Imaging Review of Normal and Abnormal Skeletal Maturation.

The growing skeleton undergoes well-described and predictable normal developmental changes, which may be misinterpreted a as pathologic condition at imaging. Primary and secondary ossification centers (SOCs), which form the diaphysis and the epiphysis of long bones, respectively, are formed by endochondral and intramembranous ossification processes. During skeletal maturation, the SOCs may appear irregular and fragmented, which should not be confused with fractures, osteochondritis dissecans, and osteochondrosis. These normal irregularities are generally symmetric with a smooth, round, and sclerotic appearance, which are aspects that help in the differentiation. The metaphysis, epiphysis, and growth plates or physes are common sites of injuries and normal variants in the pediatric skeleton. The metaphysis contains the newly formed bone from endochondral ossification and is highly vascularized. It is predisposed to easy spread of infections and bone tumors. The physis is the weakest structure of the immature skeleton. Injuries to this location may disrupt endochondral ossification and lead to growth disturbances. Pathologic conditions of the epiphyses may extend into the articular surface and lead to articular damage. At MRI, small and localized foci of bone marrow changes within the epiphysis and metaphysis are also a common finding. These can be related to residual red marrow (especially in the metaphysis of long bones and hindfoot), focal periphyseal edema (associated with the process of physeal closure), and ultimately to a normal ossification process. The authors review the imaging appearance of normal skeletal maturation and discuss common maturation disorders on the basis of developmental stage and location. ©RSNA, 2022.

Typical lesions in the fetal nervous system: correlations between fetal magnetic resonance imaging and obstetric ultrasonography findings.

Central nervous system (CNS) malformations play a role in all fetal malformations. Ultrasonography (US) is the best screening method for identifying fetal CNS malformations. A good echographic study depends on several factors, such as positioning, fetal mobility and growth, the volume of amniotic fluid, the position of the placenta, the maternal wall, the quality of the apparatus, and the sonographer's experience. Although US is the modality of choice for routine prenatal follow-up because of its low cost, wide availability, safety, good sensitivity, and real-time capability, magnetic resonance imaging (MRI) is promising for the morphological evaluation of fetuses that otherwise would not be appropriately evaluated using US. The aim of this article is to present correlations of fetal MRI findings with US findings for the major CNS malformations.

Cancerização de lóbulos: correlação de achados mamográficos e histológicos / Cancerization of lobules: correlation between mammography and histological findings

OBJETIVO: Caracterizar os aspectos mamográficos de cancerização de lóbulos associados a carcinoma ductal in situ (CDIS), por meio de correlação entre achados de imagem e histológicos. MATERIAIS E MÉTODOS: O presente estudo retrospectivo foi baseado em uma revisão de laudos histopatológicos de 135 pacientes submetidas a biópsia de mama. O diagnóstico de cancerização de lóbulos associada a CDIS foi confirmado em 12 das pacientes. Dois casos foram excluídos porque os cortes histopatológicos não estavam disponíveis para correlação da patologia com a mamografia. Todas as imagens mamográficas foram retrospectivamente analisadas às cegas quanto aos resultados histológicos e classificados por dois experientes radiologistas especializados em mama. RESULTADOS: Nove casos (90 por cento) apresentavam microcalcificações redondas agrupadas e um (10 por cento) apresentava calcificações lineares. A distribuição das calcificações foi definida como lobular em todos os casos. A análise histopatológica demonstrou quatro casos de CDIS cribriforme, dois casos de comedocarcinoma, um caso de CDIS sólido, um caso de CDIS cribriforme associado com sólido e um caso de CDIS cribriforme associado com sólido e comedocarcinoma. No caso em que havia calcificações redondas e lineares, o subtipo histológico era de CDIS cribriforme. Com relação ao número de microcalcificações, nove casos apresentavam mais do que 20 e apenas um caso apresentava menos do que 10 microcalcificações. CONCLUSÃO: Na presente coorte, a avaliação mamográfica de pacientes com CDIS apresentando cancerização de lóbulos demonstrou agrupamentos de microcalcificações redondas com distribuição lobular. Embora agrupamentos de calcificações redondas sejam normalmente associados a um processo benigno, a cancerização de lóbulos por CDIS pode produzir um padrão similar, mimetizando, assim, uma condição benigna.

OBJECTIVE: To characterize the mammographic appearance of cancerization of lobules by ductal carcinoma in situ (DCIS), by correlating imaging and histological findings. MATERIALS AND METHODS: This retrospective study was based on a review of the histopathological reports of 135 patients who underwent breast biopsy. A diagnosis of cancerization of lobules by DCIS was confirmed in 12 patients. Two cases were excluded because the histopathological sections were not available to correlate pathological and mammographic findings. All mammograms were retrospectively reviewed and categorized by two experienced breast radiologists, with no knowledge of the histological findings. RESULTS: Nine cases (90 percent) presented clusters of round microcalcifications, and one (10 percent) had round and linear calcifications. The distribution of the calcifications was defined as lobular in all the cases. Histopathological study showed four cases of cribriform DCIS, two cases of comedo DCIS, one case of solid DCIS, one case of cribriform associated with solid DCIS, and one case of cribriform associated with solid and comedo DCIS. In the case showing round and linear calcifications, the histological subtype was cribriform DCIS. With respect to the number of microcalcifications, nine cases presented more than 20, and only one case showed less than 10 microcalcifications. CONCLUSION: In our cohort, the mammographic evaluation of patients with DCIS presenting cancerization of lobules demonstrated clusters of microcalcifications in a lobular distribution. Although clusters of round calcifications are typically associated with a benign process, cancerization of lobules by DCIS may produce a similar pattern, thus mimicking a benign condition.

Clinical and imaging manifestations of hemorrhagic pulmonary leptospirosis: a state-of-the-art review.

Leptospirosis, a spirochetal zoonosis, is frequently unrecognized due to its manifestation as an undifferentiated fever. It is an emerging infectious disease that has changed from an occupational disease of veterinarians, farmers, butchers, and other animal handlers to a cause of epidemics in poor and decayed urban communities in developing countries. Humans are infected when mucous membranes or abraded skin come into direct contact with the urine of infected animals, especially rats and dogs. Mortality from severe leptospirosis is high, even when optimal treatment is provided. The diagnosis of leptospirosis is based on clinical findings, history of direct or indirect exposure to infected animals in endemic areas, and positive serological tests. It should be considered in the differential diagnosis of patients with febrile illnesses associated with pneumonitis and respiratory failure, especially when hemoptysis is present. Severe pulmonary involvement in leptospirosis consists primarily of hemorrhagic pneumonitis. In advanced cases, adult respiratory distress syndrome and massive pulmonary hemorrhage may occur. Chest radiographs show bilateral alveolar infiltrates and/or resemble viral pneumonia, bronchopneumonia, tuberculosis, adult respiratory distress syndrome, and other causes of pulmonary hemorrhage such as Goodpasture syndrome. High-resolution computed tomography scans may show nodular infiltrates, areas of consolidation, ground-glass attenuation, and crazy-paving patterns. Bronchoalveolar lavage and autopsy studies have suggested that ground-glass opacities and air-space consolidations are secondary to pulmonary hemorrhage. Although not specific, the presence of these computed tomography findings in a febrile patient with an appropriate history should suggest a diagnosis of leptospirosis.

Congenital chest malformations: a multimodality approach with emphasis on fetal MR imaging.

Congenital chest malformations can range from small and asymptomatic entities to large space-occupying masses that require immediate surgical treatment. They may affect the foregut, pulmonary airway, and vasculature. Hybrid conditions are commonly seen, with interrelated chest malformations having various radiologic and pathologic features. An understanding of the in utero complications associated with fetal chest masses is essential for appropriate monitoring during pregnancy, treatment recommendations, and delivery management. Technologic advances have greatly improved the diagnosis of fetal anomalies. Congenital chest malformations are usually evaluated in the prenatal period with fetal sonography, but fetal magnetic resonance (MR) imaging is a well-established modality that is used as an adjunct technique in difficult diagnostic situations. MR imaging can provide excellent tissue contrast with more accurate analysis of the fetal anatomy and superior differentiation between the abnormalitites and adjacent structures, thereby allowing early planning of prenatal management.

Primary tracheal non-Hodgkin lymphoma: case report with an emphasis on computed tomography findings.

A 24-year-old male presented with productive cough associated with fever, dyspnea, and hoarseness. A chest radiograph showed nonhomogeneous air-space consolidations, mainly in the middle and inferior zones of both lungs, with cavitations and peribronchial thickening. The computed tomography scan demonstrated irregular, lobulated narrowing of the trachea, and parenchymal consolidations containing air bronchogram, peribronchial thickening, and cavitations. Afterward, the patient was referred for a bronchoscopy with a biopsy of the tracheal mucosa. The samples were submitted to immunohistochemical analysis and revealed a diagnosis of diffuse large B-cell non-Hodgkin lymphoma of the trachea. A culture of bronchoalveolar lavage fluid revealed Pseudomonas aeruginosa. Antibiotic treatment was proposed as a first treatment. The patient did not receive intensive chemotherapy because of his comorbid conditions and died 2 months later.

Pulmonary talcosis: imaging findings.

Talc is a mineral widely used in the ceramic, paper, plastics, rubber, paint, and cosmetic industries. Four distinct forms of pulmonary disease caused by talc have been defined. Three of them (talcosilicosis, talcoasbestosis, and pure talcosis) are associated with aspiration and differ in the composition of the inhaled substance. The fourth form, a result of intravenous administration of talc, is seen in drug users who inject medications intended for oral use. The disease most commonly affects men, with a mean age in the fourth decade of life. Presentation of patients with talc granulomatosis can range from asymptomatic to fulminant disease. Symptomatic patients typically present with nonspecific complaints, including progressive exertional dyspnea, and cough. Late complications include chronic respiratory failure, emphysema, pulmonary arterial hypertension, and cor pulmonale. History of occupational exposure or of drug addiction is the major clue to the diagnosis. The high-resolution computed tomography (HRCT) finding of small centrilobular nodules associated with heterogeneous conglomerate masses containing high-density amorphous areas, with or without panlobular emphysema in the lower lobes, is highly suggestive of pulmonary talcosis. The characteristic histopathologic feature in talc pneumoconiosis is the striking appearance of birefringent, needle-shaped particles of talc seen within the giant cells and in the areas of pulmonary fibrosis with the use of polarized light. In conclusion, computed tomography can play an important role in the diagnosis of pulmonary talcosis, since suggestive patterns may be observed. The presence of these patterns in drug abusers or in patients with an occupational history of exposure to talc is highly suggestive of pulmonary talcosis.

Pulmonary involvement in Kaposi sarcoma: correlation between imaging and pathology.

Kaposi sarcoma is a low-grade mesenchymal tumor involving blood and lymphatic vessels. There are four variants of this disease, each presenting a different clinical manifestation: classic or sporadic, African or endemic, organ transplant-related or iatrogenic, and AIDS-related or epidemic. Kaposi sarcoma is the most common tumor among patients with HIV infection, occurring predominantly in homosexual or bisexual men. The pulmonary involvement in Kaposi sarcoma occurs commonly in critically immunosupressed patients who commonly have had preceding mucocutaneous or digestive involvement.The etiology of Kaposi sarcoma is not precisely established; genetic, hormonal, and immune factors, as well as infectious agents, have all been implicated. There is evidence from epidemiologic, serologic, and molecular studies that Kaposi sarcoma is associated with human herpes virus type 8 infection. The disease starts as a reactive polyclonal angioproliferative response towards this virus, in which polyclonal cells change to form oligoclonal cell populations that expand and undergo malignant transformation.The diagnosis of pulmonary involvement in Kaposi sarcoma usually can be made by a combination of clinical, radiographic, and laboratory findings, together with the results of bronchoscopy and transbronchial biopsy. Chest high-resolution computed tomography scans commonly reveal peribronchovascular and interlobular septal thickening, bilateral and symmetric ill-defined nodules in a peribronchovascular distribution, fissural nodularity, mediastinal adenopathies, and pleural effusions. Correlation between the high-resolution computed tomography findings and the pathology revealed by histopathological analysis demonstrate that the areas of central peribronchovascular infiltration represent tumor growth involving the bronchovascular bundles, with nodules corresponding to proliferations of neoplastic cells into the pulmonary parenchyma. The interlobular septal thickening may represent edema or tumor infiltration, and areas of ground-glass attenuation correspond to edema and the filling of air spaces with blood. These findings are a result of the propensity of Kaposi sarcoma to grow in the peribronchial and perivascular axial interstitial spaces, often as continuous sheets of tumor tissue.In conclusion, radiological findings can play a major role in the diagnosis of pulmonary Kaposi sarcoma since characteristic patterns may be observed. The presence of these patterns in patients with AIDS is highly suggestive of Kaposi sarcoma.

Bacterial pneumonia following bone marrow transplantation: HRCT findings.

OBJECTIVE: To describe HRCT findings in patients with bacterial pneumonia following bone marrow transplantation (BMT). METHODS: This was a retrospective study involving 30 patients diagnosed with bacterial pneumonia in whom HRCT of the chest was performed within 24 h after the onset of symptoms and the diagnosis was confirmed, based on a positive culture of sputum or bronchial aspirate, together with a positive pleural fluid or blood culture, within one week after symptom onset. There were 20 male patients and 10 female patients. The median age was 21 years (range, 1-41 years). The BMT had been performed for the treatment of the following: chronic myeloid leukemia, in 14 cases; severe aplastic anemia, in 6; acute myeloid leukemia, in 4; Fanconi's anemia, in 3; and acute lymphocytic leukemia, in 3. Two radiologists analyzed the HRCT scans and reached their final decisions by consensus. RESULTS: The most common HRCT findings were air-space consolidation (in 60%), small centrilobular nodules (in 50%), ground-glass opacities (in 40%), bronchial wall thickening (in 20%), large nodules (in 20%), pleural lesions (in 16.7%) and tree-in-bud opacities (in 10%). The pulmonary lesions were distributed in the central and peripheral areas in 15 patients, whereas they were exclusively peripheral in 11. Lesions were located in the lower and middle lobes of the lung in 22 and 20 patients, respectively. CONCLUSIONS: The most common HRCT findings in our patient sample were air-space consolidation, small centrilobular nodules and ground-glass opacities, most often in the central and peripheral regions of the middle and lower lung zones.

Bacterial pneumonia following bone marrow transplantation: HRCT findings / Achados de TCAR nas pneumonias bacterianas após transplante de medula óssea

Objective: To describe HRCT findings in patients with bacterial pneumonia following bone marrow transplantation(BMT). Methods: This was a retrospective study involving 30 patients diagnosed with bacterial pneumonia in whom HRCT of the chest was performed within 24 h after the onset of symptoms and the diagnosis was confirmed, based on a positive culture of sputum or bronchial aspirate, together with a positive pleural fluid or blood culture, within one week after symptom onset. There were 20 male patients and 10 female patients. The median age was 21 years (range, 1-41 years). The BMT had been performed for the treatment of the following: chronic myeloid leukemia, in 14 cases; severe aplastic anemia, in 6; acute myeloid leukemia, in 4; Fanconi’s anemia, in 3; and acute lymphocytic leukemia, in 3. Two radiologists analyzed the HRCT scans and reached their final decisions by consensus. Results: The most common HRCT findings were air-space consolidation (in 60%), small centrilobular nodules (in 50%), ground-glass opacities (in 40%), bronchial wall thickening (in 20%), large nodules (in 20%), pleural lesions (in 16.7%) and tree-in-bud opacities (in 10%). The pulmonary lesions were distributed in the central and peripheral areas in 15 patients, whereas they were exclusively peripheral in 11. Lesions were locatedin the lower and middle lobes of the lung in 22 and 20 patients, respectively. Conclusions: The most common HRCT findings in our patient sample were air-space consolidation, small centrilobular nodules and ground-glass opacities, most often in the central and peripheral regions of the middle and lower lung zones.

Objetivo: Descrever os achados de TCAR em pacientes com pneumonia bacteriana após transplante de medulaóssea (TMO). Métodos: Estudo retrospectivo com 30 pacientes diagnosticados com pneumonia bacteriana, documentada com TCAR do tórax realizada em até 24 h do início dos sintomas, e com diagnóstico comprovado com base em cultura positiva de escarro ou de aspirado brônquico associada à cultura positiva de líquido pleural ou de sangue dentro de uma semana após o início dos sintomas. Foram avaliados 20 pacientes masculinos e 10 femininos, com mediana de idade de 21 anos (variação, 1-41 anos). O TMO foi realizado para o tratamento de leucemia mieloide crônica (n = 14), anemia aplástica severa (n = 6), leucemia mieloide aguda (n = 4), anemia de Fanconi (n = 3) e leucemia linfoide aguda (n = 3). Dois radiologistas analisaram os exames de TCAR, chegando a decisões finais por consenso. Resultados: Os achados de TCAR mais frequentes foram consolidação do espaço aéreo (60%),pequenos nódulos centrolobulares (50%), opacidade em vidro fosco (40%), espessamento de parede brônquica (20%), nódulos grandes (20%), lesões pleurais (16,7%) e opacidades em padrão de árvore em brotamento (10%). As alterações pulmonares estavam distribuídas nas regiões centrais e periféricas dos pulmões em 15 pacientes e somente na periferia em 11 pacientes. As lesões estavam localizadas no terço inferior e no terço médio dos pulmões em 22 e 20 pacientes, respectivamente. Conclusões: Os achados de TCAR mais comuns na nossa amostra foram consolidações do espaço aéreo, pequenos nódulos centrolobulares e opacidades em vidro-fosco, distribuídos nas regiões centrais e periféricas dos terços médio e inferior dos pulmões.

"Crazy-paving" patterns on high-resolution CT scans in patients with pulmonary complications after hematopoietic stem cell transplantation.

OBJECTIVE: To describe the pulmonary complications following hematopoietic stem cell transplantation (HSCT) that can present with a "crazy-paving" pattern in high-resolution CT scans. MATERIALS AND METHODS: Retrospective review of medical records from 2,537 patients who underwent HSCT. The "crazy-paving" pattern consists of interlobular and intralobular septal thickening superimposed on an area of ground-glass attenuation on high-resolution CT scans. The CT scans were retrospectively reviewed by two radiologists, who reached final decisions by consensus. RESULTS: We identified 10 cases (2.02%), seven male and three female, with pulmonary complications following HSCT that presented with the "crazy-paving" pattern. Seven (70%) patients had infectious pneumonia (adenovirus, herpes simplex, influenza virus, cytomegalovirus, respiratory syncytial virus, and toxoplasmosis), and three patients presented with non-infectious complications (idiopathic pneumonia syndrome and acute pulmonary edema). The "crazy-paving" pattern was bilateral in all cases, with diffuse distribution in nine patients (90%), predominantly in the middle and inferior lung regions in seven patients (70%), and involving the anterior and posterior regions of the lungs in nine patients (90%). CONCLUSION: The "crazy-paving" pattern is rare in HSCT recipients with pulmonary complications and is associated with infectious complications more commonly than non-infectious conditions.

Leptospirosis of the lung presenting with crazy-paving pattern: correlation between the high-resolution CT and pathological findings.

The authors present the high-resolution CT findings of a patient with diffuse pulmonary hemorrhage due to leptospirosis. The main finding consisted of extensive ground-glass opacities super imposed on mild interlobular septal thickening, resulting in the appearance termed "crazy- paving". The patient died and the necropsy showed extensive haemorrhage filling the airspace and blood infiltrating the interlobular sep- ta. The correlation between the high-resolution CT and pathological findings is emphasised.

Idiopathic pneumonia syndrome after bone marrow transplantation presenting with "crazy-paving" pattern on high-resolution computed tomography: a case report.

The authors present the high-resolution computed tomography findings of a patient with idiopathic pneumonia syndrome after bone marrow transplantation. The main finding consisted of extensive ground-glass opacities superimposed to mild interlobular septal thickening, resulting in the appearance termed "crazy-paving". Following the clinical, laboratorial and imaging criteria, the diagnosis of idiopathic pulmonary syndrome was defined and corticosteroids were introduced. The clinical symptoms improved in the following days, and the patient was discharged from the hospital.

Neurofibromatosis type 1 with tracheobronchial neurofibromas: case report with emphasis on tomographic findings.

A 65-year-old man with neurofibromatosis type 1 (NF-1) presented with a 3-month history of dyspnea and cough. The chest spiral computed tomography scan showed multiple neurofibromas in the larynx and tracheobronchial tree. Bronchoscopy was performed and the biopsy confirmed the diagnosis of benign neurofibroma. The upper airway involvement in NF-1 is rare, and the diagnosis on the basis of the clinical manifestation may be difficult. The clinical manifestations of patients with tracheobronchial neurofibromas are mostly related to airway obstruction, presenting with cough, wheezing, and dyspnea. Our case illustrates the value of spiral computed tomography imaging in providing an excellent anatomic definition of this rare manifestation of NF.

AIDS-related Kaposi sarcoma of the lung presenting with a "crazy-paving" pattern on high-resolution CT: imaging and pathologic findings.

Kaposi sarcoma (KS) is a fulminate and disseminated form of acquired immunodeficiency syndrome (AIDS)-defining neoplasm, usually presenting pulmonary involvement. We report a 40-year-old woman with AIDS and biopsy-proven KS showing unusual high-resolution computed tomography (HRCT) findings. HRCT showed areas of ground-glass attenuation with superimposed septal thickening ("crazy-paving" pattern). CT-pathologic correlation revealed that crazy-paving pattern in this case was due to accompanying pulmonary edema and hemorrhage in addition to tumor cell infiltration into the peribronchovascular interstitium, interlobular and alveolar septa. The authors suggest the inclusion of KS in the differential diagnosis of lung diseases in patients with AIDS presenting with crazy-paving pattern on the HRCT.

Pulmonary infections following bone marrow transplantation: high-resolution CT findings in 35 paediatric patients.

PURPOSE: The purpose of this study was to assess the high-resolution CT findings of paediatric patients who had pulmonary infections following bone marrow transplantation (BMT), and to evaluate the differential diagnosis through high-resolution CT of the various pathogens responsible for pulmonary infections after BMT. PATIENTS AND METHODS: The study included 35 consecutive patients who had documented pulmonary infection, high-resolution CT of the chest performed within 24h of the beginning of symptoms, and proven diagnosis within 1 week of the onset of symptoms. The pulmonary infections were due to viruses (n=16), bacteria (n=9), fungi (n=9), and protozoa (n=1). Two radiologists analyzed the CT scans and reached final decisions regarding the findings by consensus. RESULTS: Four patients with confirmed pneumonia had normal high-resolution CT scans. Regarding the viral infections, the most frequent features were areas of ground-glass attenuation (43.7%) and small centrilobular nodules (31.2%). Airspace consolidation (88.9%), small centrilobular nodules (22.2%) and ground-glass attenuation (22.2%) were the most frequent findings in patients with bacterial pneumonia following BMT. Large nodules were seen in 66.7% of the patients with fungal pneumonia, and in only one case of virus infection. The "halo sign" (n=5) was seen only in patients with fungal pneumonia. CONCLUSION: In conclusion, the main causes of pulmonary infection in paediatric patients following BMT share similar high-resolution CT findings. Large nodules and "halo sign" are more common in patients with fungal infections.

Consolidation with diffuse or focal high attenuation: computed tomography findings.

This pictorial essay aims to present various lesions that could present as consolidations with diffuse of focal high attenuation on computed tomography, helping to make the diagnosis more confident and specific. The radiologic literature has limited information about such findings and the role of computed tomography in the differential diagnosis. The following diseases are presented: metastatic pulmonary calcification, pulmonary alveolar microlithiasis, amiodarone lung, talcosis, iodinated oil embolism, tuberculosis, silicoproteinosis, and amyloidosis. In conclusion, air-space consolidations can be seen in a wide variety of diseases affecting the lungs. The identification of the different patterns of consolidation with focal high attenuation narrows the differential diagnosis. We present a diagnostic approach based on appearance and distribution of these lesions.

Lipoid pneumonia in children following aspiration of mineral oil used in the treatment of constipation: high-resolution CT findings in 17 patients.

BACKGROUND: Exogenous lipoid pneumonia is a rare disorder caused by aspiration of mineral, vegetable and animal oils. High-resolution CT findings of lipoid pneumonia in children taking mineral oil for constipation have been rarely reported. OBJECTIVE: To evaluate the high-resolution CT findings in 17 children with exogenous lipoid pneumonia following aspiration of mineral oil. MATERIALS AND METHODS: The study included nine boys and eight girls, with ages ranging from 2 months to 9 years. All patients underwent high-resolution CT and the images were reviewed by two radiologists who reached decisions by consensus. The inclusion criteria were an abnormal radiograph, history of taking mineral oil and the presence of intrapulmonary lipids proved by bronchoalveolar lavage or open lung biopsy. RESULTS: The most common symptoms were cough (n = 13), mild fever (n = 11), and progressive dyspnea (n = 9). The main CT findings were air-space consolidations (100%), usually with areas of fatty attenuation (70.6%), areas of ground-glass attenuation (52.9%), and a crazy-paving pattern (17.6%), predominating bilaterally in the posterior and lower regions of the lungs. CONCLUSION: The high-resolution CT features in children with exogenous lipoid pneumonia are air-space consolidations and ground-glass attenuation, occasionally with a crazy-paving pattern, distributed bilaterally in the posterior and lower zones of the lungs.