High-resolution computed tomography and histopathological findings in hypersensitivity pneumonitis: a pictorial essay

Diagnostic Approach to Hypersensitivity Pneumonitis: A Report of Two Cases

Hypersensitivity pneumonitis (HP) is a bronchopulmonary granulomatosis of immunological mechanism, caused by an aberrant response to an inhaled exposure, which results in mostly T cell-mediated inflammation, granuloma formation, and fibrosis in some cases. The most common forms are bird breeder's disease and farmer's lung disease. The diagnosis of HP is based on the presence of compatible symptoms, the notion of exposure to antigens known to be pathogenic, and the existence of interstitial and bronchiolar images on the thoracic scan, lymphocytosis in the alveolar lavage, and precipitins. Chronic forms, in case of insidious exposure, especially in poultry, may evolve into pulmonary fibrosis with a poor prognosis. Through this work, we want to underline the frequency of this disease in our country, its heterogeneity as well as the difficult early diagnosis. Finally, we will investigate the therapeutic effect of corticosteroids in the early stages and the antifibrotic treatment in fibrotic forms.

Chest Imaging in the Diagnosis of Occupational Lung Diseases

Imaging plays a crucial role in the diagnosis and monitoring of occupational lung diseases (OLDs); however, the sensitivity and specificity of detection and diagnosis vary greatly depending on the imaging modality used. There is substantial overlap in appearance with non-occupation-related entities. OLDs should be considered in the differential even in the absence of a provided exposure history. Because many findings are not specific, a multidisciplinary approach is important in arriving at the diagnosis and will continue to be important as workplace-related pulmonary diseases evolve with changing industrial practices and workplace regulations.

Rare imaging findings of hypersensitivity pneumonitis: A case report

BACKGROUND

Hypersensitivity pneumonitis (HP) is an immune-mediated syndrome caused by allergen inhalation. High-resolution computed tomography (HRCT) of HP may show diffuse ground-glass opacity, centrilobular ground-glass nodules, areas of air-trapping, thin-walled cysts, or fibrotic changes.

CASE SUMMARY

A 47-year-old male patient went to the hospital complaining of cough and gradual aggravation of shortness of breath. HRCT of the lung showed that multiple nodules and ground-glass high-density shadows were present in both lungs. In addition, circular high-density shadows of various sizes were widely distributed in both lungs with relatively normal lung markings inside them. But other tests did not have a positive finding that can clarify the cause. Therefore, the patient underwent a lung biopsy. The pathological results showed that the lesions tended to be HP. After 4 mo of follow-up, the lesions in the patient's lungs were absorbed spontaneously, and the symptoms of cough and shortness of breath have disappeared. The review results suggested that the patient’s disease was self-healing, which was consistent with the characteristics of HP.

CONCLUSION

For some patients with HP, abnormal HRCT findings, such as the lesions in the lungs, can be absorbed on their own, which is an important clue in the diagnosis of the disease. Early diagnosis by lung biopsy is necessary when antigen exposure is unknown.

Idiopathic interstitial pneumonias: review of the latest American Thoracic Society/European Respiratory Society classification

The diagnosis of idiopathic interstitial pneumonias (IIPs) involves a multidisciplinary scenario in which the radiologist assumes a key role. The latest (2013) update of the IIP classification by the American Thoracic Society/European Respiratory Society proposed some important changes to the original classification of 2002. The novelties include the addition of a new disease (idiopathic pleuroparenchymal fibroelastosis) and the subdivision of the IIPs into four main groups: chronic fibrosing IIPs (idiopathic pulmonary fibrosis and nonspecific interstitial pneumonia); smoking-related IIPs (desquamative interstitial pneumonia and respiratory bronchiolitis-associated interstitial lung disease); acute or subacute IIPs (cryptogenic organizing pneumonia and acute interstitial pneumonia); rare IIPs (lymphoid interstitial pneumonia and idiopathic pleuroparenchymal fibroelastosis); and the so-called "unclassifiable" IIPs. In this study, we review the main clinical, tomographic, and pathological characteristics of each IIP.

Pulmonary thromboembolism: new diagnostic imaging techniques

The accurate diagnosis of pulmonary thromboembolism is essential to reducing the morbidity and mortality associated with the disease. The diagnosis of pulmonary thromboembolism is challenging because of the nonspecific nature of the clinical profile and the risk factors. Imaging methods provide the definitive diagnosis. Currently, the imaging method most commonly used in the evaluation of pulmonary thromboembolism is computed tomography. The recent development of dual-energy computed tomography has provided a promising tool for the evaluation of pulmonary perfusion through iodine mapping. In this article, we will review the importance of diagnosing pulmonary thromboembolism, as well as the imaging methods employed, primarily dual-energy computed tomography.

Utility of the inspiratory phase in high-resolution computed tomography evaluations of pediatric patients with bronchiolitis obliterans after allogeneic bone marrow transplant: reducing patient radiation exposure

OBJECTIVE

To evaluate the utility of the inspiratory phase in high-resolution computed tomography (HRCT) of the chest for the diagnosis of post-bone marrow transplantation bronchiolitis obliterans.

MATERIALS AND METHODS

This was a retrospective, observational, cross-sectional study. We selected patients of either gender who underwent bone marrow transplantation and chest HRCT between March 1, 2002 and December 12, 2014. Ages ranged from 3 months to 20.7 years. We included all examinations in which the HRCT was performed appropriately. The examinations were read by two radiologists, one with extensive experience in pediatric radiology and another in the third year of residency, who determined the presence or absence of the following imaging features: air trapping, bronchiectasis, alveolar opacities, nodules, and atelectasis.

RESULTS

A total of 222 examinations were evaluated (mean, 5.4 ± 4.5 examinations per patient). The expiratory phase findings were comparable to those obtained in the inspiratory phase, except in one patient, in whom a small uncharacteristic nodule was identified only in the inspiratory phase. Air trapping was identified in a larger number of scans in the expiratory phase than in the inspiratory phase, as was atelectasis, although the difference was statistically significant only for air trapping.

CONCLUSION

In children being evaluated for post-bone marrow transplantation bronchiolitis obliterans, the inspiratory phase can be excluded from the chest HRCT protocol, thus reducing by half the radiation exposure in this population.

Radiologist agreement on the quantification of bronchiectasis by high-resolution computed tomography

Objective

To evaluate radiologist agreement on the quantification of bronchiectasis by high-resolution computed tomography (HRCT).

Materials and Methods

The HRCT scans of 43 patients with bronchiectasis were analyzed by two radiologists, who used a scoring system to grade the findings. Kappa (κ) values and overall agreement were calculated.

Results

For the measurement and appearance of bronchiectasis, the interobserver agreement was moderate (κ = 0.45 and κ = 0.43, respectively), as was the intraobserver agreement (κ = 0.54 and κ = 0.47, respectively). Agreement on the presence of mucous plugging was fair, for central distribution (overall interobserver agreement of 68.3% and κ = 0.39 for intraobserver agreement) and for peripheral distribution (κ = 0.34 and κ = 0.35 for interobserver and intraobserver agreement, respectively). The agreement was also fair for peribronchial thickening (κ = 0.21 and κ = 0.30 for interobserver and intraobserver agreement, respectively). There was fair interobserver and intraobserver agreement on the detection of opacities (κ = 0.39 and 71.9%, respectively), ground-glass attenuation (64.3% and κ = 0.24, respectively), and cysts/bullae (κ = 0.47 and κ = 0.44, respectively). Qualitative analysis of the HRCT findings of bronchiectasis and the resulting individual patient scores showed that there was an excellent correlation between the observers (intraclass correlation coefficient of 0.85 and 0.81 for interobserver and intraobserver agreement, respectively).

Conclusion

In the interpretation of HRCT findings of bronchiectasis, radiologist agreement appears to be fair. In our final analysis of the findings using the proposed score, we observed excellent interobserver and intraobserver agreement.