OBJECTIVE: To evaluate the most significant features of parosteal osteosarcoma and to describe the most frequent findings on conventional radiology. MATERIALS AND METHODS: A retrospective study was performed including 26 cases of patients with parosteal osteosarcoma from the archives of "Clube do Osso", Rio de Janeiro, RJ, Brazil, with analysis of main clinical and radiological findings. RESULTS: The disease was prevalent in female patients in the third decade of life. Main clinical findings were the increase in volume on the site of the tumor (77% of cases) and local pain (68% of cases). The most frequent site of tumor was the popliteal fossa (40%), and metaphyseal involvement has occurred in 92% of cases. The most frequent radiological findings were densely mineralized lesions on juxtacortical locations, and irregularly thickened adjacent host cortex (92.3%), with adherence areas being observed in 88.5% of cases, besides lobular (50%) or irregular (38.5%) tumor margins. Also, a radiolucent line between the tumor and the adjacent bone (48%), a denser mineralization on the basis than in the periphery of the tumor (42.3%), and a small rate of periosteal reaction (15.4%) were found. CONCLUSION: Although computed tomography and magnetic resonance imaging are important modalities for identifying some aspects of parosteal osteosarcoma, conventional x-ray is essential in the initial evaluation of this type of lesion, most frequently allowing differential diagnosis with other surface bone lesions.

Keywords: Parosteal osteosarcoma, Bone radiology

OBJECTIVE: The present study was aimed at evaluating main radiological and epidemiological aspects of giant cell lesions (central giant cell granuloma and brown tumors of hyperparathyroidism). MATERIALS AND METHODS: The sample consisted of 26 giant cell lesions diagnosed in 22 patients divided into two groups, one of them including 17 patients who were not affected by hyperparathyroidism (group A) and another including five patients with such a disorder (group B). RESULTS: Prevalence was higher in female patients (72.7%). Most frequently, lesions occurred more in the second decade of life (mean age, 27 years). The mandible arc was most frequently involved (61.5%). Radiographically, 57.7% of lesions were multilocular and 42.3% were unilocular with defined limits. All of the 26 lesions caused expansion of bone, 15.4% radicular resorption, 50% dental displacement, and 11.5% produced pain. In the mandible 18.7% of the lesions crossed the midline. Group A showed 66.7% of lesions in the mandible and group B showed an even distribution of lesions between arches. In group A 66.7% of lesions were multilocular, and 33.3% unilocular; in group B 62.5% were unilocular, and 37.5% multilocular. CONCLUSION: Giant cells lesions may present themselves with a wide spectrum, from small, slow-growing unilocular lesions to extensive multilocular lesions. They present features of benignity, though some lesions may demonstrate a locally aggressive behavior.

Keywords: Central giant cell granuloma, Radiological aspects, Brown tumor, Hyperparathyroidism

OBJECTIVE: The present study was aimed at describing the findings on high-resolution computed tomography in patients with exogenous lipoid pneumonia secondary to mineral oil aspiration MATERIALS AND METHODS: Eight adult patients - four men and four women - with mean age of 69.4 years were studied. All of the patients were users of mineral oil for treating intestinal constipation. High-resolution computed tomography studies of these patients were blindly evaluated by two radiologists. RESULTS: Air-space consolidation with areas of fat density and crazy paving pattern were the most frequent findings. The lesions were bilateral in six cases and unilateral in two CONCLUSION: Air-space consolidation with areas of fat density, associated with a clinical history of mineral oil ingestion virtually indicates a diagnosis of exogenous lipoid pneumonia.

Keywords: Exogenous lipoid pneumonia, High-resolution computed tomography, HRCT, Aspiration pneumonia, Lungs

We report the findings of the high-resolution computed tomography of the chest of a patient with pulmonary talcosis related to intravenous injection of diluted oral medicine. The most important high-resolution computed tomography findings were small centrilobular nodules associated with conglomerated masses. Areas of emphysema and ground glass attenuation were also seen. These high-resolution computed tomography findings are highly suggestive of pulmonary talcosis.

Keywords: Talcosis, High-resolution computed tomography, Lung disease

We reviewed 17 cases of pulmonary lymphangioleiomyomatosis diagnosed by open lung biopsy. All patients were women with a mean age of 39.6 years. Tuberous sclerosis was diagnosed in two cases. The patients were submitted to high-resolution computed tomography that showed diffuse thin walled cystic lesions of less than 60 mm in diameter. Associated pneumothorax was seen in two cases. The main high-resolution computed tomography findings were diffuse, rounded, cystic lesions, generally of less than 20 mm in diameter.

Keywords: Lymphangioleiomyomatosis, Cystic lung diseases, High-resolution computed tomography

Pulmonary cryptococcosis is caused by Cryptococcus neoformans, a world-wide distribution unimorphic fungus that exhibits the same form in its natural habitat, animals and humans. The disease presents variable clinical and pathologic features and occurs in immunocompetent and immunocompromised patients. We reviewed the computed tomography findings of 14 patients with confirmed pulmonary cryptococcosis. The most frequent computed tomography findings were masses and pulmonary nodules. Other abnormalities included cavities, areas of consolidation, peribronchovascular interstitial thickening and diffuse linear opacities. Pulmonary masses were the most frequent findings (64.2%), followed by nodules (35.7%) whereas diffuse pulmonary disease accounted for 14.2% of the cases. The most affected areas were the upper lobes and the anterior regions. Computed tomography scan of the chest allows a precise assessment of pulmonary parenchymal involvement in patients with pulmonary cryptococcosis.

Keywords: Radiology, Pulmonary cryptococcosis, Computed tomography

Some technical aspects should be taken into consideration in order to guarantee the reliability of the assessment of pulmonary emphysema with lung computed tomography densitometry. Changes in lung density associated with variations in lungs inspiratory and expiratory levels, computed tomography slice thickness, reconstruction algorithm and type of computed tomography apparatus make tomographic comparisons more difficult in follow up studies of pulmonary emphysema. Nevertheless, quantitative computed tomography has replaced the visual assessment competing with pulmonary function tests as a sensitive method to measure pulmonary emphysema. The present review discusses technical variables of lung computed tomography and their influence on measurements of pulmonary emphysema.

Keywords: Accuracy; Measurement; Pulmonary emphysema; Computed tomography.