Ana Giménez

Infectious pulmonary nodules in immunocompromised patients: usefulness of computed tomography in predicting their etiology.

Purpose To review the high-resolution computed tomography (CT) findings in immunocompromised patients who had nodular opacities and a proven diagnosis to determine whether the various infectious pulmonary nodules have distinguishing features on CT. Materials and Methods The high-resolution CT scans obtained in 78 immunocompromised patients with solitary or multiple nodular opacities of proven infectious etiology were reviewed retrospectively by 2 independent thoracic radiologists. Patients whose predominant abnormality consisted of branching linear or nodular opacities (tree-in-bud pattern) characteristic of infectious bronchiolitis and endobronchial spread of tuberculosis were excluded. The CT scans were assessed for the presence, appearance, size, and distribution of parenchymal nodules. Relations between findings at CT and the different infectious etiologies of nodules were assessed with regression analysis. Agreement between the 2 observers was assessed using the &kgr; statistic. Results The infectious causes included mycobacteria (n = 24), fungi (n = 22), bacteria (n = 20), and viruses (n = 12). Multivariate analysis demonstrated that a diameter <10 mm was the only independent predictor of etiology (P < 0.0001) and that patients whose nodules all measured less than 10 mm in diameter were most likely to have a viral infection. Nodules limited in size to less than 10 mm in diameter were seen in 83% of viral infections compared with 5% of bacterial infections (odds ratio [OR] = 95.0; 95% confidence interval (CI): 6.08–4,321.5, P < 0.0001), 0% of mycobacterial infections (OR = 91.7; 95% CI: 7.21–4,090.22, P < 0.0001), and 14% of fungal infections (OR = 31.67; 95% CI: 3.56–375.09, P = 0.0003). Conclusion Although some overlap exists, nodule size is helpful in the differential diagnosis of infectious causes of nodules in immunocompromised patients. Patients whose nodules are all less than 10 mm in diameter are most likely to have a viral infection.

Air trapping in primary Sjögren syndrome : Correlation of expiratory CT with pulmonary function tests

PURPOSE The purpose of our study was to correlate the extent of air trapping on expiratory CT scans with results of pulmonary function tests (PFTs) in a large group of patients with primary Sjögren syndrome and to determine whether these techniques may be complementary in assessing small airways obstruction. METHOD Thirty-four nonsmoking patients with proven primary Sjögren syndrome and 10 healthy nonsmokers underwent paired inspiratory-expiratory thin section CT and PFTs. Expiratory scans were scored for the presence and extent of areas of air trapping. Extent of air trapping was assessed visually and given a score. The functional significance of the extent of air trapping was evaluated in both groups and then correlated with the results of PFTs. RESULTS Bronchiolar abnormalities were seen in 11 (32%) of 34 patients with primary Sjögren syndrome. On the expiratory CT scans, a mosaic pattern of lung attenuation was identified in 17 patients. Air trapping was found in 44 of 204 lobar observations on the expiratory scans. The median point scale score at end-expiration was 3.6 (20%, Grade 1), ranging from 1 (5.5%, Grade 1) to 9 (50%, Grade 2). The mean total score of air trapping was more prevalent in lower (46/68) lobes (22.4%) than in upper (22/136) lobes (5.3%) (p < 0.001). PFTs were normal in the primary Sjögren syndrome patients as well as the healthy subjects. Air trapping was found more frequently in patients with primary Sjögren syndrome than in the healthy group. Only during exhalation was there evidence of minimal lobular-sized areas or air trapping (Grade 1) in three of the healthy subjects. We did not find any correlation between air trapping and PFTs including the forced expiratory flow rate between 25 and 75% of the forced vital capacity (FEF25-75). CONCLUSION Expiratory high resolution CT revealed the extent of bronchiolar disease in patients with primary Sjögren syndrome. We also found that the extent of air trapping did not correlate with PFTs, which suggests the existence of a subclinical bronchiolar inflammatory process that may precede detectable abnormalities in lung function tests.

Spontaneous pneumothorax and pneumomediastinum in IPF

Abstract. Patients with idiopathic pulmonary fibrosis (IPF) are at risk for a variety of acute pulmonary complications, including pneumothorax and pneumomediastinum. Our aim was to describe the radiographic and CT findings and to determine the frequency of complicating spontaneous pneumothorax and pneumomediastinum in patients with IPF. A retrospective study was performed including 78 consecutive patients who underwent CT scanning of the chest and who had confirmed IPF. The chest radiographs and CT scans were reviewed by two chest radiologists and classified as showing features of extra-alveolar air collections. The CT scans showed extra-alveolar air in 9 (11.2 %) of 78 patients (six females and three males; age range 26–90 years, mean age 65 years). Pneumothorax was demonstrated in 5 patients and mediastinal air collections in 4 patients. All patients had dyspnea for 1–48 months (mean 14 months). Of the five cases with pneumothorax, four developed acute onset of dyspnea and pleuritic chest pain, whereas 1 patient had a relatively stable functional status. Of the 4 patients with pneumomediastinum, three presented with nonpleuritic chest pain and acute dyspnea. Chest radiographs showed extra-alveolar air in 6 patients. Three cases were predicted to be negative by chest radiographs. Follow-up CT showed that air collections had resolved completely in 5 patients. Two patients died of respiratory failure within 4 months after CT. Extra-alveolar air should be recognized as a relatively common IPF-related complication. Chest CT is a useful imaging method in determining air collections in patients with IPF that become acutely breathless and their chest radiograph fails to reveal the presence of extra-alveolar air.

Fire eater's pneumonia: radiographic and CT findings.

Acute aspiration of petroleum by fire eaters can cause a distinct type of chemical pneumonitis known as fire eaters pneumonia that manifests on radiologic studies with unilateral or bilateral lung consolidations, well defined nodules, and pneumatoceles. We report three cases of fire eaters pneumonia that manifested with well-defined cavitary nodules (pneumatoceles) on radiographs and CT. One patient developed a bronchopleural fistula and spontaneous pyopneumothorax. CT is valuable for identifying and localizing complications to guide therapy.

Thin-Section CT Findings in Hematopoietic Stem Cell Transplantation Recipients with Respiratory Virus Pneumonia

OBJECTIVE The purpose of this study was to use serial thin-section CT scans to assess the incidence of respiratory viral infection and lung abnormalities in a large patient population at high risk of pulmonary complications. MATERIALS AND METHODS The study population consisted of 26 recipients of hematopoietic stem cell transplants who had proven respiratory viral pneumonia. In all cases, thin-section CT scans were obtained before fiberoptic bronchoscopy and bronchoalveolar lavage. The study included only patients in whom bronchoalveolar lavage fluid showed no evidence of organisms other than respiratory viruses. The CT scans were assessed for the presence, extent, and anatomic distribution of ground-glass attenuation, air-space consolidation, nodules, centrilobular branching structures (tree-in-bud), thickening of the bronchovascular bundles, and pleural effusion. RESULTS Areas of ground-glass attenuation were identified in 24 (92%) of 26 patients and were the only finding in eight patients. Multiple nodules, seen in 17 (65%) of 26 patients, measured 3-10 mm in diameter or were larger than 10 mm. The nodules had a centrilobular or random distribution. A tree-in-bud appearance was seen in six of the patients with centrilobular nodules. This pattern had a bilateral distribution and involved mainly the lower lung zones. CT revealed thickening of the bronchovascular bundles in 16 (61%) of the patients. Thickening was bilateral in 14 and unilateral in two patients. Bronchial wall thickening involved the lower lobes in six patients and had a patchy random distribution in the remaining nine patients. Air-space consolidation was present in nine (35%) of the cases. It had a lobular or subsegmental distribution in eight of the patients and a segmental distribution in one patient. Areas of consolidation were randomly distributed throughout the lungs in all cases. Less common findings included bilateral pleural effusion and bronchial dilatation. CONCLUSION Respiratory viral infection is common among adult recipients of hematopoietic stem cell transplants, occurring over a wide time span after transplantation. The presence of respiratory viral infection must be considered in any patient with new respiratory symptoms, fever, or findings at CT such as extensive or patchy areas of ground-glass opacities or a mixture of patterns, most commonly ground-glass attenuation, thickening of the bronchial walls, and multiple small nodules.

Human metapneumovirus infection in hematopoietic stem cell transplant recipients: high-resolution computed tomography findings.

Purpose: To review the high-resolution computed tomography (CT) findings in hematopoietic stem cell transplant (HCT) recipients who had proven human metapneumovirus (HMPV) pneumonia. Materials and Methods: The study included 5 HCT recipients who had proven HMPV pneumonia. The patients included 4 men and 1 woman ranging in age from 23 to 58 years (mean age = 42 years). The CT scans were assessed for the presence, appearance, size, and distribution of parenchymal abnormalities. Results: Human metapneumovirus was isolated in all 5 patients in this series. None of these patients had any other infectious organism identified in cultures or bronchoalveolar lavage. The predominant CT findings were bilateral abnormalities in all patients, consisting primarily of a mixture of patterns, including, most commonly, ground-glass attenuation and nodular opacities. Areas of ground-glass opacification had no zonal predominance and were bilateral, asymmetric, and patchily distributed. Multiple nodules were identified in 4 (80%) of 5 patients. Nodules were multiple; less than 5 nodules were identified in 1 case, and 5 to 10 nodules were identified in 3 cases. All nodules in all cases were less than 10 mm in diameter. Areas of air-space consolidation were identified in 2 (40%) patients. All patients were available for follow-up; lesions improved in 4 patients. Conclusion: The thin-section CT manifestations of HMPV pneumonia usually consist of a mixture of patterns, including, most commonly, ground-glass attenuation and nodular opacities.

Correlation between high-resolution computed tomography and galactomannan antigenemia in adult hematologic patients at risk for invasive aspergillosis

OBJECTIVES To analyse the predominant radiological pattern of pulmonary lesions in adult hematologic patients at risk for invasive aspergillosis (IA) together with the results of serial serum Aspergillus galactomannan antigen testing (GM). MATERIAL AND METHODS In a prospective study for patients at high risk of aspergillus pulmonary infection, serum GM were performed 2-3 times per week during the periods of high risk for IA and high-resolution CT (HRCT) was performed in case of abnormal chest X-ray (CXR) and/or persistent fever after 5 days of antibiotic treatment. Changes on HRCT scan were classified as airway IA and angioinvasive IA. IA was classified as proven or probable in accordance with the definitions stated by the European Organization for Research and Treatment of Cancer/Mycosis Study Group (EORTC-MS). Positive GM testing was not considered as microbiological criterion. RESULTS 38 hematological patients were diagnosed of probable (n=28) or proven (n=10) IA. 55% patients had a neutrophil count less than 500 mm(-3) (n=21), and 37% patients > or =2 risk factors for IA. All probable IA were diagnosed by bronchoalveolar lavage (BAL). Proven IA was reached by positive histopathologic and culture results of samples obtained by autopsy (n=4), percutaneous (n=3) or transbronchial biopsy (n=3). 18 patients had airway IA, and 60% had a GM level > or =1.5. 20 patients were diagnosed of angioinvasive IA from which 80% had a GM level > or =1.5. CONCLUSION Serum GM levels may be lower in patients with airway IA than in those with an angioinvasive form. HRCT and serum GM are complementary tests in the diagnosis of IA.

Air-leak syndromes in hematopoietic stem cell transplant recipients with chronic GVHD: high-resolution CT findings.

Objectives The purpose of this study was to determine the incidence and the high-resolution computed tomography findings of air-leak syndromes in a large group of hematopoietic stem cell (HSC) transplant recipients with proved chronic graft versus host disease (cGVHD). Materials and Methods High-resolution computed tomography scans of 9 allogeneic HSC transplant recipients (8 men, 1 woman; 19 to 45 years of age; median 28 y), with a proven diagnosis of cGVHD-related bronchiolitis obliterans syndrome (BOS) were reviewed for the presence, appearance, and distribution of abnormalities. Results Nine patients with cGVHD developed 10 episodes of spontaneous air-leak syndromes secondary to cGVHD-related BOS during the study period analyzed; for a 2-year estimated cumulative incidence of 2.1% (95% confidence interval 0.2% to 3.8%) its prevalence was 5.7% (95%CI: 2.6% to 10.5%). All cases were allogeneic HSC transplant recipients with cGVHD who acquired new respiratory symptoms and/or radiologic abnormalities. Pneumomediastinum and pneumothorax were present in 6 patients. Subcutaneous emphysema was identified in 3 patients and pulmonary interstitial emphysema in 2 patients. A combination of different air-leak syndromes was observed in 6 patients. Conclusion Air-leak syndromes represent an uncommon late complication in HSC transplant recipients with cGVHD-related BOS.

Imaging findings of sternal abnormalities

Abstract. Radiographic findings in the sternal abnormalities are often nonspecific, showing appearances from a localized benign lesion to an aggressive lesion as seen with infections and malignant neoplasms. A specific diagnosis of sternal abnormalities can be suggested on the basis of CT and MR characteristics. Familiarity with the presentation and variable appearance of sternal abnormalities may aid the radiologist is suggesting a specific diagnosis. We present among others characteristic radiographic findings of hemangioma, chondrosarcoma, hydatid disease, and SAPHO syndrome. In those cases in which findings are not specific, cross-sectional imaging modalities may help the clinician in their management.

Necrotizing aspergillosis of large airways: CT findings in eight patients

Purpose The aim of this study was to evaluate the CT findings of pathologically proven necrotizing aspergillosis of the large airways (necrotizing Aspergillus bronchitis). Method Medical records and imaging studies from two tertiary medical centers were reviewed for pathologically proven cases of necrotizing aspergillosis of the large airways. Fiberoptic bronchoscopic examination and CT scans of the chest were available in all cases. Two thoracic radiologists who were blinded to the clinical and pathologic data reviewed the thoracic CT scans retrospectively and reached a final decision. The CT images were evaluated for the presence, distribution, and extent of CT findings. Results The study included eight patients, seven men and one woman, ranging in age from 28 to 67 years (mean age 46 years). All patients had histopathologically proved necrotizing Aspergillus of the large airways and no other superimposed infections. Six patients had leukemia, one had chronic liver disease, and one had chronic obstructive lung disease. All patients had bronchial wall thickening and focal bronchial narrowing involving a lobar or segmental bronchus. The bronchial narrowing was irregular or nodular in seven patients and smooth in one. Atelectasis distal to a narrowed bronchus was present in five patients. Conclusion The CT findings of necrotizing bronchial aspergillosis include bronchial wall thickening, which is often nodular, and narrowing of the bronchial lumen, which is often associated with distal atelectasis.