Dante Luiz Escuissato

Reversed Halo Sign: High-Resolution CT Scan Findings in 79 Patients

BACKGROUND The purpose of this study was to evaluate the high-resolution CT (HRCT) scan findings of patients with the reversed halo sign (RHS) and to identify distinguishing features among the various causes. METHODS Two chest radiologists reviewed the HRCT scans of 79 patients with RHS and determined the CT scan findings by consensus. We studied the morphologic characteristics, number of lesions, and presence of features associated with RHS. RESULTS Forty-one patients presented with infectious diseases (paracoccidioidomycosis, TB, zygomycosis, invasive pulmonary aspergillosis, Pneumocystis jiroveci pneumonia, histoplasmosis, cryptococcosis), and 38 presented with noninfectious diseases (cryptogenic organizing pneumonia, pulmonary embolism, sarcoidosis, edema, lepidic predominant adenocarcinoma [formerly bronchiolo-alveolar carcinoma], granulomatosis with polyangiitis [Wegener]). The RHS walls were smooth in 58 patients (73.4%) and nodular in 21 patients (26.6%). Lesions were multiple in 40 patients (50.6%) and single in 39 patients (49.4%). CONCLUSION The presence of nodular walls or nodules inside the halo of the RHS is highly suggestive of granulomatous diseases.

High-Resolution CT Findings of 77 Patients with Untreated Pulmonary Paracoccidioidomycosis

OBJECTIVE The objective of our study was to describe the high-resolution CT findings of 77 patients with pulmonary paracoccidioidomycosis (PCM) who had not yet been treated for PCM. MATERIALS AND METHODS The high-resolution CT scans of 77 consecutive patients with proven pulmonary PCM were reviewed by two chest radiologists, and decisions regarding the CT findings were reached by consensus. Seventy-one of the patients were men and six were women, with an average age of 49 years. The criteria for interpretation of the high-resolution CT scans are defined in the Fleischner Societys Glossary of Terms. RESULTS The most frequent high-resolution CT findings were ground-glass attenuation areas (58.4%), small centrilobular nodules (45.5%), cavitated nodules (42.9%), large nodules (41.6%), parenchymal bands (33.8%), areas of cicatricial emphysema (33.8%), interlobular septal thickening (31.2%), and architectural distortion (29.9%). Most of these high-resolution CT findings predominated at the periphery (53%) and posterior (88%) regions involving all lung zones, with discrete predominance in the middle zones (35%). CONCLUSION The high-resolution CT findings of patients with pulmonary PCM who have not yet been treated consist of ground-glass attenuation areas associated with small centrilobular nodules, cavitated nodules, large nodules, parenchymal bands, and areas of cicatricial emphysema. These abnormalities are usually distributed in the posterior and peripheral regions of the lungs, with discrete predominance in the middle lung zones.

Pulmonary invasive aspergillosis and candidiasis in immunocompromised patients: a comparative study of the high-resolution CT findings.

The purpose of this study was to compare the high-resolution computed tomography (HRCT) findings of pulmonary invasive aspergillosis and candidiasis in immunocompromised patients. The study included 54 immunocompromised patients (32 men, 22 women; 10 to 68 years of age, median 40 years) with a diagnosis of Aspergillus (n=32) or Candida (n=22) pulmonary infection obtained by sputum culture, bronchoalveolar lavage culture, transbronchial biopsy, surgical biopsy, or autopsy. High-resolution CT images were assessed for the presence and distribution of nodules, consolidation and ground-glass opacities. Presence of the CT halo sign and cavitation was also recorded and the overall distribution of abnormalities was assessed. Comparison was made using the Fisher exact test. Nodules were the most common finding, present in 84% (27 of 32) of patients with aspergillosis and 95% (21 of 22) of patients with candidiasis (P>0.3, Fisher exact test). Centrilobular nodules were more common in patients with aspergillosis (26 of 27, 96%) than in those with candidiasis (11 of 21, 52%) (P<0.001) and random nodules more common in candidiasis (10 of 21, 48%) than in aspergillosis (1 of 27, 4%) (P<0.001). Presence of the CT halo sign, cavitation, and ground-glass opacities was similar in both groups. In summary, pulmonary aspergillosis and candidiasis in immunocompromised patients manifest with similar high-resolution CT findings. Centrilobular nodules and consolidation are more common in aspergillosis. The presence of halo sign or cavitation is not helpful in the differential diagnosis.

Viral pneumonia after hematopoietic stem cell transplantation: high-resolution CT findings.

Hematopoietic stem cell transplantation (HSCT) is the treatment of choice for many hematologic malignancies and nonmalignant disorders of bone marrow function. Pulmonary infections from bacterial, fungal, and viral organisms are a major cause of morbidity and mortality in patients after HSCT. The radiographic and high-resolution computed tomography (HRCT) findings of the different lower respiratory tract viral infections are quite similar. Findings of viral pneumonia on HRCT include small poorly defined centrilobular nodules and patchy, often bilateral, areas of peribronchial ground-glass opacity and consolidation. Air trapping may be present because of associated bronchiolitis. Interlobular septal thickening, bronchial wall thickening, and tree-in-bud opacities may also be present. Advanced viral pneumonia with diffuse alveolar damage is characterized by patchy or confluent consolidation and ground-glass opacities. Although nonspecific, in the correct clinical setting, these HRCT findings can help suggest the diagnosis of viral pneumonia in recipients of HSCT.

Paracoccidioidomycosis: High-resolution computed tomography–pathologic correlation

OBJECTIVE The purpose of this study was to describe the high-resolution computed tomography (HRCT) features of pulmonary paracoccidioidomycosis and to correlate them with pathologic findings. METHODS The study included 23 adult patients with pulmonary paracoccidioidomycosis. All patients had undergone HRCT, and the images were retrospectively analyzed by two chest radiologists, who reached decisions by consensus. An experienced lung pathologist reviewed all pathological specimens. The HRCT findings were correlated with histopathologic data. RESULTS The predominant HRCT findings included areas of ground-glass opacities, nodules, interlobular septal thickening, airspace consolidation, cavitation, and fibrosis. The main pathological features consisted of alveolar and interlobular septal inflammatory infiltration, granulomas, alveolar exudate, cavitation secondary to necrosis, and fibrosis. CONCLUSION Paracoccidioidomycosis can present different tomography patterns, which can involve both the interstitium and the airspace. These abnormalities can be pathologically correlated with inflammatory infiltration, granulomatous reaction, and fibrosis.

Microlitíase alveolar pulmonar: achados na tomografia computadorizada de alta resolução do tórax em 10 pacientes

OBJECTIVE To present the high-resolution computed tomography (HRCT) findings of pulmonary alveolar microlithiasis. METHODS The HRCT scans of 10 adult patients (seven females and three males; mean age, 38.7 years) were retrospectively analyzed. The films were studied independently by two radiologists. RESULTS The most common tomographic findings were ground-glass attenuation and linear subpleural calcifications, which were seen in 90% of the patients. Other relevant findings were small parenchymal nodules, calcification along the interlobular septa, nodular cissures, subpleural nodules, subpleural cysts, dense consolidations, and a mosaic pattern of attenuation. CONCLUSIONS The HRCT findings presented by individuals with pulmonary alveolar microlithiasis are distinct. In most cases, such findings can form the basis of the diagnosis, eliminating the need to perform a lung biopsy.

Silicoproteinosis: High-Resolution CT Findings in 13 Patients

OBJECTIVE The purpose of this study was to evaluate the high-resolution CT findings of silicoproteinosis. CONCLUSION Silicoproteinosis usually manifests as bilateral consolidation in the posterior portions of the lungs and as numerous centrilobular nodules. Calcification within areas of consolidation is a common finding.

The Reversed Halo Sign on High-Resolution CT in Infectious and Noninfectious Pulmonary Diseases

OBJECTIVE The purpose of this article is to describe diseases that may present with the reversed halo sign on high-resolution CT. We emphasize the tomographic features most frequently associated with this sign and correlate them with histologic findings. CONCLUSION A wide spectrum of infectious and noninfectious diseases may present with the reversed halo sign on chest CT. The nonspecific nature of this sign should not cloud an otherwise fairly straightforward diagnosis, especially when associated background findings are typical. Although a rigorous analysis of associated CT findings may help with the differential diagnosis, histologic assessment is often needed for a definitive determination of the cause.

Unusual manifestations of metastatic pulmonary calcification: high-resolution CT and pathological findings.

The aim of this report is to describe the high-resolution CT and pathologic findings of 3 patients with unusual manifestations of metastatic pulmonary calcification. These include a case that presented with extensive dense consolidation, a case of metastatic calcification that improved spontaneously, and a case of metastatic calcification in a patient with no demonstrable biochemical abnormality or underlying disease. We conclude that metastatic calcification may present with dense bilateral consolidation, may improve spontaneously, and may rarely present in patients with no apparent underlying biochemical abnormality.

Acute pulmonary coccidioidomycosis: CT findings from 15 patients

The aim of this study was to describe the CT scan abnormalities in 15 patients with acute pulmonary coccidioidomycosis. Retrospective analysis of chest CT scans from 15 patients with acute pulmonary coccidioidomycosis was performed. The final diagnosis included the finding of Coccidioides immitis in mycology and/or histopathology, complemented by serology. Two radiologists evaluated the CT scans to study the type, size, profusion and localization of the findings. The final decisions were defined by consensus. CT scans showed multiple bilateral nodules in 13 patients and solitary nodules associated with consolidation in 2 cases. The nodules had ill-defined contours, ranging from 0.5 cm to 3.0 cm in diameter, which were predominant in the lower lobes in 11 cases. Cavitation of nodules was observed in 13 cases and coalescence in 7. Nodule-associated abnormalities were found in 13 cases, comprising interlobular septal thickening (n = 7) and consolidations (n = 6). Other abnormalities included lymph node enlargement (n = 6) and small pleural effusion (n = 2). In conclusion, the main CT finding in patients with acute coccidioidomycosis was that of multiple nodules (0.5-3.0 cm) at the lungs bases; a significant proportion of the remaining cases also showed other abnormalities. A diagnosis of coccidioidomycosis must be considered in patients with multiple lung nodules that are either in, or have recently been transported to, areas of endemic mycosis.