Radiological and histopathological features and treatment response by subtypes of interstitial pneumonia with autoimmune features: A prospective, multicentre cohort study.

BACKGROUND: Patients with idiopathic interstitial pneumonia (IIP) have a favourable prognosis when they have interstitial pneumonia with autoimmune features (IPAF). However, precise IPAF-related findings from high-resolution computed tomography (HRCT) and lung histopathological specimens and the treatment response have not been fully determined. Therefore, this study was conducted to evaluate the relationship between findings on HRCT or lung histopathological specimens and the progression of interstitial pneumonia in patients with IPAF. METHODS: This multicentre cohort study prospectively enrolled consecutive patients with IIP. At the diagnosis of IIP, we systematically evaluated 74 features suggestive of connective tissue diseases and followed them up. HRCT, lung specimens, serum antibodies, and the clinical course were also evaluated. RESULTS: Among 222 patients with IIP, 26 (11.7%) fulfilled the IPAF criteria. During a median observation period of 36 months, patients with IPAF showed better survival than those without IPAF (p = 0.034). While histopathological findings were not related to IPAF, nonspecific interstitial pneumonia (NSIP) with organizing pneumonia (OP) overlap was the most prevalent HRCT pattern (p < 0.001) and the consolidation opacity was the most common radiological finding in IPAF (p = 0.017). Furthermore, in patients with IPAF, the diagnosis of COP or NSIP with OP overlap was associated with a higher increase in %FVC in 1 year than in those with idiopathic pulmonary fibrosis, NSIP, or unclassifiable IIP (p = 0.002). CONCLUSIONS: This study shows the presence of consolidation opacity on HRCT and the diagnosis of COP or NSIP with OP overlap are associated with IPAF and its favourable treatment response in patients with IPAF.

Non-contrast computed tomography-based radiomics for staging of connective tissue disease-associated interstitial lung disease.

Rationale and introduction: It is of significance to assess the severity and predict the mortality of patients with connective tissue disease-associated interstitial lung disease (CTD-ILD). In this double-center retrospective study, we developed and validated a radiomics nomogram for clinical management by using the ILD-GAP (gender, age, and pulmonary physiology) index system. Materials and methods: Patients with CTD-ILD were staged using the ILD-GAP index system. A clinical factor model was built by demographics and CT features, and a radiomics signature was developed using radiomics features extracted from CT images. Combined with the radiomics signature and independent clinical factors, a radiomics nomogram was constructed and evaluated by the area under the curve (AUC) from receiver operating characteristic (ROC) analyses. The models were externally validated in dataset 2 to evaluate the model generalization ability using ROC analysis. Results: A total of 245 patients from two clinical centers (dataset 1, n = 202; dataset 2, n = 43) were screened. Pack-years of smoking, traction bronchiectasis, and nine radiomics features were used to build the radiomics nomogram, which showed favorable calibration and discrimination in the training cohort {AUC, 0.887 [95% confidence interval (CI): 0.827-0.940]}, the internal validation cohort [AUC, 0.885 (95% CI: 0.816-0.922)], and the external validation cohort [AUC, 0.85 (95% CI: 0.720-0.919)]. Decision curve analysis demonstrated that the nomogram outperformed the clinical factor model and radiomics signature in terms of clinical usefulness. Conclusion: The CT-based radiomics nomogram showed favorable efficacy in predicting individual ILD-GAP stages.

Computed Tomography-Based Deep Learning Model for Assessing the Severity of Patients With Connective Tissue Disease-Associated Interstitial Lung Disease.

OBJECTIVES: This study aimed to develop a computed tomography (CT)-based deep learning model for assessing the severity of patients with connective tissue disease (CTD)-associated interstitial lung disease (ILD). METHODS: The retrospective study included 298 CTD-ILD patients between January 2018 and May 2022. A deep learning-based RDNet model was established (1610 fully annotated CT images for training and 402 images for validation). The model was used to automatically classify and quantify 3 radiologic features (ground glass opacities [GGOs], reticulation, and honeycombing), along with a volumetric sum of 3 areas (ILD%). As a control, we used 4 previously defined CT threshold methods to calculate the ILD assessment index. The Spearman rank correlation coefficient ( r ) evaluated the correlation between various indicators and the lung function index in the remaining 184 CTD-ILD patients who were staged according to the gender-age-physiology (GAP) system. RESULTS: The RDNet model accurately identified GGOs, reticulation, and honeycombing, with corresponding Dice indexes of 0.784, 0.782, and 0.747, respectively. A total of 137 patients were at GAP1 (73.9%), 36 patients at GAP2 (19.6%), and 11 patients at GAP3 (6.0%). The percentages of reticulation and honeycombing at GAP2 and GAP3 were markedly elevated compared with those at GAP1 ( P < 0.001). The percentage of GGOs was not significantly different among the GAP stages ( P = 0.62). As the GAP stage increased, all lung function indicators tended to decrease, and the composite physiologic index (CPI) indicated an upward tendency. The percentage of honeycombs moderately correlated with the percentage of diffusing capacity of the lung for carbon monoxide (DLco%) ( r = -0.58, P < 0.001) and CPI ( r = 0.63, P < 0.001). The ILD assessment index calculated by the CT threshold method (-260 to -600 Hounsfield units) had a low correlation with DLco% and CPI (DLco%: r = -0.42, P < 0.001; CPI: r = 0.45, P < 0.001). CONCLUSIONS: The RDNet model can quantify GGOs, reticulation, and honeycombing of chest CT images in CTD-ILD patients, among which honeycombing had the most significant effect on lung function indicators. In addition, this model provided good clinical utility for evaluating the severity of CTD-ILD.

Spectrum of high-resolution computed tomography pattern in lungs in patients with connective tissue disorders.

Background: Connective tissue disease associated with interstitial lung disease, or CT-ILD, is a lung condition that affects a large number of patients with a connective tissue disease. Objective: Our aim in this study is to correlation between images of high-resolution computed tomography (HRCT) of different connective tissue diseases associated interstitial lung diseases (CTD-ILDs). Methods: We shall be aiming to investigate the feasibility of HRCT imaging and thereby avoid lung biopsy in such patients. Results: Rheumatoid arthritis predominantly presented with usual interstitial pneumonia (UIP) (47.8%), followed by nonspecific interstitial pneumonia (NSIP) (30.4%). Mixed connective tissue disorder predominantly presented with NSIP and UIP (42.8%), followed by organizing pneumonia (OP) (14.2%). Systemic lupus erythematosus predominantly presented with UIP (38.8%), followed by NSIP (27.7%). Sjogren's syndrome predominantly presented with lymphocytic interstitial pneumonia (40%), followed by UIP (26.6%). Scleroderma predominantly presented with UIP (45.4%), followed by NSIP (36.4%). Sarcoidosis predominantly presented with UIP (75%), followed by NSIP (25%). Dermatomyositis predominantly presented with NSIP (50%), followed by UIP and OP each (25%). Conclusion: Both clinicians and radiologists should be aware of the expected evolution of HRCT changes in a variety of CT-ILDs.

Résumé Contexte: La maladie du tissu conjonctif associée à la maladie pulmonaire interstitielle, ou CT ILD, est une affection pulmonaire qui affecte un grand nombre de patients atteints d'une maladie du tissu conjonctif. Objectif: Notre objectif dans cette étude est de mettre en corrélation des images de tomodensitométrie à haute résolution (HRCT) de différentes maladies du tissu conjonctif associées à des maladies pulmonaires interstitielles (CTD ILDs). Méthodes: Notre objectif sera d'étudier la faisabilité de l'imagerie HRCT et d'éviter ainsi la biopsie pulmonaire chez ces patients. Résultats: La polyarthrite rhumatoïde se présentait principalement avec une pneumonie interstitielle habituelle (PUI) (47,8 %), suivie d'une pneumonie interstitielle non spécifique (NSIP) (30,4 %). Trouble mixte du tissu conjonctif présenté principalement avec NSIP et UIP (42,8 %), suivi d'une pneumonie organisée (OP) (14,2 %). Le lupus érythémateux disséminé présentait principalement une UIP (38,8 %), suivie d'une NSIP (27,7 %). Le syndrome de Sjogren présentait principalement une pneumonie interstitielle lymphocytaire (40 %), suivie d'une PUI (26,6 %). La sclérodermie se présentait principalement avec l'UIP (45,4 %), suivi du NSIP (36,4 %). La sarcoïdose se présentait principalement avec l'UIP (75 %), suivi du NSIP (25 %). La dermatomyosite se présentait principalement avec NSIP (50 %), suivi par UIP et OP chacun (25 %). Conclusion: Les cliniciens et les radiologues doivent être conscients de l'évolution attendue des changements HRCT dans une variété d'ILD CT. Mots-clés: Tissu conjonctif, CT ILDs, tomodensitométrie haute résolution, poumon interstitiel.

A computed tomography-based radiomics nomogram for predicting overall survival in patients with connective tissue disease-associated interstitial lung disease.

OBJECTIVES: Accurate prognostic prediction is beneficial for the management of patients with connective tissue disease-associated interstitial lung disease (CTD-ILD). The purpose of the present study was to develop and validate a nomogram using clinical features and computed tomography (CT) based radiomics features to predict overall survival (OS) in patients with CTD-ILD, and to assess the incremental prognostic value the radiomics might add to clinical risk factors. MATERIALS & METHODS: Patients from two clinical centers with CTD-ILD were enrolled in the present retrospective study. A radiomics signature, a clinical model and a combined nomogram were developed and assessed in the cohorts. The incremental value of radiomics signature to the clinical independent risk factors in survival prediction was evaluated. The models were externally validated to evaluate the model generalization ability. RESULTS: A total of 215 patients (mean age, 53 years ± 14 [standard deviation], 45 men) were evaluated. Patients with higher radiomics scores had higher mortality risk than those with lower radiomics scores (Hazard ratio, 12.396; 95% CI, 3.364-45.680; P < 0.001). The combined nomogram showed better predictive capability than the clinical model did with higher C-indices (0.800, 0.738, 0.742 vs. 0.747, 0.631, 0.587 in the training, internal- and external-validation cohort, respectively), time-AUCs and overall net-benefit. CONCLUSION: The radiomics signature is a potential prognostic biomarker of CTD-ILD and add incremental value to the clinical independent risk factors. The combined nomogram can provide a more accurate estimation of OS than the clinical model for CTD-ILD patients. CLINICAL RELEVANCE STATEMENT: The developed combined nomogram showed accurate prognostic prediction performance, which is beneficial for the management of CTD-ILD patients. It also proved radiomics could extract prognostic information from CT images.

Nailfold capillaroscopy findings of interstitial pneumonia with autoimmune features.

BACKGROUND/AIMS: We evaluated nailfold capillaroscopy (NFC) of interstitial pneumonia with autoimmune features (IPAF) and compared it with that of patients with connective tissue disease-interstitial lung disease (CTD-ILD) and idiopathic interstitial pneumonia (IIP). METHODS: Patients with newly diagnosed as ILD were evaluated using NFC. Baseline demographic, clinical, serological, and high-resolution CT findings were collected. NFC was semi-quantitatively scored with six domains ranging from 0 to 18. In addition, the overall patterns (scleroderma/non-scleroderma patterns) were determined. RESULTS: A total of 81 patients (31 with CTD-ILD, 18 with IPAF, and 32 with IIP) were included. The non-specific interstitial pneumonia pattern was the most common ILD pattern in the CTD-ILD and IPAF groups, whereas the usual interstitial pneumonia pattern was the most common in the IIP group. The semi-quantitative score of the CTD-ILD group was higher than that of the IPAF or IIP groups (5.8 vs 4.2 vs 3.0, p < 0.001, respectively). Giant capillaries and haemorrhages were more frequently present in the CTD-ILD and IPAF groups than in the IIP group. A scleroderma pattern was present in 27.8% of the IPAF group, whereas none of the IIP patients showed a scleroderma pattern. CONCLUSION: NFC findings may be useful in classifying patients with ILD into CTD-ILD/IPAF/IIP.

Classification of pulmonary sounds through deep learning for the diagnosis of interstitial lung diseases secondary to connective tissue diseases.

Early diagnosis of interstitial lung diseases secondary to connective tissue diseases is critical for the treatment and survival of patients. The symptoms, like dry cough and dyspnea, appear late in the clinical history and are not specific, moreover, the current approach to confirm the diagnosis of interstitial lung disease is based on high resolution computer tomography. However, computer tomography involves x-ray exposure for patients and high costs for the Health System, therefore preventing its use for a massive screening campaign in elder people. In this work we investigate the use of deep learning techniques for the classification of pulmonary sounds acquired from patients affected by connective tissue diseases. The novelty of the work consists of a suitably developed pre-processing pipeline for de-noising and data augmentation. The proposed approach is combined with a clinical study where the ground truth is represented by high resolution computer tomography. Various convolutional neural networks have provided an overall accuracy as high as 91% in the classification of lung sounds and have led to an overwhelming diagnostic accuracy in the range 91%-93%. Modern high performance hardware for edge computing can easily support our algorithms. This solution paves the way for a vast screening campaign of interstitial lung diseases in elder people on the basis of a non-invasive and cheap thoracic auscultation.

Prevalence, imaging patterns and risk factors of interstitial lung disease in connective tissue disease: a systematic review and meta-analysis.

INTRODUCTION: Interstitial lung disease (ILD) is a frequent manifestation of connective tissue disease (CTD) with substantial variability in prevalence and outcomes reported across CTD subtypes. This systematic review summarises the prevalence, risk factors and ILD patterns on chest computed tomography of CTD-ILD. METHODS: A comprehensive search was performed in Medline and Embase to identify eligible studies. Meta-analyses were completed using a random effects model to determine the pooled prevalence of CTD-ILD and ILD patterns. RESULTS: 11 582 unique citations were identified with 237 articles included. Pooled prevalence of ILD was 11% in rheumatoid arthritis (95% CI 7-15%), 47% in systemic sclerosis (44-50%), 41% in idiopathic inflammatory myositis (33-50%), 17% in primary Sjögren's syndrome (12-21%), 56% in mixed connective tissue disease (39-72%) and 6% in systemic lupus erythematosus (3-10%). Usual interstitial pneumonia was the most prevalent ILD pattern in rheumatoid arthritis (pooled prevalence of 46%), while nonspecific interstitial pneumonia was the most common ILD pattern in all other CTD subtypes (pooled prevalence range 27-76%). Across all CTDs with available data, positive serology and higher inflammatory markers were risk factors for development of ILD. DISCUSSION: We identified substantial variability in ILD across CTD subtypes suggesting that CTD-ILD is too heterogenous to be considered a single entity.

Case report of severe coronary artery tortuosity with coexisting connective tissue disease.

Coronary artery tortuosity (CAT) is frequently detected during coronary angiography or coronary electron-beam computed tomography angiography by cardiovascular interventionalists. In this article, we described the case of a 69-year-old female patient with recurrent chest discomfort for 1 month and recurrence 1 week ago, accompanied by emaciation, gastrointestinal discomfort, and low skin temperature at the extremities. After a series of tests, the patient was finally diagnosed with severe CAT and coexisting connective tissue disease. Accordingly, she was treated with conventional medications, and diet and lifestyle modifications. The symptoms of the patient resolved gradually after 1 year of follow-up. Although there is no unanimous conclusion on the pathogenesis and clinical characteristics of CAT, this disease may provide a clue to the diagnosis of connective tissue disease, and warrants exploration through further research.

Screening value of lung ultrasound in connective tissue disease related interstitial lung disease.

BACKGROUND: Interstitial lung disease (ILD) is a common pulmonary complication of connective tissue disease (CTD) that can lead to poor quality of life and prognosis. OBJECTIVES: To explore the screening value of lung ultrasound (LUS) for connective tissue disease-associated interstitial lung disease (CTD-ILD). METHODS: Data of patients with CTD were collected, and each patient underwent LUS, high-resolution computed tomography (HRCT), and pulmonary function tests. Considering HRCT is the gold standard for diagnosing CTD-ILD, patients were divided into CTD-ILD and CTD-non-ILD groups. The LUS and HRCT results were assessed using semiquantitative and Warrick scores, respectively. Pulmonary function results were also collected. Receiver operating characteristic (ROC) curves were used to evaluate the accuracy of LUS diagnosis. Spearman correlation analysis was used to analyze the correlation between LUS, HRCT, and lung function indices. RESULTS: A total of 88 patients (65 with CTD-ILD and 23 with CTD-non-ILD) were included in this study. The sensitivity and specificity of LUS for the diagnosis of CTD-ILD were 86.60% and 82.60%, respectively, which was consistent with the HRCT results (P < 0.05). The LUS results (total number of B-lines, frequency of B-line, pleural thickness, and pleural-line irregularity) were positively correlated with the HRCT Warrick score (r = 0.77, 0.76, 0.65 and 0.71, P < 0.05). CONCLUSIONS: LUS may be a promising tool for screening patients with CTD-ILD.

Progression and prognosis of interstitial pneumonia with autoimmune features: a longitudinal, prospective, multi-centre study.

OBJECTIVES: To evaluate the rate of progression towards specific autoimmune diseases (SADs) of a prospective, multi-centre cohort of patients classifiable as interstitial pneumonia with autoimmune features (IPAF). METHODS: IPAF patients were enrolled based on specific research criteria, and jointly followed by rheumatologists and pulmonologists for at least one year with clinical check-ups, serological exams including autoimmunity, capillaroscopy and high-resolution computed tomography (HRCT). Diagnostic assessment was repeated at least once a year, or earlier when deemed useful. RESULTS: We enrolled 191 IPAF patients through 95 different combinations of IPAF criteria. Of these, 24.1% progressed towards SAD, mainly in connective tissue diseases but also in microscopic polyangiitis. The IPAF patients who progressed were younger than stable IPAF patients (63±10 years vs. 68±9 years, p=0.002) and had a longer follow-up (36.9±18.7 vs. 29.3±15.7 months, p=0.007), but similar severity. No parameters were associated with overall progression, but some parameters were associated with the development of specific diagnoses: Sjögren's syndrome with positivity for SSA (p=0.007, χ2 7.4); idiopathic inflammatory myopathy with mechanic's hands (p=<0.0001, χ2 12.6), organizing pneumonia pattern (p=0.01, χ2 6.1), positivity for anti-Pm/scl (p=0.04 χ2 4.1) and anti-MDA5 (p=0.04, χ2 4.2); systemic sclerosis with palmar telangiectasias (p=<0.0001 2 18.3), positivity for anti-Scl70 (p=<0.0001 χ2 12.5) and anti-PM/Scl (p=0.001 χ2 10.1). CONCLUSIONS: IPAF patients had a rate of progression towards SAD similar to that reported in previous studies on undifferentiated connective tissue diseases, thus including some patients in which lung involvement could represent the first or even the sole clinical manifestation of a SAD.

Clinical and HRCT features of amyopathic dermatomyositis associated with interstitial lung disease: A retrospective study of 128 patients with connective tissue disease-related interstitial lung disease.

BACKGROUND: This study retrospectively analyzed the laboratory data and chest images of patients with amyopathic dermatomyositis associated with interstitial lung disease (ADM-ILD) and patients with other connective tissue disease-related ILDs (CTD-ILDs) to find a characteristic index for the early recognition of ADM-ILD and help clinicians consider the possibility of ADM-ILD as soon as possible. METHODS: In our cohort study, the records of 128 Chinese patients with CTD-ILD, including 33 ADM-ILD patients, 37 rheumatoid arthritis (RA)-ILD patients, 33 primary Sjogren's syndrome (pSS)-ILD patients, 14 systemic sclerosis (SSc)-ILD patients and 11 systemic lupus erythematosus (SLE)-ILD patients. The patients' clinical features, laboratory parameters, and chest HRCT findings were analyzed. RESULTS: ADM-ILD patients generally had significantly higher LDH (333.52±160.21 U/L), AST (66.21±83.66 U/L), and CK-MB (18.23±8.28 U/L) levels than other CTD-ILD patients. A total of 90.91% (30/33) of ADM-ILD patients had elevated LDH. Patients with ADM-ILD were more prone to organizing pneumonia radiologic patterns on chest HRCT scans than patients with other CTD-ILDs (χ2=37.39, p < 0.001) and were found in 18 of 33 ADM-ILD patients. Anti-MDA5 (45.45%) was the most commonly detected autoantibody in ADM-ILD patients, followed by anti-PL-7 (21.21%), anti-Jo-1 (12.12%), and anti-PL-12 (9.09%), and levels of ALT (96.93±119.79 vs. 17.50±6.218 U/L), AST (113.00±106.13 vs. 23.56±6.91 U/L), LDH (415.00±198.51 vs. 261.94±67.75 U/L) and CK-MB (22.57±5.91 vs. 14.61±8.36 U/L) were significantly higher in anti-MDA5-positive patients, but these patients had significantly lower WBC counts (4.82±2.61 vs. 7.14±3.00 × 109/L), lymphocyte counts (0.72±0.20 vs. 1.23±0.53 × 109/L), and ALB levels (31.90±4.76 vs. 35.49±4.71 g/L). CONCLUSIONS: ADM-ILD patients have higher serum LDH, AST and CK-MB levels, especially serum LDH levels, and are more prone to organizing pneumonia radiologic patterns on chest HRCT scans than other CTD-ILD patients. A high level of serum LDH with ILD may be a useful characteristic index for recognizing ADM-ILD.

CT predictors of outcomes in patients with connective tissue disease and progressive lung fibrosis.

PURPOSE: Progressive fibrosing interstitial lung disease (PF-ILD) is a phenotype defined by rapid clinical progression towards respiratory failure. While idiopathic pulmonary fibrosis is the archetype of PF-ILD, connective tissue disease associated interstitial lung disease (CTD-ILD) can also manifest as PF-ILD. Few studies have described the value of serial computed tomography (CT) in predicting clinical progression of ILD. We explore which single and serial clinical and radiographic variables, in particular serial CT variables and a novel variable, the right lower lobe anterior bronchial angle (RLL-ABA), best predict mortality, oxygen requirement, hospital admissions, and lung transplant in CTD-ILD. METHODS: This is a single-center retrospective study of 84 patients with a history of CTD-ILD. Cox survival analysis was used to predict two endpoints, all-cause mortality and composite negative outcomes (CNO): new oxygen requirement, respiratory admission, lung transplant, and death. RESULTS: On serial CT, change in pulmonary artery (PA) size and RLL-ABA were predictive of mortality and CNO, and change in fibrosis was predictive of mortality alone. On single CT, the extent of fibrosis, PA size, and PA to aorta ratio were predictive of mortality and CNO. Among clinical variables, oxygen requirement, forced vital capacity (FVC), change in FVC, and worsening shortness of breath were predictive of mortality and CNO, and diffusing capacity for carbon monoxide was predictive of mortality alone. CONCLUSIONS: In addition to clinical and single CT variables, serial CT measurements such as change in extent of fibrosis, PA size, PA to aorta ratio, and RLL-ABA were predictive of mortality and CNO.

Structured report improves radiology residents' performance in reporting chest high-resolution computed tomography: a study in patients with connective tissue disease.

PURPOSE To evaluate the performance of radiology residents (RRs) when using a dedicated structured report (SR) template for chest HRCT in patients with suspected connective tissue disease-interstitial lung disease (CTD-ILD), compared to the traditional narrative report (NR). METHODS We retrospectively evaluated 50 HRCT exams in patients with suspected CTD-ILD. A chest-devoted radiologist reported all the HRCT exams as the reference standard, pointing out pulmonary fibrosis findings (i.e., honeycombing, traction bronchiectasis, reticulation, and volume loss), presence and pattern of ILD, and possible other diagnoses. We divided four RRs into two groups according to their expertise level. In each group, RRs reported all HRCT examinations alternatively with NR or SR, noting each report's reporting time. The Cohen's Kappa, Wilcoxon, and McNemar tests were used for statistical analysis. RESULTS Regarding the pulmonary fibrosis findings, we found higher agreement between RRs and the reference standard reader when using SR than NR, regardless of their expertise level, except for volume loss.RRs' accuracy for "other diagnosis" was higher when using SR than NR, moving from 0.48 to 0.66 in the novel group (p = 0.035) and from 0.44 to 0.80 in the expertise group (p < 0.001). No differences in accuracy were found between ILD presence and ILD pattern. The reporting time was significantly lower (p = 0.001) when using SR than NR. CONCLUSION SR is of value in increasing the reporting of critical chest HRCT findings in the complex CTD-ILD scenario and should be used early and systematically during the residency.

Imaging of Pulmonary Manifestations of Connective Tissue Disease.

The majority of connective tissue diseases (CTDs) are multisystem disorders that are often heterogeneous in their presentation and do not have a single laboratory, histologic, or radiologic feature that is defined as the gold standard to support a specific diagnosis. Given this challenging situation, the diagnosis of CTD is a process that requires the synthesis of multidisciplinary data which may include patient clinical symptoms, serologic evaluation, laboratory testing, and imaging. Pulmonary manifestations of connective tissue disease include interstitial lung disease as well as multicompartmental manifestations. These CT imaging patterns and features of specific diseases will be discussed in this article.

Imaging of Lung Disease Associated with Connective Tissue Disease.

There is a well-known association between the connective tissue disorders (CTDs) and lung disease. In addition to interstitial lung disease, the CTDs may affect the air spaces and pulmonary vasculature. Imaging tests are important not only in diagnosis but also in management of these complex disorders. In the present review, key aspects of the imaging of CTD-reated diseases are discussed.

The role of PET/CT in connective tissue disorders: systemic sclerosis, Sjögren's syndrome and systemic lupus erythematosus.

Advanced imaging techniques are needed to help clinicians in the diagnosis, in the choice of the right time for therapeutic interventions or for modifications and monitoring of treatment response in patients with autoimmune connective tissue diseases. Nuclear medicine imaging, especially PET/CT and PET/MRI, may play an important role in detecting disease activity, assessing early treatment response as well as in clarifying the complex mechanisms underlying systemic sclerosis, Sjögren's syndrome or systemic lupus erythematosus. In addition, [18F]FDG PET/CT may help in excluding or detecting coexisting malignancies. Other more specific radiopharmaceuticals are being developed and investigated, targeting specific cells and molecules involved in connective tissue diseases. Further larger studies with standardized imaging protocol and image interpretation are strongly required before including PET/CT in the diagnostic work-up of subsets of patients with autoimmune connective tissue diseases.

Nailfold capillaroscopy: tips and challenges.

Although nailfold capillaroscopy (NFC) appears to have a bright future in clinical practice, the lack of familiarity with the technique and how to interpret its outcomes is major barriers which have made nailfold capillaroscopy an underutilized method in standard clinical practice. Traditional methods for assessment and measurement of capillary patterns, density, and blood flow are falling behind and face some challenges. In fact, there have been calls for improvement, hence the recent publication of the standardization of NFC by the EULAR Study Group on Microcirculation in Rheumatic Diseases. Nailfold capillaroscopy has the advantage of being a non-invasive technique that provides a window into the digital microcirculation. This paved the way for a rapidly growing interest in using capillaroscopy parameters as outcome measures in research. In standard clinical practice, whilst its main application is in the identification of an underlying systemic sclerosis spectrum disorder in patients presenting with Raynaud's phenomenon, its use has expanded to include other clinical features possibly suggestive of an underlying connective tissue disease. This article presents the challenges, provides tips, and highlights the exciting potential of nailfold capillaroscopy in standard practice.

Prognostic Significance of Small Pulmonary Vessel Alteration Measured by Chest Computed Tomography in Connective Tissue Diseases With Pulmonary Arterial Hypertension.

BACKGROUND: Pulmonary arterial hypertension (PAH) is characterized by structural alterations of pulmonary vessels. Few studies have explored the clinical significance of quantitative assessment of pulmonary small vessels by chest computed tomography (CT). Our aim was to assess whether the prognosis of connective tissue diseases (CTD)-PAH patients could be assessed through pulmonary small vessels measured by chest CT. METHODS: In all, 42 CTD-PAH patients diagnosed based on right heart catheterization were retrospectively investigated. All patients underwent a chest CT within 1 month before and after right heart catheterization examination. Main pulmonary artery (MPA) and the cross-sectional area of small pulmonary vessels <5 mm2 as a percentage of total lung area (%CSA <5) were measured. The primary endpoint was a composite clinical worsening endpoint. RESULTS: After a median follow-up time of 30.5 (interquartile range, 8.5 to 45.25) months, endpoint events occurred in 16 (38.1%) patients after 19.5 (interquartile range, 10.0 to 45.5) months. Cox univariate proportional hazard analysis showed that pulmonary vascular resistance, MPA diameter, and %CSA <5 were associated with the end point. A combination of MPA diameter and %CSA < 5 was the independent risk factor for the prognosis (hazard ratio, 2.180 [95% confidence interval, 1.405-3.383], P=0.001). Kaplan-Meier analysis showed that CTD-PAH patients satisfying %CSA < 5 of <0.382 and MPA >36.75 mm had the highest risk of experiencing the endpoint. CONCLUSION: Among the pulmonary vascular indicators measured by chest CT, in addition to MPA, %CSA < 5 may be a potential independent risk factor for poor long-term prognosis in Chinese CTD-PAH patients.