Screening for interstitial lung disease in systemic sclerosis: performance of high-resolution CT with limited number of slices: a prospective study

Recent Treatments of Interstitial Lung Disease with Systemic Sclerosis

Systemic sclerosis (SSc) is a disorder characterized by immune dysfunction, microvascular injury, and fibrosis. Organ involvement in patients with SSc is variable; however, pulmonary involvement occurs in up to 90% of patients with SSc. Interstitial lung disease (ILD) is a major cause of mortality and, thus, a major determinant in the prognosis of patients with SSc. This review summarizes current findings about the characteristics of ILD in patients with SSc, selection of patients with SSc-ILD who are candidates for the treatment, and current treatment options.

Evaluation of pulmonary nodules and infection on chest CT with radiation dose equivalent to chest radiography: Prospective intra-individual comparison study to standard dose CT

PURPOSE

To compare prospectively, in patients undergoing chest computed tomography (CT) for pulmonary-nodules or infection, image-quality and accuracy of standard dose (SD) and reduced dose (RD) CT with tin-filtration.

MATERIAL AND METHODS

This IRB-approved study included 100 consecutive patients (36 female;median age 56 years) referred for follow-up of pulmonary-nodules (n=43) or suspicion of infection (n=57) undergoing single-energy CT with SD and RD using tin-filtration at 100 kVp (CTDIvol 2.47 mGy and 0.07 mGy, respectively). Images were reconstructed with advanced modeled iterative reconstruction (ADMIRE) at strength 3 and 5. Image-noise was measured. Two independent readers evaluated nodules and pulmonary-infection. SD CT served as reference standard.

RESULTS

No significant difference was found in noise between RD with ADMIRE5 and SD with ADMIRE3 (118HU ± 14 vs. 120HU ± 17; p=0.08). Sensitivity for detection of atelectasis and interstitial lung changes was higher in images reconstructed with ADMIRE5 (93% and 88%; respectively) than in those reconstructed with ADIMRE3 (77% and 78%; respectively). Sensitivity for detection of consolidations was 90% for ADMIRE3 and 89% for ADMIRE5. Sensitivity for nodule detection was 71% for ADMIRE3 and 81% for ADMIRE5. Specificity for detection of atelectasis and interstitial lung changes was 99% and 96% with ADMIRE5 and 99% and 96% with ADMIRE3. Specificity for detection of consolidations was 99% for ADMIRE3 and 5. Specificity for detection of nodules was 87% for both ADMIRE3 and 5.

CONCLUSION

Chest CT with a radiation dose equivalent to conventional radiography is feasible and allows for detection of pulmonary infection with high sensitivity, whereas the accuracy for detecting nodules is only moderate.

Ultrasound signs of pulmonary fibrosis in systemic sclerosis as timely indicators for chest computed tomography

OBJECTIVES

Systemic sclerosis (SSc) patients in the early stages of pulmonary fibrosis (PF) often have few or no symptoms, normal to borderline pulmonary function tests, and negative chest X-ray (CXR); high-resolution computed tomography (HRCT) is the only reliable means of detecting the early signs of PF. However, thoracic ultrasound (TUS) enables detection of pleural thickening, pleural/subpleural nodules, and other subpleural lung abnormalities across 70% of the subpleural surface. We reassessed concordance between TUS abnormalities and HRCT findings in SSc patients, to see whether TUS pleural line thickness (normally <3.0 mm) could be used to earmark those with asymptomatic PF for timely HRCT assessment.

METHOD

In total, 175 SSc patients (nine males, 166 females), aged 46.46±15.33 years, were given CXR, TUS, HRCT, echocardiography, and pulmonary function tests.

RESULTS

In the 26 patients without HRCT signs of PF, pleural line thickness was ≤3.0 mm. In diffuse SSc, 97/137 patients showed pleural line thickening (between 3.0 and 5 mm) and subpleural nodules in 32/97; and 35/137 showed major pleural line thickening (≥5.0 mm) with nodules, with good concordance with HRCT patterns indicating lung fibrosis severity. HRCT was normal in 5/137, with pleural line thickness≤3.0 mm.

CONCLUSIONS

TUS imaging of pleural/subpleural structures can detect ultrasonographic signs of initial PF prior to the onset of respiratory symptoms and function test abnormalities and, together with current criteria, could thereby enable exclusion of PF in SSc patients. Indicating some patients for selective referral to HRCT can thereby delay unwarranted procedures, provided that pulmonary function and TUS images are stable.

Systemic sclerosis

Systemic sclerosis is a complex autoimmune disease characterized by a chronic and frequently progressive course and by extensive patient-to-patient variability. Like other autoimmune diseases, systemic sclerosis occurs more frequently in women, with a peak of onset in the fifth decade of life. The exact cause of systemic sclerosis remains elusive but is likely to involve environmental factors in a genetically primed individual. Pathogenesis is dominated by vascular changes; evidence of autoimmunity with distinct autoantibodies and activation of both innate and adaptive immunity; and fibrosis of the skin and visceral organs that results in irreversible scarring and organ failure. Intractable progression of vascular and fibrotic organ damage accounts for the chronic morbidity and high mortality. Early and accurate diagnosis and classification might improve patient outcomes. Screening strategies facilitate timely recognition of life-threatening complications and initiation of targeted therapies to halt their progression. Effective treatments of organ-based complications are now within reach. Discovery of biomarkers - including autoantibodies that identify patient subsets at high risk for particular disease complications or rapid progression - is a research priority. Understanding the key pathogenetic pathways, cell types and mediators underlying disease manifestations opens the door for the development of targeted therapies with true disease-modifying potential. For an illustrated summary of this Primer, visit: http://go.nature.com/lchkcA.