High-Resolution Computed Tomographic Findings in Systemic Sclerosis–Associated Interstitial Lung Disease: Comparison Between Diffuse and Limited Systemic Sclerosis

Diagnosis and monitoring of systemic sclerosis-associated interstitial lung disease using high-resolution computed tomography

Patients with systemic sclerosis are at high risk of developing systemic sclerosis-associated interstitial lung disease. Symptoms and outcomes of systemic sclerosis-associated interstitial lung disease range from subclinical lung involvement to respiratory failure and death. Early and accurate diagnosis of systemic sclerosis-associated interstitial lung disease is therefore important to enable appropriate intervention. The most sensitive and specific way to diagnose systemic sclerosis-associated interstitial lung disease is by high-resolution computed tomography, and experts recommend that high-resolution computed tomography should be performed in all patients with systemic sclerosis at the time of initial diagnosis. In addition to being an important screening and diagnostic tool, high-resolution computed tomography can be used to evaluate disease extent in systemic sclerosis-associated interstitial lung disease and may be helpful in assessing prognosis in some patients. Currently, there is no consensus with regards to frequency and scanning intervals in patients at risk of interstitial lung disease development and/or progression. However, expert guidance does suggest that frequency of screening using high-resolution computed tomography should be guided by risk of developing interstitial lung disease. Most experienced clinicians would not repeat high-resolution computed tomography more than once a year or every other year for the first few years unless symptoms arose. Several computed tomography techniques have been developed in recent years that are suitable for regular monitoring, including low-radiation protocols, which, together with other technologies, such as lung ultrasound and magnetic resonance imaging, may further assist in the evaluation and monitoring of patients with systemic sclerosis-associated interstitial lung disease. A video abstract to accompany this article is available at: https://www.globalmedcomms.com/respiratory/Khanna/HRCTinSScILD.

Worsening of esophageal dilatation is associated with increase in a high-resolution computed tomography (HRCT) score in early systemic sclerosis-associated interstitial lung disease (SSc-ILD)

BACKGROUND

Data regarding longitudinal association between changes (Δ: time2-time1) in the widest esophageal diameter (WED) and Δ HRCT score in early SSc-ILD patients is limited. We therefore investigated the association of ΔWED with Δ HRCT score and predictors of a worse Δ HRCT score in those patients.

METHODS

We used an inception cohort of early SSc-ILD patients with availability for two HRCT records at enrollment and 1-year follow-up.The extent of ground glass, reticulation, bronchiectasis, and honeycombing was scored and then aggregated to produce a total HRCT score. The WED was measured at four levels and the maximum value was used. The Δ maximum WED, Δ mean WED, and Δ tHRCT score were analyzed.

RESULTS

We recruited 75 early SSc-ILD patients and found a significant correlation of Δ tHRCT score with a Δ maximum WED (rho = 0.34, p < 0.01) and Δ mean WED (rho = 0.26, p < 0.05). There were 34 patients with a worsening Δ tHRCT (Δ > 0), 17 with stability (Δ = 0), and 24 with improvement (Δ < 0). Patients with a worsening ILD had a significantly shorter disease duration, lower prevalence of tendon friction rub, higher cumulative prednisolone dose, and larger ΔWED than those with stable and improved Δ tHRCT scores. Multivariate ordinal logistic regression identified a larger Δ mean WED (OR 1.21, 95% CI 1.03-1.42, p = 0.02) as a predictor of worsening HRCT score, while presence of tendon friction rub was associated with a lower risk (OR 0.18, 95% CI 0.04-0.77, p = 0.021).

CONCLUSION

Our study cohort found that a worsening esophageal diameter was a predictor of progression of lung fibrosis determined by HRCT score in early SSc-ILD. A further study regarding esophageal dilation progression different in early versus longstanding SSc-ILD is needed. Key Points •In early SSc-ILD patients, we demonstrated that a worsening esophageal diameter was a predictor of progression of HRCT score at 1-year follow-up. •Further study regarding the association of worsening of the esophageal dilatation with the progression of ILD comparing between early versus late SSc-ILD is needed.

Computed tomography assessment of evolution of interstitial lung disease in systemic sclerosis: Comparison of two scoring systems

BACKGROUND

The aim of this study was to evaluate and compare the internal and external responsiveness of a computed-aided method (CaM) with a conventional visual reader-based score (CoVR) to measure interstitial lung disease (ILD) in patients with systemic sclerosis (SSc) on high resolution computed tomography (HRCT).

METHODS

Forty-five patients were evaluated in this retrospective cohort. HRCTs were collected at baseline and after 1 year. HRCT abnormalities were evaluated according to a CoVR (Warrick's method) and a quantitative CaM. Internal 1-year responsiveness was tested with a standardized mean response (SRM). Analyses of the receiver operating characteristic curves (ROCs) evaluated the sensitivity and specificity of the two methods to discriminate between clinically relevant progression and no relevant progression, using expert judgment as the gold standard (external responsiveness).

RESULTS

In one year, lung involvement was stable/improved in 17 of the 45 patients (37.8%) and worsened in 28 patients (62.2%). HRCT scores changed moderately over the follow-up period. Using SFM, CaM was significantly more responsive in detecting changes due to treatment than the CoVR method. Likewise, in the analysis of the ROC curve, CaM scores showed the highest performance (AUC ROC CaM vs. CoVR, 0.951 vs. 0.807; p = 0.0065).

CONCLUSION

Quantitative analysis of CaM was more responsive than the CoVR method to accurately evaluate and monitor SSc-ILD progression or response to therapy.

GI Manifestations With a Focus on the Esophagus: Recent Progress in Understanding Pathogenesis

PURPOSE OF REVIEW

Esophageal dysfunction is common in systemic sclerosis (SSc) patients. Limited treatment options are available for scleroderma esophageal disease. Here, we discuss recent updates on the diagnosis, treatment, and characterization that have been made in patients with scleroderma esophageal disease.

RECENT FINDINGS

In the past few years, novel diagnostic tools have provided insight into esophageal dysmotility in SSc patients. New drugs are being tested and might improve symptoms and quality of life in SSc patients with esophageal dysfunction. Molecular stratification methods have facilitated the identification of molecular signatures in the esophagus of SSc patients. The Friend leukemia integration 1 (Fli1) conditional knockout mouse is the first animal model to report an esophageal phenotype with SSc features. The clinical presentation in SSc patients with esophageal dysfunction is heterogeneous, complicating diagnosis and management. The improvement of diagnostic tools for esophageal symptoms and dysfunction and the use of molecular approaches in SSc mouse models and patient biopsies offer an opportunity to improve the characterization of SSc esophageal disease, which should help improve management and treatment decisions.

Performance of a new quantitative computed tomography index for interstitial lung disease assessment in systemic sclerosis

Quantitative high resolution computed tomography (HRCT) may objectively assess systemic sclerosis (SSc)-interstitial lung disease (ILD) extent, using three basic densitometric measures: mean lung attenuation (MLA), skewness, and kurtosis. This prospective study aimed to develop a composite index - computerized integrated index (CII) – that accounted for MLA, skewness, and kurtosis by means of Principal Component Analysis over HRCTs of 83 consecutive SSc subjects, thus eliminating redundancies. Correlations among CII, cardiopulmonary function and immune-inflammatory biomarkers (e.g. sIL-2Rα and CCL18 serum levels) were explored. ILD was detected in 47% of patients at visual HRCT assessment. These patients had worse CII values than patients without ILD. The CII correlated with lung function at both baseline and follow-up, and with sIL-2Rα and CCL18 serum levels. The best discriminating CII value for ILD was 0.1966 (AUC = 0.77; sensitivity = 0.81 [95%CI:0.68–0.92]; specificity = 0.66 [95%CI:0.52–0.80]). Thirty-four percent of patients without visual trace of ILD had a CII lower than 0.1966, and 67% of them had a diffusing lung capacity for CO <80% of predicted. We showed that this new composite CT index for SSc-ILD assessment correlates with both lung function and immune-inflammatory parameters and could be sufficiently sensitive for capturing early lung density changes in visually ILD-free patients.

Relationship between interstitial lung disease and oesophageal dilatation on chest high-resolution computed tomography in patients with systemic sclerosis: a cross-sectional study

OBJECTIVES

Oesophageal dilatation (OD) has been implicated in the pathogenesis of interstitial lung disease (ILD) in systemic sclerosis (SSc). The aims of this study were to explore the association of the OD and SSc-ILD on chest high-resolution computed tomography (HRCT), and to establish a cutoff point for the OD suggestive for the presence of a significant lung involvement.

METHODS

The widest oesophageal diameter (WOD) was obtained on axial HRCT images. The parenchymal abnormalities on HRCT were coded and scored according to Warrick method. Patient-centred measures, pulmonary function tests and the single breath carbon monoxide diffusing capacity of the lung (DLco) were also obtained. Multivariate regression analysis was performed to identify factors associated with oesophageal diameter.

RESULTS

126 subjects with SSc were included. The mean (± SD) WOD was 13.5 (± 4.2) mm, and in 76 (60.3%) participants WOD was ≥ 11 mm. SSc patients with ILD had larger oesophageal diameters than those without lung disease (19.4 vs. 14.1 mm, p < 0.001). We observed a high correlation between WOD and gastro-oesophageal reflux disease questionnaire (GerdQ) (r = 0.886, p < 0.001), Borg score (r = 0.705, p < 0.001), and Warrick score (r = 0.614, p < 0.001). WOD negatively correlated with DLco (r = - 0.508, p < 0.001). Multivariate analysis demonstrated positive associations between WOD and GerdQ (p < 0.0001), Borg score (p < 0.0005), and total Warrick score (p = 0.019).

CONCLUSION

An increased oesophageal diameter (> 11 mm) on chest HRCT is associated with pulmonary and oesophageal symptoms, more severe ILD, and lower DLco.

Computed Tomography of the Esophagus in Scleroderma and Lung Disease

Systemic sclerosis, or scleroderma, is a collagen vascular disease characterized by hardening of the skin and involvement of internal organs, most commonly the esophagus. The most frequent cause of death in these patients is lung disease. Esophageal dysfunction has been implicated in the pathogenesis of interstitial lung disease. We previously developed a standard for the esophageal diameter on chest computed tomography (CT) and hypothesized that patients with esophageal dilation would be more likely to have interstitial lung disease than those without. In this study, we test this in 121 systemic sclerosis patients with interstitial lung disease and 48 of those without interstitial lung disease. For controls, we evaluated 121 patients followed at a general pulmonary clinic and the previously studied normal healthy standards. This study demonstrated that esophageal dilation is common in systemic sclerosis patients (66.3% for the maximal esophageal diameter more than or equal to 15 mm), that systemic sclerosis patients with interstitial lung disease have more dilated esophagi than those without interstitial lung disease (median 19.4 mm vs. 14.1 mm), and that esophageal parameters are negatively correlated with pulmonary function. We also found that patients from general pulmonary clinic were more likely to have dilated esophagi than normal controls (median 12.1 mm vs. 9.7 mm). The CT measurement of esophageal diameter may be a useful marker of patients at risk for developing lung disease.

Pulmonary involvement in systemic sclerosis

Systemic sclerosis (SSc) is a multi-systemic autoimmune disease that mainly affects the skin, lungs, gastrointestinal tract, heart and kidneys. Pulmonary disease in patients with SSc is strongly associated with mortality. The mechanisms involved into its pathophysiology include the activation of autoimmune cells and hyperplasia of fibroblasts with an increased capacity to produce collagen and diminished collagen breakdown. Although pulmonary biopsy is the gold standard for the diagnosis of interstitial lung disease in SSc, the most commonly used method is high-resolution computed tomography due to its high sensitivity and specificity. Herein, a comprehensive review on the pulmonary involvement in SSc is presented highlighting the radiologic-pathologic correlations.

Correlation of delta high-resolution computed tomography (HRCT) score with delta clinical variables in early systemic sclerosis (SSc) patients

BACKGROUND

The correlation of changes (delta: Δ) of high-resolution computed tomography (HRCT) score with the Δ of other clinical variables has not been well studied. The purpose of this study was to determine the correlation of Δ HRCT score with Δ percent predicted forced vital capacity (%pFVC), Δ modified Rodnan Skin Score (mRSS), Δ erythrocyte sedimentation rate (ESR), and Δ percent of oxygen saturation at room air (%SpO₂) in patients with early systemic sclerosis (SSc).

METHODS

We used an inception cohort of early-SSc patients seen at the Rheumatology Clinic, Chiang Mai University, Thailand, between January 2010 and June 2014. All patients underwent HRCT at study entry and every 12 months thereafter. Thirty-one SSc patients who underwent pulmonary function test (PFT) within 12 weeks of their corresponding HRCT at baseline and last visit were identified. The extent of ground glass (GG), lung fibrosis (Fib), bronchiectasis (B), and honeycombing (HC) was scored, and then aggregated to produce a total (t) HRCT score.

RESULTS

Mean ± SD age and disease duration from non-Raynaud's phenomenon (NRP) to undergo HRCT at baseline were 52.2±8.8 years and 11.7±7.1 months, respectively. Seventeen (54.8%) patients were female and 20 (64.5%) were classified as dcSSc. The mean ± SD interval between the two HRCT tests was 16.0±7.2 months. The Δ HRCT scores [total fibrosis scores (t-Fib), total bronchiectasis scores (t-B), and total HRCT score (t-HRCT) scores] and Δ mRSS, but not Δ %pFVC, showed significant change over the observation period. We found significant correlation of Δ total honeycombing scores (t-HC) with Δ ESR (r=-0.44, P<0.05), and Δ t-Fib with Δ %SpO₂ (r=-0.38, P<0.05). However, no significant correlation of any Δ HRCT scores with Δ %pFVC and Δ mRSS were observed.

CONCLUSIONS

In this study, the changes in the HRCT scores were greater than %pFVC; this, along with their correlations with the changes in ESR and %SpO₂, suggest that HRCT scores are a useful and sensitive method for monitoring disease progression in early SSc-related ILD (SSc-ILD).

Computer-Aided Tomographic Analysis of Interstitial Lung Disease (ILD) in Patients with Systemic Sclerosis (SSc). Correlation with Pulmonary Physiologic Tests and Patient-Centred Measures of Perceived Dyspnea and Functional Disability

Objectives

This study was designed (a) to evaluate an improved quantitative lung fibrosis score based on a computer-aided diagnosis (CaM) system in patients with systemic sclerosis (SSc),—related interstitial lung disease (SSc-ILD), (b) to investigate the relationship between physiologic parameters (forced vital capacity [FVC] and single-breath diffusing capacity for carbon monoxide [DLCO]), patient-centred measures of dyspnea and functional disability and CaM and visual reader-based (CoVR) methods, and (c) to identify potential surrogate measures from quantitative and visual HRCT measurement.

Methods

126 patients with SSc underwent chest radiography, HRCT and PFTs. The following patient-centred measures were obtained: modified Borg Dyspnea Index (Borg score), VAS for breathing, and Health Assessment Questionnaire-Disability Index (HAQ-DI). HRCT abnormalities were scored according to the conventional visual reader-based score (CoVR) and by a CaM. The relationships among the HRCT scores, physiologic parameters (FVC and DLCO, % predicted) results and patient-centred measures, were calculated using linear regression analysis and Pearson’s correlation. Multivariate regression models were performed to identify the predictor variables on severity of pulmonary fibrosis.

Results

Subjects with limited cutaneous SSc had lower HAQ-DI scores than subjects with diffuse cutaneous SSc (p <0.001). CaM and CoVR scores were similar in the 2 groups. In univariate analysis, a strong correlation between CaM and CoVR was observed (p <0.0001). In multivariate analysis the CaM and CoVR scores were predicted by DLco, FVC, Borg score and HAQ-DI. Age, sex, disease duration, anti-topoisomerase antibodies and mRSS were not significantly associated with severity of pulmonary fibrosis on CaM- and CoVR methods.

Conclusions

Although a close correlation between CaM score results and CoVR total score was found, CaM analysis showed a more significant correlation with DLco (more so than the FVC), patient-centred measures of perceived dyspnea and functional disability. Computer-aided tomographic analysis is computationally efficient, and in combination with physiologic and patient-centred measures, it could allow a means for accurately assessing and monitoring the disease progression or response to therapy.

Esophageal dilatation and interstitial lung disease in systemic sclerosis: A cross-sectional study

OBJECTIVE

A patulous esophagus on high-resolution computed tomography (HRCT) of the thorax is frequently observed in patients with systemic sclerosis (SSc). Microaspiration has been purported to play a role in the development and progression of SSc interstitial lung disease (ILD), but studies examining the role of microaspiration in SSc ILD have yielded conflicting results. This study was conducted to determine the association between esophageal diameter and SSc ILD.

METHODS

A cross-sectional study of Northwestern Scleroderma Registry patients with available HRCT exams was conducted. The predictor variable was the widest esophageal diameter (WED) on HRCT, and the primary and secondary outcome variables were radiographic ILD and pulmonary function tests respectively. The degree of radiographic ILD was assessed using a semi-quantitative score adapted from published methods. Estimated regression coefficients adjusted for age, sex, race, body mass index, smoking; SSc disease subtype, serum autoantibodies, and disease duration; modified Rodnan skin score, proton pump inhibitor, and immune suppressant medication use and erythrocyte sedimentation rate were calculated.

RESULTS

A total of 270 subjects were studied. In the adjusted analyses, there were positive associations between WED and total ILD score (β = 0.27; 95% CI: 0.09-0.41), fibrosis (β = 0.15; 95% CI: 0.07-0.23), and ground glass opacities (β = 0.12; 95% CI: 0.04-0.20); there were negative associations between WED and FVC % predicted (β = -0.42; 95% CI: -0.69 to -0.13), and adjusted DLCO % predicted (β = -0.45; 95% CI: -0.80 to -0.09) after adjusting for potential confounders.

CONCLUSIONS

Increasing esophageal diameter on HRCT in patients with SSc is associated with more severe radiographic ILD, lower lung volumes, and lower DLCO % predicted. Longitudinal studies are needed to determine if esophageal dilatation is associated with the incidence and/or progression of ILD in patients with SSc.

Comparison of clinical and serological parameters in female and male patients with systemic sclerosis

OBJECTIVES

The course of systemic sclerosis (SSc) can differ in female and male patients. According to the literature the incidence rates of diffuse cutaneous SSc, scleroderma renal crisis and digital ulceration are higher in male patients. The aim of the study was to compare selected clinical and serological parameters in male and female patients with SSc.

MATERIAL AND METHODS

The study encompassed 101 European Caucasian patients with SSc, including 23 men, hospitalized in the Department of Rheumatology. Patients fulfilled the American Rheumatism Association (ARA) classification criteria for SSc. The study groups of men and women were assessed according to the SSc subtype, incidence of internal organ involvement and presence of antinuclear antibodies considered SSc markers.

RESULTS

Diffuse cutaneous (dc) SSc was observed more commonly in men than in women (13/23 vs. 25/78; p = 0.03). The time from the development of Raynaud's phenomenon to the diagnosis was significantly shorter in male compared to female patients (3.2 ±4.7 vs. 7.5 ±7.1; p = 0.01). The incidence of scleroderma renal crisis (SRC) was significantly higher (3/23 vs. 2/78; p = 0.04) and of other calcifications significantly lower in the male group compared to the female group (1/23 vs. 20/78; p = 0.02).

CONCLUSIONS

We concluded that the incidence of dcSSc is higher in men compared to women. The time from the development of Raynaud's phenomenon to the diagnosis is shorter in the male compare to female group. The incidence of SRC is higher, whereas that of calcifications is lower in SSc men. The serological profiles of female and male patients with SSc are comparable.

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.