Imaging of interstitial lung disease

Influence of thoracic radiology training on classification of interstitial lung diseases

INTRODUCTION

Interpretation of high-resolution CT images plays an important role in the diagnosis and management of interstitial lung diseases. However, interreader variation may exist due to varying levels of training and expertise. This study aims to evaluate interreader variation and the role of thoracic radiology training in classifying interstitial lung disease (ILD).

METHODS

This is a retrospective study where seven physicians (radiologists, thoracic radiologists, and a pulmonologist) classified the subtypes of ILD of 128 patients from a tertiary referral center, all selected from the Interstitial Lung Disease Registry which consists of patients from November 2014 to January 2021. Each patient was diagnosed with a subtype of interstitial lung disease by a consensus diagnosis from pathology, radiology, and pulmonology. Each reader was provided with only clinical history, only CT images, or both. Reader sensitivity and specificity and interreader agreements using Cohen's κ were calculated.

RESULTS

Interreader agreement based only on clinical history, only on radiologic information, or combination of both was most consistent amongst readers with thoracic radiology training, ranging from fair (Cohen's κ: 0.2-0.46), moderate to almost perfect (Cohen's κ: 0.55-0.92), and moderate to almost perfect (Cohen's κ: 0.53-0.91) respectively. Radiologists with any thoracic training showed both increased sensitivity and specificity for NSIP as compared to other radiologists and the pulmonologist when using only clinical history, only CT information, or combination of both (p < 0.05).

CONCLUSIONS

Readers with thoracic radiology training showed the least interreader variation and were more sensitive and specific at classifying certain subtypes of ILD.

SUMMARY SENTENCE

Thoracic radiology training may improve sensitivity and specificity in classifying ILD based on HRCT images and clinical history.

Severe SARS-CoV-2 pneumonia: Clinical, functional and imaging outcomes at 4 months

Introduction

Given the pathophysiology of coronavirus disease 19 (COVID-19), persistent pulmonary abnormalities are likely.

Methods

We conducted a prospective cohort study in severe COVID-19 patients who had oxygen saturation < 94% and were primarily admitted to hospital. We aimed to describe persistent gas exchange abnormalities at 4 months, defined as decreased diffusing capacity of the lungs for carbon monoxide (DLco) and/or desaturation on the 6-minute walk test (6MWT), along with associated mechanisms and risk factors.

Results

Of the 72 patients included, 76.1% required admission to an intensive care unit (ICU), while 68.5% required invasive mechanical ventilation (MV). A total of 39.1% developed venous thromboembolism (VTE). After 4 months, 61.4% were still symptomatic. Functionally, 39.1% had abnormal carbon monoxide test results and/or desaturation on 6MWT; high-flow oxygen, MV, and VTE during the acute phase were significantly associated. Restrictive lung disease was observed in 23.6% of cases, obstructive lung disease in 16.7%, and respiratory muscle dysfunction in 18.1%. A severe initial presentation with admission to ICU (P = 0.0181), and VTE occurrence during the acute phase (P = 0.0089) were associated with these abnormalities. 41% had interstitial lung disease in computed tomography (CT) of the chest. Four patients (5.5%) displayed residual defects on lung scintigraphy, only one of whom had developed VTE during the acute phase (5.5%). The main functional respiratory abnormality (31.9%) was reduced capillary volume (Vc < 70%).

Conclusion

Among patients with severe COVID-19 pneumonia who were admitted to hospital, 61% were still symptomatic, 39% of patients had persistent functional abnormalities and 41% radiological abnormalities after 4 months. Embolic sequelae were rare but the main functional respiratory abnormality was reduced capillary volume. A respiratory check-up after severe COVID-19 pneumonia may be relevant to improve future management of these patients.

Impact of pulmonary interstitial lesions on efficacy and prognosis of EGFR-TKI-treated advanced non-small cell lung cancers

Background

This study aimed to assess the impact of pre-existing pulmonary interstitial lesions (PIL) on the efficacy and prognosis of patients with epidermal growth factor receptor (EGFR) mutant non-small cell lung cancer (NSCLC) treated with EGFR tyrosine kinase inhibitor (TKI).

Methods

Patients with advanced NSCLC harboring EGFR exon 19 deletion (E19 del) or exon 21 (E21) L858R were enrolled in this study. All patients underwent high resolution computed tomography (HRCT) chest scans prior to EGFR-TKI treatment. Pre-existing PIL was graded according to HRCT imaging (PIL 0, 1, 2, and 3). Cox proportional-hazards regression models were used to identify the prognostic factors for progression-free survival (PFS).

Results

A total of 134 eligible patients were enrolled. The overall objective response rate (ORR) and median PFS were 73.1% and 10.0 months (95% CI: 7.51–12.49), respectively. There were 62 (46.3%), 25 (18.7%), 28 (20.9%), and 19 (14.1%) cases of PIL grade 0, 1, 2, and 3, respectively, with median PFS and ORR of 12.9 months and 80.6%, 11.0 months and 72.0%, 10.0 months and 71.4%, and 7.0 months and 52.6%, respectively. Multivariate analysis showed that squamous cell carcinoma (vs. adenocarcinoma, HR =4.33), E21 L858R (vs. E19 del, HR =1.57), and PIL grade 3 (vs. grade 0–2, HR =1.60–2.48) were poor prognostic factors for PFS (P<0.05 for all).

Conclusions

Pre-existing PIL grade is an independent prognostic factor for predicting resistance to EGFR-TKIs in patients with EGFR-mutant advanced NSCLC. Higher PIL grade suggests higher risk of early progression.

A case report and literature review: previously excluded tuberculosis masked by amiodarone induced lung injury

Background

Amiodarone is an antiarrhythmic drug which is used to treat and prevent several dysrhythmias. This includes ventricular tachycardia and fibrillation, wide complex tachycardia, as well as atrial fibrillation (AF) and paroxysmal supraventricular tachycardia. Amiodarone may prove to be the agent of choice where the patient is hemodynamically unstable and unsuitable for direct current (DC) cardioversion. Although, it is not recommended for long-term use. The physician might encounter issues when differentiating amiodarone-induced lung toxicity with suspicion of interstitial lung disease, cancer or vasculitis. Adverse drug reactions are difficult to confirm and it leads to serious problems of pharmacotherapy.

Case presentation

A 78-year-old Caucasian male pensioner complaining of fever, dyspnea, malaise, non-productive cough, fatigue, weight loss, diagnosed with acute respiratory failure with a 16-year long history of amiodarone use and histologically confirmed temporal arteritis with long-term glucocorticosteroid (GCC) therapy.

Patient was treated for temporal arteritis with GCC for ~ 1 year, then fever and dyspnea occurred, and the patient was hospitalized for treatment of bilateral pneumonia. Chest X-ray and chest high resolution computed tomography (HRCT) indicated several possible diagnoses: drug-induced interstitial lung disease, autoimmune interstitial lung disease, previously excluded pulmonary TB. Amiodarone was discontinued. Antibiotic therapy for bilateral pneumonia was started. Fiberoptic bronchoscopy with bronchial washings and brushings was performed. Acid fast bacilli (AFB) were found on Ziehl-Nielsen microscopy and tuberculosis (TB) was confirmed (later confirmed to be Mycobacterium tuberculosis in culture), initial treatment for TB was started. After a few months of treating for TB, patient was diagnosed with pneumonia and sepsis, empiric antibiotic therapy was prescribed.

After reevaluation and M. Tuberculosis identification, the patient was referred to the Tuberculosis hospital for further treatment. After 6 months of TB treatment, pneumonia occurred which was complicated by sepsis. Despite the treatment, multiple organ dysfunction syndrome evolved and patient died. Probable cause of death: pneumonia and sepsis.

Conclusions

The current clinical case emphasizes issues that a physician may encounter in the differential diagnostics of amiodarone-induced lung toxicity with other lung diseases.

A case of pulmonary dialysis-related amyloidosis with reticular opacity of the lung in a patient undergoing long-term dialysis

Dialysis-related amyloidosis (DRA) is one of the most important complications in long-term dialysis patients. Pulmonary involvement in patients with DRA has been rarely described, and lung radiographic findings have not yet been reported. The most common chronic lung disease process in chronic dialysis patients is interstitial fibrosis. This is the first case report of DRA presenting in the lung in a manner resembling interstitial pneumonia. This case study suggests that interstitial pneumonia as a result of DRA should be considered when dyspnoea and reticular opacity of the lung are observed in patients undergoing long-term dialysis.

Utility of virtual bronchoscopy-guided transbronchial biopsy for the diagnosis of pulmonary sarcoidosis: report of two cases

Sarcoidosis is a multisystem granulomatous disease of unknown etiology that usually affects the lungs. Although flexible fiberoptic bronchoscopy with transbronchial lung biopsy (TBBx) has a high diagnostic yield in patients with pulmonary sarcoidosis, variously ranging from 40 to 90%, more invasive procedures often prove necessary. We report two cases of successful diagnosis of pulmonary sarcoidosis using a new technique that may increase the accuracy of TBBx. Previously described for diagnosis of peripheral lung cancer, this technique relies on real-time virtual bronchoscopic guidance to biopsy preselected peripheral areas of the lung preferentially affected by the disease using a pediatric bronchoscope. In each case, while procedures were performed under direct CT guidance allowing precise confirmation of the tip of the biopsy catheter, it is anticipated that this technique will be primarily used as a guide to bronchoscopic biopsies without the need for direct CT guidance, thus increasing routine utilization of multidetector low-dose high-resolution CT to improve histologic diagnosis.