Lung Ultrasound for Assessment of Interstitial Lung Disease in Systemic Sclerosis: Relationship With High-Resolution Computed Tomography and Nailfold Capillaroscopy.

Abstract

Background: Lung ultrasound (LUS) has been recently proposed as a convenient and radiation-free imaging modality for the evaluation of systemic sclerosis-related interstitial lung disease.

Objectives: The current study evaluates the relation between LUS and both high-resolution computed tomography (HRCT) and capillaroscopy findings in patients with systemic sclerosis.

Design: This cross-sectional study included 32 patients with systemic sclerosis.

Methods: Besides clinical evaluation, all participants underwent LUS, HRCT, pulmonary function tests (PFT), and nailfold video-capillaroscopy (NVC). All participants' data were compared and correlated.

Results: There is an excellent agreement between number of B-lines and HRCT score (interclass correlation = 0.864, P-value < .001). A significant positive correlation exists between number of B-lines and disease duration (r = 0.459, P-value = .008). Conversely, the number of B-lines is negatively correlated with capillary density (r = -0.687, P-value < .001), forced expiratory volume in the first second (FEV1) (r = -0.886, P-value < .001), and forced vital capacity (FVC) (r = -0.898, P-value < .001). Patients with either neoangiogenesis or previous/current digital ulcers had significantly higher number of B-lines than those without (P-value < .001, .016, respectively).

Conclusion: The number of B-lines parallels the HRCT score and the extent of digital vascular damage as indicated by NVC and clinical digital ulcers. Lung ultrasound has proven to be a reliable radiation-free modality for screening of systemic sclerosis-related interstitial lung disease and detecting its extent.