Noninfectious pulmonary complications after hematopoietic stem cell transplantation: practical approach to imaging diagnosis.

Hematopoietic stem cell transplantation (HSCT) is a widely available treatment for a variety of malignant and nonmalignant disorders. The treatment outcome is affected by the type of transplant and is limited by complications secondary to immunosuppression and treatment-related toxicity. Pulmonary complications are very common and follow a predictable timeline that reflects the immunologic status of the patient in the peritransplant period. Until recently, pulmonary complications were largely attributed to infectious causes. However, advances in diagnosis and treatment have led to a shift, and noninfectious complications have emerged as a major cause of morbidity and mortality in this population. With the increasing number of centers that perform HSCT, knowledge of posttransplant noninfectious pulmonary complications has become increasingly relevant. The basic principles of and indications for HSCT are described, and a timeline for the clinical, radiologic, and pathologic manifestations of noninfectious pulmonary complications is presented. Emphasis is given to high-resolution computed tomographic findings and the role of imaging in management of complications. A practical approach is provided to guide imaging interpretation and diagnosis of noninfectious pulmonary complications after HSCT.

Thoracic paracoccidioidomycosis: radiographic and CT findings.

Paracoccidioidomycosis (PCM) is the most common systemic mycosis in Latin America. Although most cases occur in developing countries, recent immigration patterns and an increase in travel have led to a growing number of PCM cases in the United States and Europe. PCM is caused by the dimorphic fungus Paracoccidioides brasiliensis, and the chronic form may progress to severe pulmonary involvement. Several radiologic patterns have been described for pulmonary PCM, including linear and reticular opacities, variable-sized nodules, patchy ill-defined opacities, airspace consolidation, and cavitary lesions. Fibrosis and paracicatricial emphysema are common associated findings. Chest computed tomography (CT) is the method of choice for evaluating pulmonary PCM, with the most common CT findings being ground-glass attenuation, consolidation, small or large nodules, masses, cavitations, interlobular septal thickening, emphysema, and fibrotic lesions. PCM is also an important cause of the "reversed halo" sign at high-resolution CT and should be considered in the differential diagnosis. Awareness of the multiple radiologic manifestations of PCM as well as its epidemiologic and clinical characteristics may permit early diagnosis and initiation of specific treatment, thereby reducing associated morbidity and mortality.

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.

Pulmonary paracoccidioidomycosis.

Paracoccidioidomycosis is a subacute or chronic systemic mycosis caused by Paracoccidioides brasiliensis, a soil saprophyte and thermally dimorphic fungus. The disease occurs mainly in rural workers in Latin America and is the most frequent endemic systemic mycosis in many countries of South America, where almost 10 million people are believed to be infected. Paracoccidioidomycosis should be regarded as a disease of travelers outside the endemic area. The primary pulmonary infection is subclinical in most cases, and individuals may remain infected throughout life without ever developing clinical signs. A small proportion of patients present with clinical disease. The lungs are frequently involved, and the pulmonary clinical manifestations must be differentiated from many other infectious and noninfectious conditions. Diagnosis should be based on epidemiological, clinical, and microbiological data. Effective treatment regimens are available to control the fungal infection, but most patients develop fibrotic sequelae that may severely hamper respiratory and adrenal function and the patient's well-being.

"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.

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.

Computed tomography findings in patients with tracheal paracoccidioidomycosis.

OBJECTIVE: To evaluate the high-resolution computed tomographic (CT) findings of patients with tracheal paracoccidioidomycosis. METHODS: The high-resolution CT scans of 178 patients with pulmonary paracoccidioidomycosis were reviewed, and 4 cases of proven tracheal involvement were studied. There were 3 male and 1 female patients, with ages ranging from 44 to 62 years (average, 49.2 years). The CT scans were retrospectively analyzed with special attention to the location of airway lesions, patterns of wall thickening, and occurrence of abnormal adjacent lymph nodes. Images were reviewed by 2 radiologists who reached decisions by consensus. RESULTS: The CT findings were circumferential parietal thickening (n = 4) and irregular (n = 3) or smooth (n = 1), with submucosal nodules (n = 2). Enlarged mediastinal lymph nodes were seen in 1 patient. CONCLUSIONS: The CT findings in patients with tracheal paracoccidioidomycosis were circumferential irregular thickening of the tracheal wall, with submucosal nodules.

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.

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.

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.

Angioinvasive pulmonary aspergillosis after allogeneic bone marrow transplantation: clinical and high-resolution computed tomography findings in 12 cases.

The aim of this study was to present the clinical and high-resolution CT scan findings of angioinvasive pulmonary aspergillosis (APA) in 12 patients who underwent allogeneic bone marrow transplantation (BMT). The CT scans were reviewed by three chest radiologists who assessed the pattern and distribution of findings by consent. There were 7 (58%) female and 5 (42%) male patients, with aging between 5 and 50 years (average of 26 years). All patients were submitted to BMT for the treatment of hematological conditions. The diagnosis of APA was defined between 5 and 373 days after BMT, with average of 111 days. Three cases (25%) were diagnosed in the neutropenic phase after the BMT, five (42%) in the early phase and four patients in the late phase post-BMT. Regarding high-resolution CT (HRCT) scan findings, nodules were found in 75% of the cases (9/12), most of the cases with more than 10 lesions (7/9) and of centrilobular localization (6/9). Consolidations were identified in seven patients (58%), being single in six, and commonly presenting ill defined borders (n=3) and subsegmental localization (n=5). Ground glass attenuation was found in six patients (50%). The halo sign was observed in nine cases (75%). Cavitations were seen in two air-space consolidations and one large nodule (2.5 cm). Patients submitted to BMT presenting respiratory symptoms and nodules or consolidations with halo sign at HRCT scan need to have the diagnosis of angioinvasive pulmonary aspergillosis included in all the post BMT phases.

[Acute pulmonary schistosomiasis: correlation between the high-resolution CT and pathological findings]. / Schistosomíase pulmonar aguda: Correlação entre a tomografia computadorizada de alta resolução e os achados anatomopatológicos.

A 35 years old rural worker presented with a 15 days history of progressive dyspnea, associated with dry cough, myalgia and fever. Few days before the symptoms, he had swim in a river. The chest radio- graphs demonstrated bilateral reticule-nodular infiltrates. The high-resolution CT showed patchy areas of ground-glass attenuation, irregular inter- lobular septal thickening, intralobular interstitial thickening, and small nodules, which are confluent in some regions. All the laboratory investigations were negative. The open lung biopsy shows parenchymal granulomatous inflammation, and numerous schistosome ova.

Conglomerated masses of silicosis in sandblasters: high-resolution CT findings.

The purpose of this study was to describe the high-resolution CT aspects of the silicosis and progressive massive fibrosis in sandblasters. The study was performed with 25 consecutive patients with silicosis and large opacities on chest radiography according to the International Labor Office (ILO) classification of pneumoconiosis. All patients presented with conglomerate masses involving the upper lobes, and in 92% of the cases the lesions were located in the posterior region of the lungs. The masses frequently showed nodular contour (76%), air bronchograms (76%), foci of calcification (72%), paracicatricial emphysema (72%), and adjacent pleural thickening (92%). Calcification of hilar or mediastinal lymph nodes (96%), mainly of the egg-shell type (56%), was also a common finding. In conclusion, in this specific group of patients, the sandblasters, the high-resolution CT demonstrated conglomerated masses with nodular contour, air bronchograms and foci of calcification, which were distributed mainly in the posterior region of the upper lobes. Calcification of hilar or mediastinal lymph nodes was also commonly seen.

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.

Herpes simplex virus type 2 pneumonia after bone marrow transplantation: high-resolution CT findings in 3 patients.

Bone marrow transplant recipients have increased prevalence of viral infections, including Herpes simplex pneumonia. The majority of infections are due to HSV type 1. We report the high-resolution CT findings in 3 bone marrow transplant patients with herpes simplex type 2 pneumonia. The most common CT features were focal areas of consolidation seen in 3 patients, and small centrilobular nodules and areas of ground-glass attenuation seen in 2 patients.

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.

Varicella pneumonia in immunocompetent adults: report of two cases, with emphasis on high-resolution computed tomography findings.

We report two cases of varicella pneumonia in immunocompetent patients, with emphasis on high-resolution computer tomography manifestations. The predominant findings consisted of multiple bilateral nodules, ranging from 1-10 mm in diameter, with or without a surrounding halo of ground-glass attenuation. Other findings include ground-glass opacities, focal areas of consolidation and small pleural effusions.

[Influenza B virus pneumonia after bone marrow transplantation: case report with emphasis to the high resolution computed tomography findings]. / Pneumonia pelo vírus influenza B pós-transplante de medula óssea: relato de caso com ênfase dos achados de tomografia computadorizada de alta resolução.

Nine year-old male patient, who underwent bone marrow transplantation because of acute myelogenous leukemia, presented with fever and dry cough three days after the procedure. The chest radiograph demonstrated bilateral diffuse reticular infiltrate. The high resolution computed tomography showed peribronchovascular interstitial thickening, peripheral small centrilobular nodules and areas of ground-glass attenuation. The bronchoalveolar lavage demonstrated positive direct fluorescence antibody testing against influenza B virus. Treatment with aerolizated ribavirin was instituted during 10 days and the patient showed clinical-radiological improvement.

Disseminated toxoplasmosis after bone marrow transplantation: high-resolution CT appearance.

A 16-year-old female patient, who had undergone bone marrow transplantation 35 days earlier, presented with dry cough, dyspnea, and fever for 4 days. Chest radiography showed poorly-defined bilateral opacities. High-resolution CT revealed bilateral ground glass opacities with superimposed septal thickening and intralobular linear opacities. Laboratory results were nonspecific and empiric treatment with multiple drugs was initiated. The patient had no response to therapy and died 12 days after the admission. At autopsy the patient had disseminated toxoplasmosis with involvement of the central nervous system, myocardium, bone marrow, and lungs.