Computed Tomographic Imaging in Connective Tissue Diseases

Joseph Barnett, FRCR; Anand Devaraj, MD, MRCP, FRCR


Semin Respir Crit Care Med. 2019;40(2):159-172. 

In This Article

Acute Exacerbations

Acute exacerbation describes an acute (<1 month) deterioration of respiratory function accompanied by diffuse ground-glass infiltrate on HRCT, in the absence of another known cause (e.g., pulmonary edema or infection).[128] This process is characterized histopathologically by DAD. Such acute exacerbations can be idiopathic, or triggered by pulmonary injury such as infection, intervention, or secondary to pharmacological therapy. While such reactions are defined in the context of IPF;[128] acute exacerbation of collagen vascular ILD has been described in all forms of CTD-ILD.[129–131]

The HRCT features are nonspecific, comprising a nonfibrotic ground-glass infiltrate, and in the majority of cases, this is associated with consolidation.[130] The distribution of abnormalities may be peripheral, multifocal, or diffuse.[43]

Of the various CTDs associated with ILD, acute exacerbation appears to most frequently occur in RA-ILD,[130] the incidence appearing to approach the incidence of acute exacerbation in IPF.[43] Acute exacerbations associated with CTD-ILDs carry a high risk of mortality.[129]