Changes seen on computed tomography of the chest in mildly symptomatic adult patients with sickle cell disease

[Lung manifestations of sickle-cell disease]

Sickle-cell disease is an autosomal recessive genetic disorder of hemoglobin that causes systemic damage. Hypoxia is the main actor of sickle-cell disease. It initiates acutely the pathogenic cascade leading to tissue damages that in turn induce chronic hypoxia. Lung lesions represent the major risk of morbidity and mortality. Management of sickle-cell disease requires a tight collaboration between hematologists, intensivists and chest physicians. Recurrent episodes of thrombosis and hemolysis characterize the disease. New therapeutic protocols, associating hydroxyurea, transfusion program and stem cell transplantation in severe cases allow a prolonged survival until the fifth decade. However, recurrent pain, crisis, frequent hospital admissions due to infection, anemia or acute chest syndrome and chronic complications leading to organ deficiencies degrade the patients' quality of life. In low-income countries where the majority of sickle-cell patients are living, the disease is still associated with a high mortality in childhood. This paper focuses on acute chest syndrome and chronic lung manifestations.

Diaphragm ultrasonography in adults with sickle cell anemia: evaluation of morphological and functional aspects

OBJECTIVES

To assess morphological and functional aspects of the diaphragm by ultrasonography (US) in adults with sickle cell anemia (SCA) and evaluate if the diaphragmatic musculature can play a role in changes found in pulmonary function tests (PFTs) of these patients.

METHODS

This is a cross-sectional observational and single-center study involving 40 adults with SCA who underwent diaphragm US and PFTs with a maximum of 1 month between the two tests. Diaphragm US was performed in B and M modes, and echogenicity, thickness and movement of the muscle was assessed in different respiratory maneuvers.

RESULTS

Diaphragms had preserved echogenicity and the thickness was not significantly different between the groups. The SCA group exhibited significantly higher movement of the right hemidiaphragm during deep breathing (p = 0.004) and the sniff test (p = 0.0008) and lower movement of the left hemidiaphragm during quiet breathing (p = 0.009). There was a predominance of restrictive pattern (65%) and a global reduction in respiratory muscle strength (RMS) (70%).

CONCLUSIONS

This study shows that adults with SCA had normal morphostructural aspects and absence of diaphragm dysfunction. Otherwise, they presented greater movement of the right hemidiaphragm during deep breathing and sniff test maneuvers. Despite the restrictive pattern and the reduction in RMS found in PFTs, the diaphragm of young adults with SCA did not have weakness or paralysis.

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.

Relationship between ventilation heterogeneity and exercise intolerance in adults with sickle cell anemia

Sickle cell anemia (SCA) causes dysfunction of multiple organs, with pulmonary involvement as a major cause of mortality. Recently, there has been growing interest in the nitrogen single-breath washout (N₂SBW) test, which is able to detect ventilation heterogeneity and small airway disease when the results of other pulmonary function tests (PFTs) are still normal. Thus, the objectives of the present study were to assess the heterogeneity in the ventilation distribution in adults with SCA and to determine the association between the ventilation distribution and the clinical, cardiovascular, and radiological findings. This cross-sectional study included 38 adults with SCA who underwent PFTs, echocardiography, computed tomography (CT), and 6-min walk test. To evaluate the ventilation heterogeneity, the patients were categorized according to the phase III slope of the N₂SBW (SIII_N2). Compared with adults with lower SIII_N2 values, adults with higher SIII_N2 values showed lower hemoglobin levels (P=0.048), a history of acute chest syndrome (P=0.001), an elevated tricuspid regurgitation velocity (P=0.039), predominance of a reticular pattern in the CT (P=0.002), a shorter 6-min walking distance (6MWD) (P=0.002), and lower peripheral oxygen saturation (SpO₂) after exercise (P=0.03). SIII_N2 values correlated significantly with hemoglobin (r_s=-0.344; P=0.034), forced vital capacity (r_s=-0.671; P<0.0001), diffusing capacity for carbon monoxide (r_s=-0.376; P=0.019), 6MWD (r_s=-0.554; P=0.0003), and SpO₂ after exercise (P=0.040). Heterogeneity in the ventilation distribution is one of the most common pulmonary dysfunctions in adults with SCA. Moreover, relationships exist between ventilation heterogeneity, worsening of pulmonary structural damage, and reduced tolerance for exercise.

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.