninvasive, in vivo imaging of PWB lesions. The depth of the top portion of the superficial vascular plexus was estimated as the depth at which the vessel density reaches 50% of the maximum. Vessel diameter and density were calculated by incorporated software algorithm.

RESULTS

A total of 108 patients were enrolled into the study. There was a total of 204 measurements of PWB lesions. Of all patients, 56.5% (n = 61) reported having a previous treatment with PDL. Of all D-OCT scans, 62.3% (n = 127) were located on the head, 14.2% (n = 29) the upper extremities, 8.3% (n = 17) the lower extremities, 7.8% (n = 16) the trunk, and 7.8% (n = 15) the neck. All locations were compared for each vascular characteristic. For superficial plexus depth, lesions on the head were significantly shallower than those on the upper extremities (217 vs. 284 µm; p < 0.001) and lower extremities (217 vs. 309 µm; p < 0.001). For vessel diameter, lesions on the head had significantly larger vessels than those on the upper extremities (100 vs. 72 µm; p = 0.001). For vessel density, lesions on the head had significantly denser vessels than those on the trunk (19% vs. 9.6%; p = 0.039) and upper extremities (19% vs. 9.3%; p < 0.001) CONCLUSIONS: PWB lesions have distinct vascular characteristics, which can be associated with their body location. This includes superficial vascular plexus depth as well as vessel diameter and density.

High-frequency ultrasound in clinical dermatology: a review

Background

Ultrasound was first introduced in clinical dermatology in 1979. Since that time, ultrasound technology has continued to develop along with its popularity and utility.

Main text summary

Today, high-frequency ultrasound (HFUS), or ultrasound using a frequency of at least 10 megahertz (MHz), allows for high-resolution imaging of the skin from the stratum corneum to the deep fascia. This non-invasive and easy-to-interpret tool allows physicians to assess skin findings in real-time, enabling enhanced diagnostic, management, and surgical capabilities. In this review, we discuss how HFUS fits into the landscape of skin imaging. We provide a brief history of its introduction to dermatology, explain key principles of ultrasonography, and review its use in characterizing normal skin, common neoplasms of the skin, dermatologic diseases and cosmetic dermatology.

Conclusion

As frequency advancements in ultrasonography continue, the broad applications of this imaging modality will continue to grow. HFUS is a fast, safe and readily available tool that can aid in diagnosing, monitoring and treating dermatologic conditions by providing more objective assessment measures.

Noninvasive diagnostic techniques of port wine stain

Port-wine stain (PWS) is a benign capillary malformation that most commonly occurs in the head and neck. It is present at birth and progresses over time. It is formed by progressive dilatation of post-capillary venules and is associated with hypertrophy and nodularity with increasing age, leading to cosmetic disfigurement and psychological aggravation. It is caused by genetic mosaicism in GNAQ and GNA11 genes. Histopathology is the gold standard for assessment of PWS but it is invasive and may cause scarring. Inadequate characterization of the lesions may predispose to inadequate treatment protocols as well as higher treatment dosages. Clinical evaluation of treatment efficacy is subjective and may not be a representative of actual results. Therefore, an objective visualization modality is required. With evolving technology, numerous optical instruments have been developed for objective evaluation and visualization of subsurface structures. These include VISIA-CR™ system, videodermoscopy, high-frequency ultrasound (HFUS), laser speckle contrast imaging (LSCI), reflectance spectrophotometers and tristimulus colorimeter, laser Doppler flowmetry (LDF), cross-polarized diffuse reflectance imaging system (CDR), reflectance confocal microscopy (RCM), optical coherence tomography (OCT), and spatial frequency domain imaging (SFDI). These semi-quantitative modes of diagnosis are complementary to each other. Some can be used in the clinical setting while others, due to high instrument cost, are limited to the research settings. In this review, we bring to you a brief overview of noninvasive diagnostic modalities in PWS.

Role of colour-Doppler high-frequency ultrasonography in capillary malformation-arteriovenous malformation syndrome: a case series

High-frequency ultrasonography (HFUS) represents a useful adjunct for dermatologists in the diagnosis of capillary malformation-arteriovenous malformation (CM-AVM) syndrome. We present a paediatric case series of 6 patients with confirmed RASA1 gene mutation in whom HFUS demonstrated AVM beneath cutaneous CM-like lesions greater than 1.5 cm.

Cutaneous ultrasound and its utility in Pediatric Dermatology: Part II-Developmental anomalies and vascular lesions

High-frequency ultrasonography represents a promising tool for pediatric dermatologists. It is a noninvasive and harmless diagnostic technique that is especially appealing when working with children. It can be easily performed at the patient's bedside, avoiding diagnostic delays, sedation, or multiple visits. It represents a useful adjunct to clinical examination and aids our understanding of cutaneous pathology. In this second part, we describe the ultrasonographic findings of developmental anomalies and vascular lesions.

Quantification of skin lesions using high-frequency ultrasound and shear wave elastography in port-wine stain patients: a clinical study

Background

This study aimed to assess the different types of port-wine stain (PWS) skin lesions quantitatively using high-frequency ultrasound (US) and shear wave elastography (SWE) before and after treatment, and investigate the feasibility and application value of high-frequency US and SWE in PWSs.

Methods

A total of 195 PWS patients with 238 skin lesions before treatment and 72 follow-up PWS patients with 90 skin lesions were assessed using high-frequency US and SWE. The skin lesions were divided into four groups: pink-type, purple-type, thickened-type, and nodular-type PWSs. Gray-scale US was used to observe normal skin, observe the skin changes of lesions, and assess the skin thickness. The thickened skin was calculated. Power Doppler (PD) signal grades were used to assess the skin blood signals. SW velocity (in m/s) and Young's elastic modulus (in kPa) were used to assess the stiffness of normal skin and skin lesions. The heightened SWE was also calculated.

Results

The dermis hypoechogenicity, thickness of thickened skin, and skin PD signal grades were significantly higher in all PWS-type groups compared with the normal-skin group (all P<0.05). The thickened skin and skin PD signal grades in the nodular-type and thickened-type group were significantly thicker and higher than those in the pink-type and purple-type group (all P<0.05). The PD signal grades in the purple-type was significantly higher than that in the pink-type group (P<0.05). All SWE values of PWS lesions were significantly higher in the transverse section than those in the longitudinal section (all P<0.05). The differences in heightened E_mean, E_min, C_mean, and C_min between each PWS group and the normal-skin group were not significant. The heightened E_max and C_max in the nodular-type PWS group was significantly higher than those in the normal-skin group and pink-type, and purple-type PWS groups (all P<0.05). The heightened E_max and C_max were significantly higher in the thickened-type PWS group than those in the normal-skin group (all P<0.05). In the evaluation of therapeutic effects, the ratio of dermis hypoechogenicity in pink-type lesions significantly decreased, and thickened skins in all groups were significantly thinned (all P<0.05). The differences of PD signal grades, heightened E_max, and C_max in all groups between pre-treatment and post-treatment showed no significance.

Conclusions

High-frequency US and SWE show feasibility and application values assessing PWS skin lesions. Their features include dermis hypoechogenicity, thicker skin, higher PD signal grades, higher E_max, and higher C_max. Thicker skin is thus the best feature for assessing therapeutic effect.