Background Prognosis in connective tissue disease associated interstitial lung disease (CTD-ILD) is influenced by the underlying diagnosis and chest imaging pattern. Usual interstitial pneumonia (UIP), non-specific interstitial pneumonia (NSIP), and fibrotic hypersensitivity pneumonitis (fHP) patterns can be found across all CTD-ILD subtypes although their impact on disease evolution and treatment response is unclear. Objectives Our goal was to examine the association of lung imaging pattern with CTD-ILD progression, mortality, and immunosuppression response. Methods 615 patients with CTD-ILD enrolled in the Canadian Registry for Pulmonary Fibrosis had high-resolution chest computed tomography (HRCT) from their first ILD clinic visit reviewed in standardized multidisciplinary discussion. All CTD diagnoses were rheumatologist-confirmed. Experienced chest radiologists blinded to clinical data categorized each case into five groups: UIP, NSIP, organizing pneumonia (OP), fHP, and other patterns. Longitudinal percent-predicted forced vital capacity (FVC) and transplant-free survival were compared between imaging groups using linear mixed effects and Cox proportional hazards models adjusted for age, sex, smoking pack-years, and baseline FVC. Linear mixed effects models were used to compare pre- and post-treatment rate of FVC decline in patients with ≥6 months follow-up before and after treatment with mycophenolate, azathioprine, rituximab, cyclophosphamide, and/or tocilizumab. UIP was the reference group for all comparisons. Results The most frequent CTD subtypes were systemic sclerosis (SSc) (33%), rheumatoid arthritis (RA) (20%), and idiopathic inflammatory myopathy (IIM) (16%) with NSIP pattern present in 54% of all CTD-ILD (Table 1). On multivariable analyses among all CTD-ILD patients, NSIP was associated with a slower rate of FVC decline by 1.1%/year (0.2, 1.9) and a lower mortality HR (95%CI) of 0.65 (0.45, 0.93) compared to UIP. OP was also associated with a slower rate of FVC decline by 3.5%/year (2.0, 4.9) and a lower mortality HR (95%CI) of 0.18 (0.05, 0.57) compared to UIP. In contrast, fHP had a higher mortality HR (95%CI) of 1.58 (1.01, 2.40). The rate of FVC decline after treatment was not significantly different compared to pre-treatment in the UIP group but was slower in the NSIP group by 2.1%/year (1.4, 2.8). Subgroup analyses in RA-ILD and SSc-ILD showed the persistence of fHP having a higher mortality compared to UIP in RA-ILD. Conclusion The presence of an NSIP pattern was associated with improved outcomes and immunosuppression response compared to UIP in the overall CTD-ILD group. The findings of fHP associated with worse survival compared to UIP in CTD-ILD and in the RA-ILD are novel. These findings need to be further confirmed in disease specific cohorts and randomized trials of immunosuppression in patients with CTD-ILD. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests Boyang Zheng: None declared, Daniel-Costin Marinescu: None declared, cameron hague: None declared, Nestor Muller: None declared, darra murphy: None declared, Andrew Churg: None declared, Joanne Wright: None declared, Amna Al-Arnawoot: None declared, Ana-Maria Bilawich: None declared, patrick bourgouin: None declared, Gerald Cox: None declared, celine durand: None declared, Tracy Elliot: None declared, Jen Ellis: None declared, Jolene Fisher Consultant of: Boehringer-Ingelheim, AstraZeneca, Derek Fladeland: None declared, Amanda Grant-Orser: None declared, Gillian Goobie Grant/research support from: Boehringer Ingelheim, Zachary Guenther: None declared, Ehsan Haider: None declared, Nathan Hambly Speakers bureau: Boehringer Ingelheim, Grant/research support from: Boehringer Ingelheim, Janssen, Roche, James Huynh: None declared, Kerri Johannson Consultant of: Boehringer-Ingelheim, Hoffman-La Roche Ltd, geoff karjala: None declared, Nasreen Khalil: None declared, Martin Kolb Speakers bureau: Roche, Novartis, Boehringer Ingelheim, Grant/research support from: Boehringer Ingelheim, Pieris, Roche, Jonathon Leipsic Speakers bureau: GE Healthcare, Philips Healthcare, Stacey Lok Speakers bureau: Boehringer Ingelheim, sarah macisaac: None declared, micheal mcinnis: None declared, Helene Manganas Grant/research support from: Boehringer Ingelheim Canada, Hoffmann La Roche, Galapagos, BMS, Veronica Marcoux Grant/research support from: Astra Zeneca,Roche,Boehringer Ingelheim, John Mayo: None declared, julie morisset Speakers bureau: Roche, Boehringer Ingelheim, Ciaran Scallan: None declared, Tony Sedlic: None declared, shane shapera Consultant of: AstraZeneca, Boehringer Ingelheim, Hoffman LaRoche, Kelly Sun: None declared, victoria tan: None declared, Alyson Wong: None declared, Christopher Ryerson Speakers bureau: Boehringer Ingelheim, Hoffmann-La Roche, Astra Zeneca, Consultant of: Boehringer Ingelheim, Hoffmann-La Roche, Astra Zeneca.

Background Bronchoalveolar lavage (BAL) cellular analysis is often recommended during the initial diagnostic evaluation of fibrotic ILD. Despite recommendation for its use, between-center heterogeneity exists and supportive data concerning the clinical utility and correlation of BAL findings with radiologic features or patterns remains sparse. Research Question In patients with fibrotic ILD, are BAL findings associated with radiologic features, patterns, and clinical diagnoses? Methods Patients with fibrotic ILD who underwent BAL for diagnostic evaluation and enrolled in the prospective Canadian Registry for Pulmonary Fibrosis were re-reviewed in a standardized multidisciplinary discussion (MDD). BAL was categorized according to guideline-recommended thresholds, and also using thresholds of lymphocytosis>20% and neutrophils>4.5%. High-resolution computed tomography (HRCT) scans were scored (blinded to clinical data) for specific features and percentage lung involvement. Radiologists classified HRCTs according to guideline-defined patterns for idiopathic pulmonary fibrosis (IPF) and fibrotic hypersensitivity pneumonitis (fHP), then MDD diagnoses were assigned, considering all available data. Results Bronchoscopy with cellular analysis was performed in 209/1593 (13%) patients. Lymphocyte% was weakly negatively correlated with total fibrosis% (r=-0.16, p=0.023) but not statistically significantly correlated with ground glass opacity% (r=0.01, p=0.94). A mixed BAL pattern was the most frequent in all radiologic patterns (range 45% to 69%), with a minority classifiable according to BAL guidelines. BAL lymphocytosis appeared with similar frequency across HRCT patterns of fHP (21%) and UIP (18%). Only 5% of patients with MDD-based fHP had a guideline defined isolated lymphocytosis >15%. Interpretation BAL cellular analyses did not significantly correlate with radiologic features, guideline patterns, or MDD-based diagnoses. Ground glass opacities are often interpreted to represent pulmonary inflammation, but were not associated with BAL lymphocytosis in this cohort.

To assess the accuracy of computed tomography (CT) in the recognition of bronchiectasis, CT was performed in 11 patients with clinical findings strongly suggestive of this diagnosis. In two patients, CT showed extensive bilateral cystic and varicose bronchiectasis, and bronchography was considered unwarranted. In four patients, bilateral, and in five, unilateral bronchograms were obtained. Correlation was made between the CT and bronchographic findings in these 13 lungs. In only six bronchograms did CT give an accurate assessment of the presence and extent of disease. In five, the diagnosis of cylindrical and varicose bronchiectasis was missed on CT. In two, CT suggested the diagnosis of cylindrical bronchiectasis but the bronchogram was normal. It was concluded that CT may be useful in the diagnosis of cystic bronchiectasis, but is unreliable in detecting cylindrical and varicose changes. Bronchography, therefore, remains the definitive method for establishing the diagnosis, extent, and severity of bronchiectasis.

Misalignment of pulmonary vessels, with or without alveolar capillary dysplasia, is a rare cause of persistent pulmonary hypertension in the newborn.The prognosis is poor, with virtually all patients succumbing to unremitting hypoxaemic respiratory failure and death during the newborn period.We report the CT and histological findings of misplaced pulmonary arteries in a previously healthy young adult patient who presented with pulmonary arterial hypertension.Contiguous highresolution spiral CT angiography showed small pulmonary arteries coursing within the interlobular septa and enlarged central pulmonary arteries.Surgical lung biopsy demonstrated anomalous muscularised pulmonary arteries in the interlobular septa.This is, to our knowledge, the first report of misplaced pulmonary arteries presenting in an adult patient and may represent a forme fruste of the neonatal vascular anomaly.A possible association with pulmonary arterial hypertension is also suggested in this case.

Hypersensitivity pneumonitis (HP) is traditionally divided on clinical grounds into acute, subacute, and chronic stages. Most biopsy specimens come from patients in the subacute stage, in which there is a relatively mild, usually peribronchiolar, chronic interstitial inflammatory infiltrate, accompanied in most cases by poorly formed interstitial granulomas or isolated giant cells. However, the pathologic features in the chronic, ie, fibrotic stage, are poorly defined in the literature. These features are important to recognize because the chronic stage of HP is often associated with a poor prognosis. We reviewed 13 cases of chronic HP. Where information was available, exposures to the sensitizing agent had generally occurred over a long period of time. Three patterns of fibrosis were seen: 1) predominantly peripheral fibrosis in a patchy pattern with architectural distortion and fibroblast foci resembling, microscopically, usual interstitial pneumonia (UIP); 2) relatively homogeneous linear fibrosis resembling fibrotic nonspecific interstitial pneumonia (NSIP); and 3) irregular predominantly peribronchiolar fibrosis. In some instances, mixtures of the UIP-like and peribronchiolar patterns were found. In all cases, the presence of scattered poorly formed granulomas, or isolated interstitial giant cells, or sometimes only Schaumann bodies indicated the correct diagnosis. In 7 cases, areas of typical subacute HP were present as well. High-resolution CT scans showed variable patterns ranging from severe fibrosis, in some instances with an upper zone predominance, to predominantly ground glass opacities with peripheral reticulation. We conclude that, at the level of morphology, chronic HP may closely mimic UIP or fibrotic NSIP. If no areas of subacute HP are evident, the presence of isolated giant cells, poorly formed granulomas, or Schaumann bodies is crucial to arriving at the correct diagnosis, and the finding of peribronchiolar fibrosis may be helpful. Despite the presence of extensive fibrosis, some patients responded to removal from exposure and steroid therapy.

Drug-induced lung disease is an increasingly common cause of morbidity and mortality. The diagnosis is based on clinical history and consistent radiologic findings. Lung biopsy is performed in a small percentage of cases. High-resolution CT may demonstrate parenchymal abnormalities in patients with normal radiographs and provides a better depiction of the pattern and distribution of findings. Knowledge of the most common high-resolution CT manifestations and the corresponding histologic patterns is important for early recognition and proper management of drug-induced lung disease.

OBJECTIVE. The purpose of this study was to evaluate the high-resolution CT findings of drug-induced eosinophilic pneumonias.CONCLUSION. Drug-induced eosinophilic pneumonias usually manifest as areas of consolidation and ground-glass opacity most commonly involving the outer third of the lungs.

OBJECTIVE. The purposes of our study were to determine the prevalence of mediastinal lymphadenopathy in idiopathic interstitial pneumonias, correlate their presence with high-resolution CT (HRCT) findings, and assess the potential value of mediastinal lymphadenopathy in the differential diagnosis of idiopathic interstitial pneumonias.MATERIALS AND METHODS. The study included 206 consecutive patients from three medical centers with pathologically proven idiopathic pulmonary fibrosis (n = 136), nonspecific interstitial pneumonia (NSIP) (n = 47), cryptogenic organizing pneumonia (COP) (n = 16), respiratory bronchiolitis-interstitial lung disease (RB-ILD) (n = 5), and desquamative interstitial pneumonia (DIP) (n = 2). HRCT scans were retrospectively reviewed for the presence of mediastinal lymphadenopathy (short-axis diameter, >= 10 rum), predominant parenchymal pattern, and extent of disease.RESULTS. Mediastinal lymphadenopathy was seen in 139 (67%) of 206 patients, including 90 (66%) of 136 with idiopathic pulmonary fibrosis, 38 (81%) of 47 with NSIP, six (38%) of 16 with COP, and five (71%) of seven with RB-ILD or DIP. The presence of enlarged nodes was less common in COP than in the other idiopathic interstitial pneumonias (p = 0.04). No significant difference was found in the prevalence of lymphadenopathy in patients with predominant ground-glass opacity (53%) or predominant reticulation (40%). The extent of parenchymal abnormalities was 25-50% in 74 patients (53%), 50-75% in 30 (22%), < 25% in 22 (16%), and > 75% in 13 (9%). A positive correlation between the extent of disease and presence of lymphadenopathy was seen in patients with NSIP (p = 0.01).CONCLUSION. Mediastinal lymphadenopathy is a common feature in idiopathic interstitial pneumonias, being slightly less common in COP than in the other idiopathic interstitial pneumonias. The presence of lymphadenopathy therefore has limited value in the differential diagnosis. In patients with idiopathic pulmonary fibrosis, the presence of lymph node enlargement did not correlate to any specific HRCT pattern or to the extent of disease.

Myeloid leukemias are clonal malignancies characterized by the presence of increased numbers of immature myeloid cells in the marrow and peripheral blood. Pulmonary involvement by myeloid leukemia is relatively uncommon and seen mainly in patients with severe disease. The most common form of pulmonary involvement consists of leukemic infiltration along the lymphatics in the peribronchovascular, septal, and pleural interstitial tissue. Less common manifestations include myeloid sarcoma, leukostasis, leukemic cell lysis pneumopathy, and hyperleukocytic reaction. The radiological manifestations of pulmonary leukemic cell infiltration and leukostasis consist mainly of bilateral thickening of the peribronchovascular interstitium and interlobular septa, a pattern that resembles that of interstitial pulmonary edema. The radiological manifestations of leukemic cell lysis pneumopathy and hyperleukocytic reaction consist of symmetric bilateral areas of consolidation. This manuscript reviews the histological and radiological intrathoracic manifestations of myelogenous leukemias.

The aim of this study was to describe the high-resolution CT scan findings in five patients with AIDS and pulmonary infection due to Rhodococcus e qui. The study included five patients with AIDS and proven R. equi infection. The CT scans were reviewed by two observers. The patients included four men and one woman ranging from 39 years to 49 years in age (mean 42 years). The findings included areas of consolidation (n=5) with single (n = 1) or multiple cavitation (n = 4), ground-glass opacities (n = 5), centrilobular nodules (n = 3), small centrilobular nodular opacities (n=3) and "tree in bud" opacities (n=3). None of the patients had pleural effusion or lymph node enlargement. The most common high-resolution CT manifestations of R. equi infection consist of areas of consolidation with cavitation, ground-glass opacities, nodules and a tree-in-bud pattern.

AIM: To assess the relationship between initial CT pattern and serial changes in CT findings and pulmonary function tests (PFTs) in patients with non-specific interstitial pneumonia (NSIP).MATERIALS AND METHODS: Serial high resolution (HR) CTs and PFTs were retrospectively analyzed in 38 cases of histologically proven NSIP, including 4 with cellular NSIP, 13 with mixed cellular and fibrotic NSIP, and 21 with fibrotic NSIP. The presence and extent of various CT findings were assessed. A fibrosis index (defined as the ratio of the extent of a reticular/honeycomb pattern to the overall extent of abnormal parenchyma) was derived.RESULTS: The predominant CT pattern was reticular/honeycomb in 27 (84%) cases and ground-glass/consolidation in 6 (16%) cases. Between scans, mean disease extent reduced by 5.2%. Disease extent reduced by > 10% in 13 (34%) and increased by > 10% in 6 (16%) patients. Histopathotogical subtype of NSIP did not correlate with individual CT pattern, predominant pattern, fibrosis index or serial change in disease extent on CT or PFTs. Response on follow-up CT was associated with fibrosis index, predominant pattern and extent of consolidation on initial CT.CONCLUSION: In NSIP disease, progression on CT correlates with the predominant CT pattern, fibrosis index, and extent of consolidation but not with histopathological subtype. An inflammatory (ground-glass/consolidation) predominant pattern is associated with better outcome in terms of disease extent on HRCT. (C) 2005 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.