Pulmonary Involvement in Niemann-Pick Disease: A State-of-the-Art Review.

Niemann-Pick disease is a rare autosomal recessive lysosomal storage disease with three subtypes. Types A and B result from a deficiency of acid sphingomyelinase activity, associated with the accumulation of lipid-laden macrophages (so-called Niemann-Pick cells) in various tissues, especially the liver and spleen. Type A is a fatal neurodegenerative disorder of infancy. Type B Niemann-Pick disease is a less severe form with milder neurological involvement, characterized by hepatosplenomegaly, hyperlipidemia, and pulmonary involvement; most patients live into adulthood. Type C Niemann-Pick disease is a complex lipid storage disorder caused by defects in cholesterol trafficking, resulting in a clinical presentation dominated by neurological involvement. Pulmonary involvement occurs in all three types of Niemann-Pick disease, but most frequently in type B. Respiratory manifestations range from a lack of symptoms to respiratory failure. Progression of respiratory disease is slow, but inexorable, due to the accumulation of Niemann-Pick cells in the alveolar septa, bronchial walls, and pleura, potentially leading to a progressively worsening restrictive pattern on pulmonary function testing. Bronchoalveolar lavage has important diagnostic value because it shows the presence of characteristic Niemann-Pick cells. Radiographic findings consist of a reticular or reticulonodular pattern and, eventually, honeycombing, involving mainly the lower lung zones. The most common changes identified by high-resolution computed tomography are ground-glass opacities, mild smooth interlobular septal thickening, and intralobular lines. The aim of this review is to describe the main clinical, imaging, and pathological aspects of Niemann-Pick disease, with a focus on pulmonary involvement.

Tuberous Sclerosis Complex: State-of-the-Art Review with a Focus on Pulmonary Involvement.

Tuberous sclerosis complex (TSC) is an autosomal-dominant neurocutaneous disease with high phenotypic variability. The incidence is approximately one in 5000-10,000 births. TSC is characterized by widespread hamartomas and benign or rarely malignant neoplasms affecting various organs, most commonly the brain, skin, retinas, kidneys, heart, and lungs. The wide range of organs affected reflects the roles of TSC1 and TSC2 genes in the regulation of cell proliferation and differentiation. Clinical diagnostic criteria are important because genetic testing does not identify the mutation in up to 25% of patients. Imaging is pivotal, as it allows a presumptive diagnosis of TSC and definition of the extent of the disease. Common manifestations of TSC include cortical tubers, subependymal nodules, white matter abnormalities, retinal abnormalities, cardiac rhabdomyoma, lymphangioleiomyomatosis (LAM), renal angiomyolipoma, and skin lesions. Pulmonary involvement consists of LAM and, less commonly, multifocal micronodular pneumocyte hyperplasia (MMPH), which causes cystic and nodular diseases, respectively. Recent reports indicate that pulmonary LAM is found by computed tomography in up to 35% of the female patients with TSC. MMPH is rare and may be associated with LAM or, less frequently, occurs as an isolated pulmonary manifestation in women with TSC. Dyspnea and pneumothorax are common clinical presentations of LAM, whereas MMPH is usually asymptomatic. The aim of this review is to describe the main clinical, imaging, and pathological aspects of TSC, with a focus on pulmonary involvement.

High-resolution computed tomographic findings of cocaine-induced pulmonary disease: a state of the art review.

Cocaine is the most commonly used illicit drug among patients presenting at hospital emergency departments and the most frequent cause of drug-related deaths reported by medical examiners. Various respiratory problems temporally associated with cocaine use have been reported. Acute and chronic uses also are responsible for lung complications, such as pulmonary edema, alveolar hemorrhage, pulmonary hypertension, organizing pneumonia, emphysema, barotrauma, infection, cancer, eosinophilic disease, and aspiration pneumonia. Although most imaging findings are nonspecific, they may raise suspicion of a cocaine-related etiology when considered together with patients' profiles and medical histories. This literature review describes cocaine-induced diseases with pulmonary involvement, with an emphasis on high-resolution chest computed tomographic findings and patterns.

"Interstitial lung abnormalities": translation to and use in Portuguese.

Objective: To conduct a survey on the use of the term "interstitial lung abnormalities" in radiology reports in Brazil, propose an appropriate Portuguese-language translation for the term, and provide a brief review of the literature on the topic. Materials and Methods: A survey was sent via electronic message to various radiologists in Brazil, asking about their familiarity with the term, which translation of the term they use in Portuguese, and whether they use the criteria proposed by the Fleischner Society. Results: A total of 163 responses were received, from all regions of Brazil. Although the vast majority (88%) of the respondents stated that they were familiar with the term "interstitial lung abnormalities", there was considerable variation regarding the equivalent term they used in Portuguese. Conclusion: We suggest that the term "anormalidades pulmonares intersticiais" be used in order to standardize radiology reports and disseminate knowledge of these findings in Brazil.

Objetivo: Fazer um levantamento sobre o uso do termo interstitial lung abnormalities nos laudos radiológicos no Brasil, propor uma tradução para o termo e fazer uma breve revisão sobre o tema. Materiais e Métodos: Foi enviada uma pesquisa, por meio de mensagem eletrônica, para diversos radiologistas de todo o Brasil, questionando sobre a familiarização com o termo, qual tradução em português utilizam e se usam os critérios propostos pela diretriz da Sociedade Fleischner. Resultados: Foram recebidas 163 respostas de todas as regiões do Brasil e a grande maioria dos radiologistas respondeu estar familiarizado com o termo interstitial lung abnormalities (88%), mas houve grande variação em relação ao termo utilizado como tradução para o português. Conclusão: Sugerimos a padronização do termo "anormalidades pulmonares intersticiais", a fim de uniformizar os relatórios radiológicos e difundir esta entidade no País.

Concomitant COVID-19 and pulmonary tuberculosis: computed tomography aspects.

OBJECTIVE: To describe the relationship between coronavirus disease 2019 (COVID-19) and pulmonary tuberculosis during the current pandemic, as well as to describe the main computed tomography (CT) findings in patients suffering from both diseases simultaneously. MATERIALS AND METHODS: This was a retrospective, cross-sectional observational study of the chest CT scans of 360 patients with COVID-19, as confirmed by RT-PCR. RESULTS: In four (1.1%) of the patients, changes suggestive of COVID-19 and tuberculosis were observed on the initial CT scan of the chest. On chest CT scans performed for the follow-up of COVID-19, cavitary lesions with bronchogenic spread were observed in two of the four patients, whereas alterations consistent with the progression of fibrous scarring related to previous tuberculosis were observed in the two other patients. The diagnosis of tuberculosis was confirmed by the isolation of Mycobacterium tuberculosis. CONCLUSION: Albeit rare, concomitant COVID-19 and tuberculosis can be suggested on the basis of the CT aspects. Radiologists should be aware of this possibility, because initial studies indicate that mortality rates are higher in patients suffering from both diseases simultaneously.

OBJETIVO: Descrever a associação entre COVID-19 e tuberculose pulmonar durante a pandemia atual e descrever os principais achados tomográficos. MATERIAIS E MÉTODOS: Estudo retrospectivo transversal e observacional de tomografias computadorizadas de tórax realizadas em 360 pacientes com COVID-19 confirmada por RT-PCR. RESULTADOS: Em quatro pacientes (1,1%) foram encontradas alterações tomográficas sugestivas de associação entre COVID-19 e tuberculose. Em dois pacientes observaram-se escavações com disseminação broncogênica e em outros dois, alterações compatíveis com progressão de lesões fibrocicatriciais relacionadas a tuberculose prévia, em exames de controle para COVID-19. O diagnóstico foi confirmado pelo isolamento do Mycobacterium tuberculosis. CONCLUSÃO: Apesar de incomum, a associação entre COVID-19 e tuberculose pode ser sugerida com base em aspectos tomográficos, devendo os radiologistas estar atentos a esta possibilidade, pois estudos iniciais indicam aumento da mortalidade nesses pacientes.

Reversed halo sign in active pulmonary tuberculosis: criteria for differentiation from cryptogenic organizing pneumonia.

OBJECTIVE: The purpose of this study was to compare the morphologic characteristics of the "reversed halo" sign caused by tuberculosis with those caused by cryptogenic organizing pneumonia (COP) and to determine whether high-resolution CT (HRCT) can differentiate between these two conditions. MATERIALS AND METHODS: We retrospectively reviewed the HRCT scans of patients with the reversed halo sign caused by active tuberculosis and HRCT scans of patients with the reversed halo sign caused by COP. The study included 12 patients with active pulmonary tuberculosis (10 women and two men) and 10 patients with biopsy-proven COP (five women and five men). Tuberculosis was diagnosed by culture of sputum, bronchoalveolar lavage, or biopsy specimen. All patients underwent HRCT, and the images were reviewed by two chest radiologists who reached decisions by consensus. RESULTS: HRCT scans of all patients with active tuberculosis showed reversed halos with nodular walls; in most cases (10/12), we also observed nodules inside the halos. None of the HRCT scans of the COP cases reviewed had halos with nodular walls or nodules inside them. We also observed parenchymal abnormalities, such as consolidation, ground-glass, and linear opacities, associated with the reversed halo sign. Neither the number of reversed halo sign lesions nor the associated parenchymal lesions discriminated between tuberculosis and COP. Nevertheless, the association of the reversed halo sign with nodular walls or nodules inside the halo was seen only in tuberculosis patients. CONCLUSION: Although COP is considered the most frequent cause of the reversed halo sign, the presence of nodular walls or nodules inside the reversed halo strongly favors a diagnosis of active pulmonary tuberculosis rather than COP.

Lymphocytic interstitial pneumonia: computed tomography findings in 36 patients.

OBJECTIVE: To analyze the computed tomography (CT) findings of lymphocytic interstitial pneumonia (LIP). MATERIALS AND METHODS: We retrospectively reviewed the clinical and CT findings of 36 patients with LIP, including 25 women and 11 men, with a mean age of 52.5 years (age range, 22-78 years). RESULTS: The main associated diseases with LIP were Sjögren syndrome (42%), human immunodeficiency virus infection (17%), amyloidosis (17%), Sjögren syndrome associated with secondary amyloidosis (11%), idiopathic (8%), and systemic lupus erythematosus (5%). The predominant CT abnormalities were multiple cystic airspaces (n = 35), small nodules (n = 15), ground-glass opacities (n = 13), bronchiectasis and/or bronchiolectasis (n = 8), and thickening of the bronchovascular bundles (n = 8). Other CT findings included reticular opacities (n = 7), calcified nodules (n = 4), airspace consolidation (n = 4), emphysema (n = 3), honeycombing (n = 3), lymph node enlargement (n = 2), mosaic attenuation pattern (n = 1), and cavitated nodules (n = 1). CONCLUSION: The main CT findings of LIP were multiple cysts, small nodules, and ground-glass opacities.

OBJETIVO: Analisar os achados da tomografia computadorizada da pneumonia intersticial linfocítica. MATERIAIS E MÉTODOS: Trinta e seis pacientes com diagnóstico de pneumonia intersticial linfocítica (25 mulheres, 11 homens; faixa etária de 22 a 78 anos; idade média de 52,5 anos) tiveram os achados clínicos e tomográficos revisados retrospectivamente. RESULTADOS: As principais doenças associadas à pneumonia intersticial linfocítica foram síndrome de Sjögren (42%), infecção pelo HIV (17%), amiloidose (17%), síndrome de Sjögren associada a amiloidose secundária (11%), síndrome de Sjögren idiopática (8%) e lúpus eritematoso sistêmico (5%). As alterações predominantes na TC consistiram em múltiplos espaços aéreos císticos (n = 35), pequenos nódulos (n = 15), opacidades em vidro fosco (n = 13), bronquiectasias e bronquiolectasias (n = 8) e espessamento de feixes broncovasculares (n = 8). Outros achados da TC incluíram opacidades reticulares (n = 7), nódulos calcificados (n = 4), consolidação do espaço aéreo (n = 4), enfisema (n = 3), faveolamento (n = 3), linfonodomegalia linfática (n = 2), padrão de atenuação em mosaico (n = 1) e nódulos escavados (n = 1). CONCLUSÃO: Os principais achados tomográficos observados em pacientes com pneumonia intersticial linfocítica foram múltiplos cistos, pequenos nódulos e opacidades em vidro fosco.

Multimodal indirect imaging signs of pulmonary embolism.

The clinical diagnosis of pulmonary embolism is often difficult, as symptoms range from syncope and chest pain to shock and sudden death. Adding complexity to this picture, some patients with non-diagnosed pulmonary embolism may undergo unenhanced imaging examinations for a number of reasons, including the prevention of contrast medium-related nephrotoxicity, anaphylactic/anaphylactoid reactions and nephrogenic systemic fibrosis, as well as due to patients' refusal or lack of venous access. In this context, radiologists' awareness and recognition of indirect signs are cornerstones in the diagnosis of pulmonary embolism. This article describes the indirect signs of pulmonary embolism on chest X-ray, unenhanced CT, and MRI.

Incidence and morphological characteristics of the reversed halo sign in patients with acute pulmonary embolism and pulmonary infarction undergoing computed tomography angiography of the pulmonary arteries.

OBJECTIVE: To determine the incidence of the reversed halo sign (RHS) in patients with pulmonary infarction (PI) due to acute pulmonary embolism (PE), detected by computed tomography angiography (CTA) of the pulmonary arteries, and to describe the main morphological features of the RHS. METHODS: We evaluated 993 CTA scans, stratified by the risk of PE, performed between January of 2010 and December of 2014. Although PE was detected in 164 scans (16.5%), three of those scans were excluded because of respiratory motion artifacts. Of the remaining 161 scans, 75 (46.6%) showed lesions consistent with PI, totaling 86 lesions. Among those lesions, the RHS was seen in 33 (38.4%, in 29 patients). RESULTS: Among the 29 patients with scans showing lesions characteristic of PI with the RHS, 25 (86.2%) had a single lesion and 4 (13.8%) had two, totaling 33 lesions. In all cases, the RHS was in a subpleural location. To standardize the analysis, all images were interpreted in the axial plane. Among those 33 lesions, the RHS was in the right lower lobe in 17 (51.5%), in the left lower lobe in 10 (30.3%), in the lingula in 5 (15.2%), and in the right upper lobe in 1 (3.0%). Among those same 33 lesions, areas of low attenuation were seen in 29 (87.9%). The RHS was oval in 24 (72.7%) of the cases and round in 9 (27.3%). Pleural effusion was seen in 21 (72.4%) of the 29 patients with PI and the RHS. CONCLUSIONS: A diagnosis of PE should be considered when there are findings such as those described here, even in patients with nonspecific clinical symptoms.

"Interstitial lung abnormalities": translation to and use in Portuguese / Anormalidades pulmonares intersticiais: tradução e uso na língua portuguesa

Abstract Objective: To conduct a survey on the use of the term "interstitial lung abnormalities" in radiology reports in Brazil, propose an appropriate Portuguese-language translation for the term, and provide a brief review of the literature on the topic. Materials and Methods: A survey was sent via electronic message to various radiologists in Brazil, asking about their familiarity with the term, which translation of the term they use in Portuguese, and whether they use the criteria proposed by the Fleischner Society. Results: A total of 163 responses were received, from all regions of Brazil. Although the vast majority (88%) of the respondents stated that they were familiar with the term "interstitial lung abnormalities", there was considerable variation regarding the equivalent term they used in Portuguese. Conclusion: We suggest that the term "anormalidades pulmonares intersticiais" be used in order to standardize radiology reports and disseminate knowledge of these findings in Brazil.

Resumo Objetivo: Fazer um levantamento sobre o uso do termo interstitial lung abnormalities nos laudos radiológicos no Brasil, propor uma tradução para o termo e fazer uma breve revisão sobre o tema. Materiais e Métodos: Foi enviada uma pesquisa, por meio de mensagem eletrônica, para diversos radiologistas de todo o Brasil, questionando sobre a familiarização com o termo, qual tradução em português utilizam e se usam os critérios propostos pela diretriz da Sociedade Fleischner. Resultados: Foram recebidas 163 respostas de todas as regiões do Brasil e a grande maioria dos radiologistas respondeu estar familiarizado com o termo interstitial lung abnormalities (88%), mas houve grande variação em relação ao termo utilizado como tradução para o português. Conclusão: Sugerimos a padronização do termo "anormalidades pulmonares intersticiais", a fim de uniformizar os relatórios radiológicos e difundir esta entidade no País.

Concomitant COVID-19 and pulmonary tuberculosis: computed tomography aspects / Associação entre COVID-19 e tuberculose pulmonar: aspectos tomográficos

Abstract Objective: To describe the relationship between coronavirus disease 2019 (COVID-19) and pulmonary tuberculosis during the current pandemic, as well as to describe the main computed tomography (CT) findings in patients suffering from both diseases simultaneously. Materials and Methods: This was a retrospective, cross-sectional observational study of the chest CT scans of 360 patients with COVID-19, as confirmed by RT-PCR. Results: In four (1.1%) of the patients, changes suggestive of COVID-19 and tuberculosis were observed on the initial CT scan of the chest. On chest CT scans performed for the follow-up of COVID-19, cavitary lesions with bronchogenic spread were observed in two of the four patients, whereas alterations consistent with the progression of fibrous scarring related to previous tuberculosis were observed in the two other patients. The diagnosis of tuberculosis was confirmed by the isolation of Mycobacterium tuberculosis. Conclusion: Albeit rare, concomitant COVID-19 and tuberculosis can be suggested on the basis of the CT aspects. Radiologists should be aware of this possibility, because initial studies indicate that mortality rates are higher in patients suffering from both diseases simultaneously.

RESUMO Objetivo: Descrever a associação entre COVID-19 e tuberculose pulmonar durante a pandemia atual e descrever os principais achados tomográficos. Materiais e Métodos: Estudo retrospectivo transversal e observacional de tomografias computadorizadas de tórax realizadas em 360 pacientes com COVID-19 confirmada por RT-PCR. Resultados: Em quatro pacientes (1,1%) foram encontradas alterações tomográficas sugestivas de associação entre COVID-19 e tuberculose. Em dois pacientes observaram-se escavações com disseminação broncogênica e em outros dois, alterações compatíveis com progressão de lesões fibrocicatriciais relacionadas a tuberculose prévia, em exames de controle para COVID-19. O diagnóstico foi confirmado pelo isolamento do Mycobacterium tuberculosis. Conclusão: Apesar de incomum, a associação entre COVID-19 e tuberculose pode ser sugerida com base em aspectos tomográficos, devendo os radiologistas estar atentos a esta possibilidade, pois estudos iniciais indicam aumento da mortalidade nesses pacientes.

Niemann-Pick disease type B: HRCT assessment of pulmonary involvement.

OBJECTIVE: To analyze HRCT findings in patients with Niemann-Pick disease (NPD) type B, in order to determine the frequency of HRCT patterns and their distribution in the lung parenchyma, as well as the most common clinical characteristics. METHODS: We studied 13 patients (3 males and 10 females) aged 5 to 56 years. HRCT images were independently evaluated by two observers, and disagreements were resolved by consensus. The inclusion criteria were presence of abnormal HRCT findings and diagnosis of NPD type B confirmed by histopathological examination of a bone marrow, lung, or liver biopsy specimen. RESULTS: The most common clinical findings were hepatosplenomegaly and mild to moderate dyspnea. The most common HRCT patterns were smooth interlobular septal thickening and ground-glass opacities, which were both present in all patients. Intralobular lines were present in 12 patients (92.3%). A crazy-paving pattern was observed in 5 patients (38.4%), and areas of air trapping were identified in only 1 case (7.6%). Pulmonary involvement was bilateral in all cases, with the most affected area being the lower lung zone. CONCLUSIONS: Smooth interlobular septal thickening, with or without associated ground-glass opacities, in patients with hepatosplenomegaly is the most common finding in NPD type B.

Lymphocytic interstitial pneumonia: computed tomography findings in 36 patients / Pneumonia intersticial linfocítica: achados na tomografia computadorizada em 36 pacientes

Abstract Objective: To analyze the computed tomography (CT) findings of lymphocytic interstitial pneumonia (LIP). Materials and Methods: We retrospectively reviewed the clinical and CT findings of 36 patients with LIP, including 25 women and 11 men, with a mean age of 52.5 years (age range, 22-78 years). Results: The main associated diseases with LIP were Sjögren syndrome (42%), human immunodeficiency virus infection (17%), amyloidosis (17%), Sjögren syndrome associated with secondary amyloidosis (11%), idiopathic (8%), and systemic lupus erythematosus (5%). The predominant CT abnormalities were multiple cystic airspaces (n = 35), small nodules (n = 15), ground-glass opacities (n = 13), bronchiectasis and/or bronchiolectasis (n = 8), and thickening of the bronchovascular bundles (n = 8). Other CT findings included reticular opacities (n = 7), calcified nodules (n = 4), airspace consolidation (n = 4), emphysema (n = 3), honeycombing (n = 3), lymph node enlargement (n = 2), mosaic attenuation pattern (n = 1), and cavitated nodules (n = 1). Conclusion: The main CT findings of LIP were multiple cysts, small nodules, and ground-glass opacities.

Resumo Objetivo: Analisar os achados da tomografia computadorizada da pneumonia intersticial linfocítica. Materiais e Métodos: Trinta e seis pacientes com diagnóstico de pneumonia intersticial linfocítica (25 mulheres, 11 homens; faixa etária de 22 a 78 anos; idade média de 52,5 anos) tiveram os achados clínicos e tomográficos revisados retrospectivamente. Resultados: As principais doenças associadas à pneumonia intersticial linfocítica foram síndrome de Sjögren (42%), infecção pelo HIV (17%), amiloidose (17%), síndrome de Sjögren associada a amiloidose secundária (11%), síndrome de Sjögren idiopática (8%) e lúpus eritematoso sistêmico (5%). As alterações predominantes na TC consistiram em múltiplos espaços aéreos císticos (n = 35), pequenos nódulos (n = 15), opacidades em vidro fosco (n = 13), bronquiectasias e bronquiolectasias (n = 8) e espessamento de feixes broncovasculares (n = 8). Outros achados da TC incluíram opacidades reticulares (n = 7), nódulos calcificados (n = 4), consolidação do espaço aéreo (n = 4), enfisema (n = 3), faveolamento (n = 3), linfonodomegalia linfática (n = 2), padrão de atenuação em mosaico (n = 1) e nódulos escavados (n = 1). Conclusão: Os principais achados tomográficos observados em pacientes com pneumonia intersticial linfocítica foram múltiplos cistos, pequenos nódulos e opacidades em vidro fosco.

Cocaine-induced pulmonary changes: HRCT findings.

OBJECTIVE: To evaluate HRCT scans of the chest in 22 patients with cocaine-induced pulmonary disease. METHODS: We included patients between 19 and 52 years of age. The HRCT scans were evaluated by two radiologists independently, discordant results being resolved by consensus. The inclusion criterion was an HRCT scan showing abnormalities that were temporally related to cocaine use, with no other apparent causal factors. RESULTS: In 8 patients (36.4%), the clinical and tomographic findings were consistent with "crack lung", those cases being studied separately. The major HRCT findings in that subgroup of patients included ground-glass opacities, in 100% of the cases; consolidations, in 50%; and the halo sign, in 25%. In 12.5% of the cases, smooth septal thickening, paraseptal emphysema, centrilobular nodules, and the tree-in-bud pattern were identified. Among the remaining 14 patients (63.6%), barotrauma was identified in 3 cases, presenting as pneumomediastinum, pneumothorax, and hemopneumothorax, respectively. Talcosis, characterized as perihilar conglomerate masses, architectural distortion, and emphysema, was diagnosed in 3 patients. Other patterns were found less frequently: organizing pneumonia and bullous emphysema, in 2 patients each; and pulmonary infarction, septic embolism, eosinophilic pneumonia, and cardiogenic pulmonary edema, in 1 patient each. CONCLUSIONS: Pulmonary changes induced by cocaine use are varied and nonspecific. The diagnostic suspicion of cocaine-induced pulmonary disease depends, in most of the cases, on a careful drawing of correlations between clinical and radiological findings.

Organizing pneumonia: chest HRCT findings.

OBJECTIVE: To determine the frequency of HRCT findings and their distribution in the lung parenchyma of patients with organizing pneumonia. METHODS: This was a retrospective review of the HRCT scans of 36 adult patients (26 females and 10 males) with biopsy-proven organizing pneumonia. The patients were between 19 and 82 years of age (mean age, 56.2 years). The HRCT images were evaluated by two independent observers, discordant interpretations being resolved by consensus. RESULTS: The most common HRCT finding was that of ground-glass opacities, which were seen in 88.9% of the cases. The second most common finding was consolidation (in 83.3% of cases), followed by peribronchovascular opacities (in 52.8%), reticulation (in 38.9%), bronchiectasis (in 33.3%), interstitial nodules (in 27.8%), interlobular septal thickening (in 27.8%), perilobular pattern (in 22.2%), the reversed halo sign (in 16.7%), airspace nodules (in 11.1%), and the halo sign (in 8.3%). The lesions were predominantly bilateral, the middle and lower lung fields being the areas most commonly affected. CONCLUSIONS: Ground-glass opacities and consolidation were the most common findings, with a predominantly random distribution, although they were more common in the middle and lower thirds of the lungs.