Shear-wave elastography (SWE) imaging can be used to distinguish localized scleroderma (LS) lesions from normal skin in pediatric patients, according to study results published in Ultrasound in Medicine and Biology.
Although several objective clinical scoring methods have been previously proposed, the specificity of these methods has not been validated in larger cohorts. The current study sought to assess the feasibility and reliability of elastography ultrasound for the identification of lesions in children with LS.
Children who received care at the Morphea Clinic at The Hospital for Sick Children in Toronto, Canada, from March 2017 to July 2018, were eligible for inclusion in the study. Participants with at least 1 LS plaque with an area less than 100 cm2 were enrolled. Researchers selected a target study lesion, which was evaluated by existing metrics, including the Physician Global Assessment of Disease Damage (PGA-D) and the Physician Global Assessment of Disease Activity (PGA-A). Demographic data and clinical history were extracted from medical records.
Patients then underwent an ultrasound examination by grayscale B-mode, color Doppler, and SWE imaging. Scans were performed by an experienced sonographer who was blinded to the results of the initial clinical examination. Skin thickness and elasticity were calculated for each layer within the region of interest. Spearman’s correlation test was used to examine the relationship between elastography ultrasound measures and clinical examination outcomes.
The study cohort included 13 participants (median age, 10 years; mean disease duration, 3.1±1.2 years), among whom 10 were girls. A total of 7 of 13 lesions (53.8%) had at least some degree of activity (PGA-A>0), with a mean PGA-A value of 35.7 in the active lesions.
The SWE scans showed that skin thickness and elasticity differed significantly between the lesion and control regions. These differences persisted across the dermis and hypodermis (P <.05). The SWE velocity in the LS regions was significantly higher than that in the control regions (2.25 vs 1.90 m/s, respectively, in the dermis [P =.021]; 2.08 vs 1.71 m/s, respectively, in the hypodermis [P =.026]). The elastic modulus value means were also significantly higher for lesion vs control regions (15.71 vs 10.35 kPa, respectively, in the dermis [P =.026]; 14.56 vs 9.76 kPa, respectively, in the hypodermis [P =.032]). In addition, the LS vs control regions had greater mean intralesion variability in elasticity (47% vs 12%, respectively). In grayscale B-mode ultrasound and color Doppler, the combined dermis/hypodermis skin thickness in lesions was 30.7% less than that of the healthy skin. An increase in echogenicity in lesions compared to control sites was observed in 7 patients.
These data support the use of elastography ultrasound to distinguish LS lesions from healthy skin in pediatric populations. In particular, SWE ultrasound was able to assess tissue deformation and elasticity, from which inferences about skin stiffness could be made.
Researchers noted study limitations including the small sample size and the relatively narrow spectrum of disease activity, with mostly inactive lesions. Further studies in a larger cohort with more diverse lesion presentation is necessary to validate these findings.
“Our preliminary results indicate that SWE is a feasible method of quantitatively discriminating between lesions and non-affected skin in individuals with pediatric-onset LS, which shows great promise in aiding the clinical assessment of disease activity,” the researchers concluded.
Pérez M, Zuccaro J, Mohanta A, Tijerin M, Laxer R, Pope E, Doria AS. Feasibility of using elastography ultrasound in pediatric localized scleroderma (morphea). Ultrasound Med Biol. Published online September 17, 2020. doi:10.1016/j.ultrasmedbio.2020.08.007