Thin-Section CT Findings in 32 Immunocompromised Patients with Cytomegalovirus Pneumonia Who Do Not Have AIDS

OBJECTIVE

The aim of this study was to review the thin-section CT findings in 32 immunocompromised patients without AIDS who had proven Cytomegalovirus pneumonia.

MATERIALS AND METHODS

The causes of immunocompromise included bone marrow (n = 25) or solid organ transplantation (n = 5) and corticosteroid therapy (n = 2). The patients included 16 men and 16 women ranging in age from 22 to 70 years (mean age, 43 years). The CT scans were retrospectively reviewed by two thoracic radiologists for the presence, appearance, and distribution of parenchymal abnormalities.

RESULTS

Bilateral abnormalities were seen in all patients. Areas of ground-glass opacification were seen in 21 (66%) of 32 patients. Ground-glass opacification was the predominant CT feature in nine cases (28%). In 19 of 32 patients, ground-glass attenuation was associated with other abnormalities. Multiple nodules were identified in 19 patients (59%). Nodules were bilateral in 15 patients and unilateral in four patients. Nodules were the only CT finding in three patients (9%). Areas of air-space consolidation were identified in 19 patients (59%). Air-space consolidation was the only CT finding in one patient (3%). Other less common CT findings included thickening of the bronchovascular bundles (n = 7) and the tree-in-bud appearance (n = 4). Pleural effusions were seen in seven patients.

CONCLUSION

The thin-section CT manifestations of Cytomegalovirus pulmonary infection usually consist of a mixture of patterns, most commonly ground-glass attenuation, areas of consolidation, and small nodules.

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 kappa 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.

Disorders of the Small Airways: High-Resolution Computed Tomographic Features

Several infectious and noninfectious processes may affect predominantly or exclusively the small airways and result in reversible or irreversible abnormalities. Small-airway diseases can be considered as synonymous with bronchiolitis and can be classified into three main categories: (a) obliterative (constrictive) bronchiolitis, (b) cellular bronchiolitis, and (c) respiratory bronchiolitis. The introduction of high-resolution computed tomography (HRCT) has led to a considerable improvement in our ability to diagnose small-airway diseases. The characteristic HRCT findings of obliterative bronchiolitis consist of areas of decreased attenuation and vascularity with blood flow redistribution resulting in areas of increased lung attenuation and vascularity ("mosaic perfusion" pattern). In cellular bronchiolitis, the characteristic HRCT findings consist of centrilobular nodules and branching opacities ("tree-in-bud" pattern). Finally, bilateral areas of ground-glass attenuation and/or poorly defined centrilobular nodules are characteristic of respiratory bronchiolitis and respiratory bronchiolitis-associated interstitial lung disease (RB-ILD). This article reviews the clinical, pathological, and HRCT features of some of the most common small-airway diseases.

The retrotracheal space: normal anatomic and pathologic appearances

A variety of diseases can arise from the normal contents of the retrotracheal space or from adjacent structures. Mediastinal diseases in the retrotracheal space typically manifest radiographically as a contour abnormality or an area of increased opacity, although computed tomography (CT) or magnetic resonance (MR) imaging is usually required for diagnosis. The most common aortic arch anomaly, a right subclavian artery that originates from an otherwise normal left-sided aortic arch, appears at posteroanterior chest radiography as an obliquely oriented soft-tissue area of increased opacity that extends superiorly to the right from the superior margin of the aortic arch. CT and MR imaging can reveal associated vascular or mediastinal abnormalities. Aortic aneurysms and pseudoaneurysms can manifest radiographically as fusiform or saccular masslike lesions that protrude into the retrotracheal space. Thoracic MR imaging and spiral CT angiography are the diagnostic procedures of choice for evaluating diverse pathologic conditions of the thoracic aorta. Esophageal diseases can manifest as an abnormality in the retrotracheal space, which may be the initial clue to the diagnosis. At CT, lymphatic malformations in the mediastinum manifest as lobular, multicystic tumors that surround and infiltrate adjacent mediastinal structures. Familiarity with the normal radiologic appearance of the retrotracheal space and with the clinical manifestations of diseases that affect the retrotracheal space and adjacent structures can facilitate detection, diagnosis, and management.

Thoracic complications of esophageal disorders

Abnormalities of the esophagus are common, and complications associated with these disorders and diseases can involve the mediastinum, tracheobronchial tree, and lungs. The most common complications include mediastinitis secondary to esophageal perforation or postoperative anastomotic leak, or both; empyema due to fistula formation; and aspiration pneumonia. The authors reviewed the radiologic appearances of those and other common thoracic complications associated with esophageal disorders to facilitate early detection, diagnosis, and management. Computed tomographic (CT) findings of acute mediastinitis secondary to esophageal perforation may include esophageal thickening, extraluminal gas, pleural effusion, single or multiple abscesses, and extraluminal contrast medium. The radiologic manifestations of pneumonia secondary to tracheoesophageal fistula are variable, depending on the spread and severity of the aspiration. The most common radiographic pattern is that of bronchopneumonia with scattered air-space opacities. CT has been regarded as the imaging modality of choice for the evaluation of suspected esophagopleural fistula, because the site of communication between the pleural space and the esophagus can often be seen. An awareness of the radiologic manifestations of these complications is thus required to facilitate early diagnosis.

Unusual primary lung tumors: a radiologic-pathologic overview

Although the great majority of lung carcinomas are histologically characterized as adenocarcinoma, squamous cell carcinoma, large cell undifferentiated carcinoma, or small cell carcinoma, a variety of rare benign and malignant lung tumors may sporadically affect the lung. Several nonneoplastic tumorlike lesions are seen infrequently but are also part of the differential diagnosis for lung masses. Conventional radiographic findings, although of limited value in the diagnosis of these entities, should be examined carefully when lung tumors are suspected. Computed tomography (CT) is well suited for making a definitive diagnosis of some disease processes. CT helps determine the location and features of the lesions and depicts associated findings to help document the extent of disease. The differential diagnosis can be narrowed when there are typical CT features (eg, the presence of fat in lipoid pneumonia). Although unusual primary lung tumors are difficult to diagnose on the basis of imaging findings alone because such findings are nonspecific in the majority of cases, cross-sectional imaging can play an important role in the diagnostic work-up of these unusual tumors by delineating their extent and directing the radiologist or bronchoscopist to the appropriate biopsy site.

Invasive pulmonary aspergillosis in patients with hematologic malignancies: survival and prognostic factors

BACKGROUND AND OBJECTIVES

Despite improvements made in its early diagnosis and effective treatment, invasive pulmonary aspergillosis (IPA) remains a devastating opportunistic infection. In this retrospective study we have reviewed all consecutive cases of IPA diagnosed in adult patients with hematologic malignancies in our center from 1995 to 2000 to determine survival and prognostic factors.

DESIGN AND METHODS

Forty-one patients were included in the study. Ante-mortem classification of cases of IPA were: 4 definite, 10 highly probable, 19 probable and 8 possible cases; all these last eight patients were later upgraded to definite IPA at post-mortem examination. Clinical charts were reviewed and factors possibly affecting the outcome of IPA were analyzed.

RESULTS

All but two patients received chemotherapy and/or immunosuppresive therapy before the onset of IPA (conventional chemotherapy = 24, allogeneic stem cell transplantation [SCT] = 12, autologous SCT = 3). At IPA diagnosis 28 patients were neutropenic (< 0.5 x 10(9)/L) for a median of 25 days (range 7-135), and 10 allogeneic SCT patients were receiving corticosteroids for graft-versus-host-disease. All but two patients received antifungal treatment for IPA. The median delay from diagnosis to start of therapy was two days (range 0-20). The median follow-up after the first symptom or sign of IPA was 42 days with a maximum follow-up of 61 months. The actuarial 4-month infection-free survival was 40% (95% CI 25% to 55%). Thirty-three patients died during follow-up and IPA was implicated in the patients' death in 24 cases (75%). In multivariate analysis prolonged survival was associated with recovery of neutropenia during treatment (p = 0.001) and not having received an allogeneic SCT (p = 0.003).

INTERPRETATION AND CONCLUSIONS

Despite prompt initiation of antifungal therapy, survival of patients with a hematologic malignancy and IPA is currently low. Perhaps the introduction of more sensitive diagnostic methods will allow the onset of intensive therapy prior to the appearance of more advanced clinical symptoms and/or radiological signs, and the time will come to test whether earlier and more intensive therapy will improve survival.

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.

High-resolution CT of lung disease related to collagen vascular disease

Although connective tissue diseases may have similar radiographic appearances, a variety of pathologic processes can be seen in the lung of these patients. In such circumstances, early recognition of lung involvement is now easily demonstrated by imaging methods. The development of thin-section and dynamic CT techniques has significantly improved diagnostic accuracy. Moreover, expiratory HRCT is a helpful technique in demonstrating air trapping in these patients. The radiologist plays a significant role in the evaluation of pulmonary manifestations of connective tissue diseases.

Imaging of pneumonia: trends and algorithms

Pneumonia is one of the major infectious diseases responsible for significant morbidity and mortality throughout the world. Imaging plays a crucial role in the detection and management of patients with pneumonia. This review article discusses the different imaging methods used in the diagnosis and management of suspected pulmonary infections. The imaging examination should always begin with conventional radiography. When the results of routine radiography are inconclusive, computed tomography is mandatory. A combination of pattern recognition with knowledge of the clinical setting is the best approach to the pulmonary infectious processes. A specific pattern of involvement can suggest a likely diagnosis in many instances. In acquired immune deficiency syndrome patients, diffuse ground-glass and interstitial infiltrates are most commonly present in Pneumocystis carinii pneumonia whereas in the nonimmunosuppressed patients, a segmental lobar infiltrate is suggestive of a bacterial pneumonia. Round pneumonia is most often encountered in children than adults and is most often caused by Streptococcus pneumoniae. Different combinations of parenchymal and pleural abnormalities may be suggestive for additional diagnoses. When an infectious pulmonary process is suspected, knowledge of the varied radiographic manifestations will narrow the differential diagnosis, helping to direct additional diagnostic measures, and serving as an ideal tool for follow-up examinations.

Spectrum of pulmonary aspergillosis: histologic, clinical, and radiologic findings

Aspergillosis is a serious pathologic condition caused by Aspergillus organisms and is frequently seen in immunocompromised patients. At computed tomography (CT), saprophytic aspergillosis (aspergilloma) is characterized by a mass with soft-tissue attenuation within a lung cavity. The mass is typically separated from the cavity wall by an airspace ("air crescent" sign) and is often associated with thickening of the wall and adjacent pleura. CT findings in allergic bronchopulmonary aspergillosis consist primarily of mucoid impaction and bronchiectasis involving predominantly the segmental and subsegmental bronchi of the upper lobes. Aspergillus necrotizing bronchitis may manifest as an endobronchial mass, obstructive pneumonitis or collapse, or a hilar mass. Bronchiolitis is characterized by centrilobular nodules and branching linear or nodular areas of increased attenuation ("tree-in-bud" pattern). Obstructing bronchopulmonary aspergillosis mimics allergic bronchopulmonary aspergillosis at CT and manifests as bilateral bronchial and bronchiolar dilatation, large mucoid impactions, and diffuse lower lobe consolidation caused by postobstructive atelectasis. Characteristic CT findings in angioinvasive aspergillosis consist of nodules surrounded by a halo of ground-glass attenuation ("halo sign") or pleura-based, wedge-shaped areas of consolidation. Although imaging findings in pulmonary aspergillosis may be nonspecific, in the appropriate clinical setting, familiarity with the CT findings may suggest or even help establish the diagnosis.

Mycobacterium genavense infection in AIDS: imaging findings in eight patients

This retrospective study included eight HIV-positive patients with a M. genavense infection. Seven of these patients had a CT scan of the abdomen and a US examination, whereas one patient with pulmonary symptoms had conventional chest radiographs and thin-section CT scan of the thorax. Multiple large retroperitoneal and mesenteric lymph nodes were demonstrated in seven patients; low-attenuation centers within enlarged nodes were identified in two patients. On CT scans two cases showed circumferential wall thickening of the proximal small bowel with a deep ulceration in one of these patients. Additional findings included focal lesions in the liver (n = 1), spleen (n = 2), splenomegaly (n = 6), and hepatomegaly (n = 4). The CT scans from the thoracic examination demonstrated multiple diffuse nodular infiltrates in both lungs. M. genavense infection should be considered in the differential diagnosis of AIDS patients with CD4 counts below 100 cells/mm3 presenting with abdominal lymphadenopathy, multinodular or homogeneous hepatosplenic enlargement and circumferential thickening of the small bowel wall.

Bronchoscopy guided by high-resolution computed tomography for the diagnosis of pulmonary infections in patients with hematologic malignancies and normal plain chest X-ray

BACKGROUND AND OBJECTIVES

High-resolution computed tomography (HRCT) of the chest is able to demonstrate the presence of pulmonary infiltrates in febrile neutropenic patients with normal chest X-rays. Fiberoptic bronchoscopy with bronchoalveolar lavage (BAL) is a safe procedure for the etiological diagnosis of pulmonary infiltrates in oncohematologic patients. The objective of this study was to determine the diagnostic yield and subsequent therapeutic changes of a protected BAL (p-BAL) guided by HRCT in febrile oncohematologic patients unresponsive to broad-spectrum antibiotics with a normal chest X-ray.

DESIGN AND METHODS

Twenty-two episodes from 20 oncohematologic patients were included: group A, 9 episodes (8 patients) with no respiratory symptoms and group B, 13 episodes (12 patients) with signs or symptoms of pulmonary infection. HRCT and p-BAL were performed in all episodes within the first 24 hours.

RESULTS

HRCT showed abnormalities in all 22 episodes (bilateral abnormalities in 14 of the 22 episodes [64%]) and the most frequent pattern was ground-glass infiltrate (7 out of 22 episodes). An infectious agent was isolated in 12 of the 22 episodes, 5 in group A and 7 in group B with a diagnostic yield of 54%. Antimicrobial therapy was modified in 12 of the 22 episodes (54%): 5 in group A and 7 in group B. In 6 episodes, treatment was changed according to HRCT results and in the remaining 6 due to positive microbiologic results. Modifications in empirical therapy were associated with a favorable response in 44% episodes of group A and in 31% of group B.

INTERPRETATION AND CONCLUSIONS

Oncohematologic patients with fever of unknown origin unresponsive to empirical antibiotics and with a normal chest X-ray can be candidates to undergo a HRCT. This subgroup of high-risk patients can benefit from a combined strategy consisting of BAL guided by a previous HRCT.

Spontaneous reversibility of "pleural thickening" in a patient with semi-invasive pulmonary aspergillosis: radiographic and CT findings

We present serial radiographic and CT findings of spontaneous reversibility of "pleural thickening" in a patient with proved semi-invasive pulmonary aspergillosis who developed bilateral intracavitary aspergillomas. To the best of our knowledge, this is the first report in the literature of this feature. Radiologists should be aware that pleural thickening in patients with semi-invasive aspergillosis does not necessarily indicate irreversible pleural fibrosis.

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 eater's pneumonia that manifests on radiologic studies with unilateral or bilateral lung consolidations, well defined nodules, and pneumatoceles. We report three cases of fire eater's 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.

Aspiration diseases: findings, pitfalls, and differential diagnosis

The aspiration of different substances into the airways and lungs may cause a variety of pulmonary complications. These disease entities most commonly involve the posterior segment of the upper lobes and the superior segment of the lower lobes. Esophagography and computed tomography (CT) are especially useful in the evaluation of aspiration disease related to tracheoesophageal or tracheopulmonary fistula. Foreign body aspiration typically occurs in children and manifests as obstructive lobar or segmental overinflation or atelectasis. An extensive, patchy bronchopneumonic pattern may be observed in patients following massive aspiration of gastric acid or water. CT is the modality of choice in establishing the diagnosis of exogenous lipoid pneumonia, which can result from aspiration of hydrocarbons or of mineral oil or a related substance. Aspiration of infectious material manifests as necrotizing consolidation and abscess formation. The relatively low diagnostic accuracy of chest radiography in aspiration diseases can be improved with CT and by being familiar with the clinical settings in which specific complications are likely to occur. Recognition of the varied clinical and radiologic manifestations of these disease entities is imperative for prompt, accurate diagnosis, resulting in decreased morbidity and mortality rates.

Spontaneous pneumothorax and pneumomediastinum in IPF

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.

Semiinvasive pulmonary aspergillosis in chronic obstructive pulmonary disease: radiologic and pathologic findings in nine patients

OBJECTIVE

The purpose of this study is to assess the radiographic, thin-section CT, and histologic findings of semiinvasive aspergillosis in patients with chronic obstructive pulmonary disease (COPD).

MATERIALS AND METHODS

The study included nine patients with COPD seen at the Hospital de Sant Pau during a 3-year period who had histopathologically proven aspergillosis with tissue invasion. Chest radiography and thin-section (2-mm collimation) CT of the chest were available in all cases.

RESULTS

Nine patients had semiinvasive aspergillosis proven at autopsy (n = 7) or by thoracoscopically guided lung biopsy (n = 2). The radiologic findings consisted of parenchymal consolidation (n = 6) and nodules larger than 1 cm in diameter (n = 3). Parenchymal consolidation involved the upper lobes in five patients and was bilateral in four. Cavitation was present in two of the patients with consolidation and in two of the patients with nodular opacities. Adjacent pleural thickening was revealed by CT in four patients. Histologically, the areas of consolidation represented active inflammation and intraalveolar hemorrhage containing Aspergillus organisms. In the three patients with multiple cavitated nodules, a variable degree of central necrosis was observed. The inflammatory infiltrate extended into the surrounding lung parenchyma, and adjacent areas of hemorrhage were also seen. Aspergillus colonies were identified within the lung tissue.

CONCLUSION

Upper lobe consolidation or multiple nodules in patients with COPD should raise the possibility of semiinvasive aspergillosis.

[The prognostic factors of invasive pulmonary aspergillosis in patients with chronic pneumopathy]

OBJECTIVES

a) To determine in patients with chronic respiratory disease the risk factors for death due to semi-invasive and invasive pulmonary aspergillosis (SIPA), and b) to describe the clinical features of SIPA in such patients.

METHOD

Twenty-one patients with chronic respiratory disease were enrolled (9 with chronic obstructive pulmonary disease, 2 asthmatics and 3 with bronchiectasis, 5 with post-tubercular sequelae and 2 mixed cases). A diagnosis of SIPA was established in our hospital when, in a patient with a clinical picture consistent with such a diagnosis, the fungus was isolated in bronchial secretions or parenchymal pulmonary specimens were obtained during autopsy.

RESULTS

The most common symptoms were dyspnea (81%), cough (67%) and expectoration (62%) increasing over the levels usual for patients with chronic respiratory disease. Hemoptysis was present in only 14%. Eight patients (38%) died as a result of SIPA. A comparison of those surviving and non-surviving patients revealed that the latter had significantly higher LDH levels and white cell counts, and significantly lower total plasma protein and platelet counts.

CONCLUSIONS

a) Low protein levels and high LDH levels and white cell counts with thrombopenia are indicators of poor prognosis in chronic respiratory disease patients with SIPA, and b) such patients do not usually present signs or symptoms that lead to a suspicion of SIPA given that such signs are typical of failing compensatory mechanisms in the disease itself.

Acute Q fever in adult patients: report on 63 sporadic cases in an urban area

We report here 63 sporadic urban cases of acute Q fever diagnosed in 1985-1997. Fifty-eight men and five women were included; the mean age (+/- SD) was 35.6 (+/- 10.2) years. Twenty-six patients had pneumonia, 30 had hepatitis, and 7 had a self-limited febrile illness. The most frequent radiological abnormalities were lobar or segmental alveolar opacities involving right lower lobes. Chronic bronchitis was significantly more frequent among patients with pneumonic Q fever (P = .01). Thirty-two patients' illnesses were diagnosed through seroconversion, 12 by a fourfold increase in serum antibody titer, and 19 by initial high titers. Patients who initially received doxycycline had a significantly shorter duration of fever than those treated with erythromycin or other antibiotics (P = .0001 and P = .0004, respectively). No patient died. Acute Q fever affects mainly urban men, most frequently causing hepatitis, except in those with chronic bronchitis, who more frequently develop pneumonia. Hepatic Q fever presented with more pronounced increases in liver function test values than did pneumonic Q fever. Treatment with doxycycline caused a significant reduction in the duration of fever.

Bronchiolar inflammatory diseases: high-resolution CT findings with histologic correlation

Bronchiolar diseases pose a significant challenge to the clinician confronted with the evaluation and management of the affected patient. A variety of infectious and non-infectious diseases may affect the bronchioles causing either reversible or fixed bronchiolar obstruction. High-resolution CT (HRCT) is currently the best imaging modality for evaluation of small-airway disease. In fact, a wide spectrum of abnormalities are identified at HRCT in patients with bronchiolar diseases. These abnormalities are shown on HRCT in the presence of a normal or unclear chest radiograph. Additionally, HRCT performed at suspended full expiration may demonstrate the physiologic consequences of bronchiolar disease, e. g., air trapping. The differential diagnosis of pulmonary manifestations of bronchiolar diseases at HRCT is based on the different patterns of abnormality. Familiarity with the presentation of different bronchiolar inflammatory processes aid the radiologist in narrowing the differential diagnosis or even in suggesting a specific diagnosis. This article reviews the HRCT findings of various bronchiolar inflammatory diseases outlining their pathologic features. Knowledge of the underlying gross and microscopic pathologic features leads to a better understanding of their CT appearances.

Hydatid pulmonary embolism from a ruptured mediastinal cyst: high-resolution computed tomography, angiographic, and pathologic findings

Hydatid disease is a parasitic infestation caused by the larval stage of a tapeworm of the genus Echinococcus. This report describes an extremely rare complication of echinococcal disease in which severe pulmonary hypertension developed after massive hydatid pulmonary embolism.