Predictive potential of MRI in differentiating the predominant component in biphasic pleural mesothelioma.

PURPOSE: To assess the potential of apparent diffusion coefficient (ADC) values derived from diffusion weighted (DW) MRI preoperatively to predict the predominant histologic component among biphasic pleural mesothelioma (PM) tumors. METHODS: ADC maps were generated from DW MRI scans. Histology and predominant component of biphasic PM were confirmed following surgical resection. Statistical analyses were done with R (R Foundation for Statistical Computing, Vienna, Austria). Average ADC values corresponding to epithelioid- and sarcomatoid-predominant tumors were compared. ADC thresholding was accomplished by recursive partitioning and confirmed with ROC analysis. RESULTS: Eighty-four patients with biphasic PM's, 69 (82 %) epithelioid-predominant (BE) and 15(18 %) sarcomatoid-predominant (BS) tumors were evaluated. Thirty-eight (45 %) patients underwent extrapleural pneumonectomy (EPP), 39 (46 %) had extended pleural decortication (ePDC) and 7 (8 %) had pleural decortication (PDC). ADC values ranged between 0.696 x 10-3 to 1.921 x 10-3 mm2/s. BE tumors demonstrated significantly higher ADC values than BS tumors (p = 0.026). ADC values above 0.94 x 10-3 mm2/s were associated with a significant increase of relative risk of being in group BE over group BS (relative risk: 1.47, 95 %CI: 1.05-2.06, p = 0.027) CONCLUSION: Average ADC values of BE tumors were higher than BS tumors and the two groups can be separated by a cut off value of 0.94 X 10-3 mm2/s.

The International Association for the Study of Lung Cancer Pleural Mesothelioma Staging Project: Proposal for Revision of the TNM Stage Groupings in the Forthcoming (Ninth) Edition of the TNM Classification for Pleural Mesothelioma.

INTRODUCTION: The eighth edition of the TNM classification of pleural mesothelioma (PM) saw substantial changes in T and N components and stage groupings. The International Association for the Study of Lung Cancer collected data into a multinational database to further refine this classification. This ninth edition proposal incorporates changes proposed in the clinical (c)T component but not the pathologic T component, to include size criteria, and further refines TNM stage groupings for PM. METHODS: Data were submitted through electronic data capture or batch transfer from institutional databases. Survival was measured from diagnosis date. Candidate stage groups were developed using a recursive partitioning and amalgamation algorithm applied to all cM0 cases for clinical stage and subsequently for pathologic stage. Cox models were developed to estimate survival for each stage group. RESULTS: Of 3598 submitted cases, 2192 were analyzable for overall clinical stage and 445 for overall pathologic stage. Recursive partitioning and amalgamation generated survival tree on overall survival outcomes restricted to cM0, with newly proposed (ninth edition) cT and cN component-derived optimal stage groupings of stage I (T1N0), II (T1N1; T2N0), IIIA (T1N2; T2N1/2; any T3), IIIB (any T4), and IV (any M1). Although cT and pathologic T descriptors are different in the ninth edition, aligning pathologic stage groupings with clinical stage produced better discrimination than did retaining eighth edition pathologic stage groupings. CONCLUSIONS: To our knowledge, this revision of the clinical TNM classification for PM is the first to incorporate the measurement-based proposed changes in cT category. The pathologic TNM aligns with clinical TNM.

The International Association for the Study of Lung Cancer Mesothelioma Staging Project: Proposals for the "N" Descriptors in the Forthcoming Ninth Edition of the TNM Classification for Pleural Mesothelioma.

INTRODUCTION: The International Association for the Study of Lung Cancer developed an international database to inform potential revisions in the ninth edition of the TNM classification of diffuse pleural mesothelioma (PM). This study analyzed the clinical and pathologic N categories to determine whether revisions were indicated relative to the eighth edition staging system. METHODS: Of 7338 PM cases diagnosed from 2013 to 2022 and 3598 met all inclusion criteria for planned analyses. Data on 2836 patients without metastases were included in this study. Overall survival (OS) was measured from date of diagnosis. Patients were included regardless of whether they received neoadjuvant treatment. For the pathologic N analysis, patients who underwent resection (extrapleural pneumonectomy or pleurectomy/decortication) were included. N subgroups were analyzed and OS assessed by the Kaplan-Meier method. RESULTS: The existing eighth edition N categories were performed adequately in the ninth edition data set. A median OS advantage was noted for clinical and pathologic N0 versus N1 patients: 23.2 versus 18.5 and 33.8 versus 25.0 months, respectively. Patients with resected pN0 had a 3-year OS of 48%. No difference in OS was noted for single- versus multiple-station nodal metastases. The number of nodal stations sampled at the time of resection was not associated with a difference in OS. CONCLUSIONS: Data regarding clinical and pathologic N categories corroborate those used in the eighth edition. No changes in the N categories are recommended in the ninth edition of PM staging system.

Circulating SMRP and CA-125 before and after pleurectomy decortication for pleural mesothelioma.

BACKGROUND: Tumor recurrence remains the main barrier to survival after surgery for pleural mesothelioma (PM). Soluble mesothelin-related protein (SMRP) and cancer antigen 125 (CA-125) are established blood-based biomarkers for monitoring PM. We prospectively studied the utility of these biomarkers after pleurectomy decortication (PD). METHODS: Patients who underwent PD and achieved complete macroscopic resection with available preoperative SMRP levels were included. Tumor marker levels were determined within 60 days of three timepoints: (1) preoperation, (2) post-operation, and (3) recurrence. RESULTS: Of 356 evaluable patients, 276 (78%) had recurrence by the end of follow-up interval. Elevated preoperative SMRP levels were associated with epithelioid histology (p < 0.013), advanced TNM (p < 0.001) stage, and clinical stage (p < 0.001). Preoperative CA-125 levels were not significantly associated with clinical covariates. Neither biomarker was associated with survival or disease-free survival. With respect to nonpleural and nonlymphatic recurrences, mean SMRP levels were elevated in patients with pleural (p = 0.021) and lymph node (p = 0.042) recurrences. CA-125 levels were significantly higher in patients with abdominal (p < 0.001) and lymph node (p = 0.004) recurrences. Among patients with all three timepoints available, we observed an average decrease in SMRP levels by 1.93 nmol/L (p < 0.001) postoperatively and again an average increase at recurrence by 0.79 nmol/L (p < 0.001). There were no significant changes in levels of CA-125 across the study timepoints (p = 0.47). CONCLUSIONS: Longitudinal changes in SMRP levels corresponded with a radiographic presence of disease in a subset of patients. SMRP surveillance could aid in detection of local recurrences, whereas CA-125 could be helpful in recognizing abdominal recurrences.

Radiology: Cardiothoracic Imaging Highlights 2023.

Radiology: Cardiothoracic Imaging publishes novel research and technical developments in cardiac, thoracic, and vascular imaging. The journal published many innovative studies during 2023 and achieved an impact factor for the first time since its inaugural issue in 2019, with an impact factor of 7.0. The current review article, led by the Radiology: Cardiothoracic Imaging trainee editorial board, highlights the most impactful articles published in the journal between November 2022 and October 2023. The review encompasses various aspects of coronary CT, photon-counting detector CT, PET/MRI, cardiac MRI, congenital heart disease, vascular imaging, thoracic imaging, artificial intelligence, and health services research. Key highlights include the potential for photon-counting detector CT to reduce contrast media volumes, utility of combined PET/MRI in the evaluation of cardiac sarcoidosis, the prognostic value of left atrial late gadolinium enhancement at MRI in predicting incident atrial fibrillation, the utility of an artificial intelligence tool to optimize detection of incidental pulmonary embolism, and standardization of medical terminology for cardiac CT. Ongoing research and future directions include evaluation of novel PET tracers for assessment of myocardial fibrosis, deployment of AI tools in clinical cardiovascular imaging workflows, and growing awareness of the need to improve environmental sustainability in imaging. Keywords: Coronary CT, Photon-counting Detector CT, PET/MRI, Cardiac MRI, Congenital Heart Disease, Vascular Imaging, Thoracic Imaging, Artificial Intelligence, Health Services Research © RSNA, 2024.

The International Association for the Study of Lung Cancer Mesothelioma Staging Project: Proposals for Revisions of the "T" Descriptors in the Forthcoming Ninth Edition of the TNM Classification for Pleural Mesothelioma.

INTRODUCTION: The primary tumor (T) component in the eighth edition of pleural mesothelioma (PM) staging system is based on pleural involvement and extent of invasion. Quantitative assessment of pleural tumor has been found to be prognostic. We explored quantitative and qualitative metrics to develop recommendations for T descriptors in the upcoming ninth edition of the PM staging system. METHODS: The International Association for the Study of Lung Cancer prospectively collected data on patients with PM. Sum of maximum pleural thickness (Psum) was recorded. Optimal combinations of Psum and eighth edition cT descriptors were assessed using recursive binary splitting algorithm, with bootstrap resampling to correct for the adaptive nature of the splitting algorithm, and validated in the eighth edition data. Overall survival (OS) was calculated by the Kaplan-Meier method and differences in OS assessed by the log-rank test. RESULTS: Of 7338 patients submitted, 3598 were eligible for cT analysis and 1790 had Psum measurements. Recursive partitioning identified optimal cutpoints of Psum at 12 and 30 mm, which, in combination with extent of invasion, yielded four prognostic groups for OS. Fmax greater than 5 mm indicated poor prognosis. cT4 category (based on invasion) revealed similar performance to eighth edition. Three eighth edition descriptors were eliminated based on low predictive accuracy. Eighth edition pT descriptors remained valid in ninth edition analyses. CONCLUSION: Given reproducible prognostication by Psum, size criteria will be incorporated into cT1 to T3 categories in the ninth edition. Current cT4 category and all pT descriptors will be maintained, with reclassification of fissural invasion as pT2.

What's new in thoracic oncology.

Many changes have occurred in the field of thoracic surgery over the last several years. In this review, we will discuss new diagnostic techniques for lung cancer, innovations in surgery, and major updates on latest treatment options including immunotherapy. All these have significantly started to change our approach toward the management of lung cancer and have great potential to improve the lives of our patients afflicted with this disease.

Virtual Residency Interviews- A Survival Guide and Lessons Learnt.

With the outbreak of Coronavirus Disease 2019 (COVID-19) pandemic, the residency programs were required to conduct virtual/online interviews for recruitment of candidates for their residency programs. While both programs and the candidates had challenges, with the abrupt transition of interviews to online platform, there were some perceived benefits by the applicants. This paper will further review the pros and cons, the challenges and the changes brought about by the online transformation of residency interviews and conclude with tips to the residency applicants and lessons learnt from this transition. Although, residency programs are considering going back to in-person interviews, they may continue to offer virtual interview as well to the candidates in the future.

Imaging Follow-Up of Nonsurgical Therapies for Lung Cancer: AJR Expert Panel Narrative Review.

Lung cancer continues to be the most common cause of cancer-related death worldwide. In the past decade, with the implementation of lung cancer screening programs and advances in surgical and nonsurgical therapies, the survival of patients with lung cancer has increased, as has the number of imaging studies that these patients undergo. However, most patients with lung cancer do not undergo surgical re-section, because they have comorbid disease or lung cancer in an advanced stage at diagnosis. Nonsurgical therapies have continued to evolve with a growing range of systemic and targeted therapies, and there has been an associated evolution in the imaging findings encountered at follow-up examinations after such therapies (e.g., with respect to posttreatment changes, treatment complications, and recurrent tumor). This AJR Expert Panel Narrative Review describes the current status of nonsurgical therapies for lung cancer and their expected and unexpected imaging manifestations. The goal is to provide guidance to radiologists regarding imaging assessment after such therapies, focusing mainly on non-small cell lung cancer. Covered therapies include systemic therapy (conventional chemotherapy, targeted therapy, and immunotherapy), radiotherapy, and thermal ablation.

Autoantibodies against citrullinated and native proteins and prediction of rheumatoid arthritis-associated interstitial lung disease: A nested case-control study.

Background: To identify fine specificity anti-citrullinated protein antibodies (ACPA) associated with incident rheumatoid arthritis-associated interstitial lung disease (RA-ILD). Methods: This nested case-control study within the Brigham RA Sequential Study matched incident RA-ILD cases to RA-noILD controls on time of blood collection, age, sex, RA duration, and rheumatoid factor status. A multiplex assay measured ACPA and anti-native protein antibodies from stored serum prior to RA-ILD onset. Logistic regression models calculated odds ratios (OR) with 95% confidence intervals (CI) for RA-ILD, adjusting for prospectively-collected covariates. We estimated optimism-corrected area under the curves (AUC) using internal validation. Model coefficients generated a risk score for RA-ILD. Findings: We analyzed 84 incident RA-ILD cases (mean age 67 years, 77% female, 90% White) and 233 RA-noILD controls (mean age 66 years, 80% female, 94% White). We identified six fine specificity antibodies that were associated with RA-ILD. The antibody isotypes and targeted proteins were: IgA2 to citrullinated histone 4 (OR 0.08 per log-transformed unit, 95% CI 0.03-0.22), IgA2 to citrullinated histone 2A (OR 4.03, 95% CI 2.03-8.00), IgG to cyclic citrullinated filaggrin (OR 3.47, 95% CI 1.71-7.01), IgA2 to native cyclic histone 2A (OR 5.52, 95% CI 2.38-12.78), IgA2 to native histone 2A (OR 4.60, 95% CI 2.18-9.74), and IgG to native cyclic filaggrin (OR 2.53, 95% CI 1.47-4.34). These six antibodies predicted RA-ILD risk better than all clinical factors combined (optimism-corrected AUC=0·84 versus 0·73). We developed a risk score for RA-ILD combining these antibodies with the clinical factors (smoking, disease activity, glucocorticoid use, obesity). At 50% predicted RA-ILD probability, the risk scores both without (score=2·6) and with (score=5·9) biomarkers achieved specificity ≥93% for RA-ILD. Interpretation: Specific ACPA and anti-native protein antibodies improve RA-ILD prediction. These findings implicate synovial protein antibodies in the pathogenesis of RA-ILD and suggest clinical utility in predicting RA-ILD once validated in external studies. Funding: National Institutes of Health.

A Large-Scale Proteomics Resource of Circulating Extracellular Vesicles for Biomarker Discovery in Pancreatic Cancer.

Pancreatic cancer has the worst prognosis of all common tumors. Earlier cancer diagnosis could increase survival rates and better assessment of metastatic disease could improve patient care. As such, there is an urgent need to develop biomarkers to diagnose this deadly malignancy earlier. Analyzing circulating extracellular vesicles (cEVs) using 'liquid biopsies' offers an attractive approach to diagnose and monitor disease status. However, it is important to differentiate EV-associated proteins enriched in patients with pancreatic ductal adenocarcinoma (PDAC) from those with benign pancreatic diseases such as chronic pancreatitis and intraductal papillary mucinous neoplasm (IPMN). To meet this need, we combined the novel EVtrap method for highly efficient isolation of EVs from plasma and conducted proteomics analysis of samples from 124 individuals, including patients with PDAC, benign pancreatic diseases and controls. On average, 912 EV proteins were identified per 100µL of plasma. EVs containing high levels of PDCD6IP, SERPINA12 and RUVBL2 were associated with PDAC compared to the benign diseases in both discovery and validation cohorts. EVs with PSMB4, RUVBL2 and ANKAR were associated with metastasis, and those with CRP, RALB and CD55 correlated with poor clinical prognosis. Finally, we validated a 7-EV protein PDAC signature against a background of benign pancreatic diseases that yielded an 89% prediction accuracy for the diagnosis of PDAC. To our knowledge, our study represents the largest proteomics profiling of circulating EVs ever conducted in pancreatic cancer and provides a valuable open-source atlas to the scientific community with a comprehensive catalogue of novel cEVs that may assist in the development of biomarkers and improve the outcomes of patients with PDAC.

Considerations for Imaging of Malignant Pleural Mesothelioma: A Consensus Statement from the International Mesothelioma Interest Group.

Malignant pleural mesothelioma (MPM) is an aggressive primary malignancy of the pleura that presents unique radiologic challenges with regard to accurate and reproducible assessment of disease extent at staging and follow-up imaging. By optimizing and harmonizing technical approaches to imaging MPM, the best quality imaging can be achieved for individual patient care, clinical trials, and imaging research. This consensus statement represents agreement on harmonized, standard practices for routine multimodality imaging of MPM, including radiography, computed tomography, 18F-2-deoxy-D-glucose positron emission tomography, and magnetic resonance imaging, by an international panel of experts in the field of pleural imaging assembled by the International Mesothelioma Interest Group. In addition, modality-specific technical considerations and future directions are discussed. A bulleted summary of all technical recommendations is provided.

Image-guided video-assisted thoracoscopic surgery (iVATS): a single center experience and review.

Lung cancer screening techniques using low-dose computed tomography (LDCT) scans have improved over the last decade. This means that there is an increased rate of detection of small, often non-palpable, nodules and ground-glass opacities. Obtaining a definitive diagnosis of these nodules using techniques such as percutaneous image-guided biopsy or intraoperative localization is challenging, and these nodules have traditionally undergone routine surveillance. Image-guided video-assisted thoracoscopic surgery (iVATS), which is performed in a hybrid operating room, has made it more feasible to biopsy and resect these nodules. The first thoracic surgery hybrid operative room was introduced at our institution at Brigham and Women's Hospital. Herein, we describe our experience implementing this technique including the methods we used to train key personnel such as radiologists, surgeons, and anesthesiologists to ensure that this technique successfully translated to a clinical setting. We review the benefits of iVATS, which includes decreased rate of fiducial dislodgement, real-time imaging which facilitates successful fiducial placement, and smaller sized resection of lung parenchyma. We will also describe the comparisons between traditional diagnostic methods and iVATS, patient selection criteria and important technical details. Some centers describe alternative techniques for several of the technical aspects, including patient positioning, which we also mention. Lastly, we describe adverse events after iVATS, which are comparable to those seen after a standard VATS.

Serum proteomic profiling of rheumatoid arthritis-interstitial lung disease with a comparison to idiopathic pulmonary fibrosis.

Although interstitial lung disease (ILD) causes significant morbidity and mortality in rheumatoid arthritis (RA), it is difficult to predict the development or progression of ILD, emphasising the need for improved discovery through minimally invasive diagnostic tests. Aptamer-based proteomic profiling was used to assess 1321 proteins from 159 patients with rheumatoid arthritis with interstitial lung disease (RA-ILD), RA without ILD, idiopathic pulmonary fibrosis and healthy controls. Differential expression and gene set enrichment analyses revealed molecular signatures that are strongly associated with the presence and severity of RA-ILD and provided insight into unexplored pathways of disease. These warrant further study as non-invasive diagnostic tools and future therapeutic targets.

Imaging in pleural mesothelioma: A review of the 15th International Conference of the International Mesothelioma Interest Group.

Imaging of mesothelioma plays a role in all aspects of patient management, including disease detection, staging, evaluation of treatment options, response assessment, pre-surgical evaluation, and surveillance. Imaging in this disease impacts a wide range of disciplines throughout the healthcare enterprise. Researchers and clinician-scientists are developing state-of-the-art techniques to extract more of the information contained within these medical images and to utilize it for more sophisticated tasks; moreover, image-acquisition technology is advancing the inherent capabilities of these images. This paper summarizes the imaging-based topics presented orally at the 2021 International Conference of the International Mesothelioma Interest Group (iMig), which was held virtually from May 7-9, 2021. These topics include an update on the mesothelioma staging system, novel molecular targets to guide therapy in mesothelioma, special considerations and potential pitfalls in imaging mesothelioma in the immunotherapy setting, tumor measurement strategies and their correlation with patient survival, tumor volume measurement in MRI and CT, CT-based texture analysis for differentiation of histologic subtype, diffusion-weighted MRI for the assessment of biphasic mesothelioma, and the prognostic significance of skeletal muscle loss with chemotherapy.

Pleurectomy Decortication in the Treatment of Malignant Pleural Mesothelioma: Encouraging Results and Novel Prognostic Implications Based on Experience in 355 Consecutive Patients.

OBJECTIVE: We report a series of 355 consecutive patients treated over 9 years in a single institution with intended PDC. BACKGROUND: Surgery for MPM has shifted from extra-pleural pneumonectomy to PDC with the goal of MCR. METHODS: Clinical and outcome data were reviewed. Kaplan-Meier estimators and log rank test were used to compare the overall survival, and logistic regression models were used. RESULTS: MCR was achieved in 304. There were 223 males, median age was 69 and histology was epithelioid in 184. The 30 and 90-day mortality were 3.0% and 4.6%.Most complications were low grade. Prolonged air leak in 141, deep venous thrombosis in 64, Atrial fibrillation in 42, chylothorax in 24, Empyema in 23, pneumonia in 21, Hemothorax in 12 and pulmonary embolus in 8. Median/5-year survival were 20.7 months/17.9% in the intent-to-treat cohort and 23.2months/21.2% in the MCR group. The survivals were best for patients with Tlstage and epithelioid histology (69.8months/54.1%). In a multivariable analysis, factors that were found to be associated with longer patient overall survival included epithelioid histology, T stage, quantitative clinical stage/tumor volume staging, adjuvant chemotherapy, intraoperative heated chemo, female sex, and length of stay shorter than 14 days. CONCLUSIONS: PDC is feasible with low mortality and is associated with manageable complication rates. 5-year survival of patients undergoing PDC with MCR in multi-modality setting is approaching 25% depending on quantitative and clinical stage, sex and histological subtype and is better than PDC without- MCR.

The Virtual Homeroom: Utility and Benefits of Small Group Online Learning in the COVID-19 Era.

OBJECTIVE: During COVID-19, Harvard Medical School pivoted to online learning. A large student cohort took a completely virtual Radiology clerkship with daily programming including virtual small group teaching sessions or "homerooms." MATERIALS AND METHODS: One hundred and eleven medical students were divided into 12 virtual small group sessions which emphasized foundational concepts. Uniform teaching materials were used across all homerooms in order to deepen understanding and allow insight into the working methods of radiologists. Students evaluated the homeroom learning and teachers for utility and benefit to their educational experience. RESULTS: Most students (93%) felt the homerooms provided an educational benefit and reinforced topics studied (77%). Most students (84%) felt the leaders created an environment conducive to learning. Despite being virtual, students were able to form interpersonal connections with the homeroom leaders. CONCLUSIONS: Incorporating virtual small group learning can be a valuable component of a virtual or hybrid Radiology clerkship, solidifying foundational concepts with the homeroom leaders playing a major role. While developed by necessity due to COVID-19, virtual small group learning with engaged leaders is an educational strategy whose benefit can continue even as there is return to in-person learning.

Mediastinal Masses, Anesthetic Interventions, and Airway Compression in Adults: A Prospective Observational Study.

BACKGROUND: Central airway occlusion is a feared complication of general anesthesia in patients with mediastinal masses. Maintenance of spontaneous ventilation and avoiding neuromuscular blockade are recommended to reduce this risk. Physiologic arguments supporting these recommendations are controversial and direct evidence is lacking. The authors hypothesized that, in adult patients with moderate to severe mediastinal mass-mediated tracheobronchial compression, anesthetic interventions including positive pressure ventilation and neuromuscular blockade could be instituted without compromising central airway patency. METHODS: Seventeen adult patients with large mediastinal masses requiring general anesthesia underwent awake intubation followed by continuous video bronchoscopy recordings of the compromised portion of the airway during staged induction. Assessments of changes in anterior-posterior airway diameter relative to baseline (awake, spontaneous ventilation) were performed using the following patency scores: unchanged = 0; 25 to 50% larger = +1; more than 50% larger = +2; 25 to 50% smaller = -1; more than 50% smaller = -2. Assessments were made by seven experienced bronchoscopists in side-by-side blinded and scrambled comparisons between (1) baseline awake, spontaneous breathing; (2) anesthetized with spontaneous ventilation; (3) anesthetized with positive pressure ventilation; and (4) anesthetized with positive pressure ventilation and neuromuscular blockade. Tidal volumes, respiratory rate, and inspiratory/expiratory ratio were similar between phases. RESULTS: No significant change from baseline was observed in the mean airway patency scores after the induction of general anesthesia (0 [95% CI, 0 to 0]; P = 0.953). The mean airway patency score increased with the addition of positive pressure ventilation (0 [95% CI, 0 to 1]; P = 0.024) and neuromuscular blockade (1 [95% CI, 0 to 1]; P < 0.001). No patient suffered airway collapse or difficult ventilation during any anesthetic phase. CONCLUSIONS: These observations suggest a need to reassess prevailing assumptions regarding positive pressure ventilation and/or paralysis and mediastinal mass-mediated airway collapse, but do not prove that conventional (nonstaged) inductions are safe for such patients.

Screening for preclinical parenchymal lung disease in rheumatoid arthritis.

OBJECTIVES: Pulmonary disease is a common extraarticular manifestation of RA associated with increased morbidity and mortality. No current strategies exist for screening this at-risk population for parenchymal lung disease, including emphysema and interstitial lung disease (ILD). METHODS: RA patients without a diagnosis of ILD or chronic obstructive pulmonary disease underwent prospective and comprehensive clinical, laboratory, functional and radiological evaluations. High resolution CT (HRCT) scans were scored for preclinical emphysema and preclinical ILD and evaluated for other abnormalities. RESULTS: Pulmonary imaging and/or functional abnormalities were identified in 78 (74%) of 106 subjects; 45% had preclinical parenchymal lung disease. These individuals were older with lower diffusion capacity but had similar smoking histories compared with no disease. Preclinical emphysema (36%), the most commonly detected abnormality, was associated with older age, higher anti-cyclic citrullinated peptide antibody titres and diffusion abnormalities. A significant proportion of preclinical emphysema occurred among never smokers (47%) with a predominantly panlobular pattern. Preclinical ILD (15%) was not associated with clinical, laboratory or functional measures. CONCLUSION: We identified a high prevalence of undiagnosed preclinical parenchymal lung disease in RA driven primarily by isolated emphysema, suggesting that it may be a prevalent and previously unrecognized pulmonary manifestation of RA, even among never smokers. As clinical, laboratory and functional evaluations did not adequately identify preclinical parenchymal abnormalities, HRCT may be the most effective screening modality currently available for patients with RA.