RT Journal Article
SR Electronic
T1 High-frequency Ultrasound Assessment of Systemic Sclerosis Skin Involvement: Intraobserver Repeatability and Relationship With Clinician Assessment and Dermal Collagen Content
JF The Journal of Rheumatology
JO J Rheumatol
FD The Journal of Rheumatology
SP jrheum.200234
DO 10.3899/jrheum.200234
A1 Victoria A.  Flower
A1 Shaney L.  Barratt
A1 Darren J.  Hart
A1 Amanda B.  Mackenzie
A1 Jacqueline A.  Shipley
A1 Stephen G.  Ward
A1 John D.  Pauling
YR 2020
UL http://www.jrheum.org/content/early/2021/03/10/jrheum.200234.abstract
AB Objective The modified Rodnan skin score (mRSS) remains the preferred method for skin assessment in systemic sclerosis (SSc). There are concerns regarding high interobserver variability of mRSS and negative clinical trials utilizing mRSS as the primary endpoint. High-frequency ultrasound (HFUS) allows objective assessment of cutaneous fibrosis in SSc. We investigated the relationship between HFUS with both mRSS and dermal collagen. Methods Skin thickness (ST), echogenicity, and novel shear wave elastography (SWE) were assessed in 53 patients with SSc and 15 healthy controls (HCs) at the finger, hand, forearm, and abdomen. The relationship between HFUS parameters with mRSS (n = 53) and dermal collagen (10 patients with SSc and 10 HCs) was investigated. Intraobserver repeatability of HFUS was calculated using intraclass correlation coefficients (ICCs). Results HFUS assessment of ST (hand/forearm) and SWE (finger/hand) correlated with local mRSS at some sites. Subclinical abnormalities in ST, echogenicity, and SWE were present in clinically uninvolved SSc skin. Additionally, changes in echogenicity and SWE were sometimes apparent despite objectively normal ST on HFUS. ST, SWE, and local mRSS correlated strongly with collagen quantification (r = 0.697, 0.709, 0.649, respectively). Intraobserver repeatability was high for all HFUS parameters (ICCs for ST = 0.946– 0.978; echogenicity = 0.648–0.865; and SWE = 0.953–0.973). Conclusion Our data demonstrate excellent reproducibility and reassuring convergent validity with dermal collagen content. Detection of subclinical abnormalities is an additional benefit of HFUS. The observed correlations with collagen quantification support further investigation of HFUS as an alternative to mRSS in clinical trial settings.