Table 3.

Pros and cons of interstitial lung disease screening modalities in systemic sclerosis

	Modality	Pros	Cons
Current approach to screening	HRCT at baseline	High-resolution Standardized protocol for study performance and interpretation Characterize and differentiate lung disease morphology	Radiation exposure
	Pulmonary function test	Useful information on lung function Inexpensive	Not a screening test Has to be used in conjunction with HRCT
	Autoantibody testing	Prognostication with anti-SCL70 positivity	Not a screening test Has to be used in conjunction with HRCT
Newer innovations	Low-dose CT scan	Comparable sensitivity and specificity Low radiation exposure	Potential near miss
	Computer-aided CT scans	Consistency in reporting for common findings – nodules, GGOs, fibrosis Standardization in quantification	Not widely available Comparability between software not known
	PET-CT scans	Metabolic activity as indicated by FDG uptake could differentiate areas of inflammation from fibrosis Gallium labelled protocols may indicate extent of fibrosis more accurately	Large scale studies needed to understand the role in screening
	Lung ultrasound	Relatively inexpensive compared to CT No radiation exposure Comparable to CT as a screening tool although criteria need to be defined	Operator dependent Potential confounders from other lung pathologies (e.g. pulmonary edema etc.)
	Lung MRI	No radiation exposure Certain sequences may differentiate between areas of active inflammation and fibrosis	Expensive Cannot differentiate between patterns of ILD
	Novel biomarkers*	Quick, less invasive, and potentially less expensive Convenient	Variable sensitivity and low specificity Large scale studies needed to understand the role in screening
	E-nose	Convenient and quick Can distinguish patients with ILD from healthy controls	Large scale studies needed to understand the role in screening

^*KL-6, SP-D, and biomarkers of lung epithelial cell dysfunction, aberrant immunity, and abnormal lung remodeling