Cristopher A. Meyer

Diffuse Cystic Lung Disease at High-Resolution CT

OBJECTIVE This article will illustrate and describe the spectrum of diseases associated with air cysts at high-resolution CT (HRCT). CONCLUSION HRCT is an important modality in the evaluation of interstitial lung disease to include cystic lung disease. Although most commonly associated with lymphangioleiomyomatosis or Langerhans cell histiocytosis, cystic lung disease is increasingly being recognized as a feature of other entities. Awareness of the spectrum of HRCT findings associated with these diseases may help the trained observer narrow the differential diagnosis.

Pneumocystis jiroveci Pneumonia: High-Resolution CT Findings in Patients With and Without HIV Infection

OBJECTIVE The purpose of this essay is to review the spectrum of high-resolution CT findings of Pneumocystis jiroveci pneumonia in immunocompromised patients with and without HIV infection. CONCLUSION Pneumocystis jiroveci pneumonia is a common opportunistic infection affecting immunosuppressed patients. High-resolution CT may be indicated for evaluation of immunosuppressed patients with suspected pneumonia and normal chest radiographic findings. The most common high-resolution CT finding of Pneumocystis jiroveci pneumonia is diffuse ground-glass opacity. Consolidation, nodules, cysts, and spontaneous pneumothorax also can develop.

Official American Thoracic Society/Japanese Respiratory Society Clinical Practice Guidelines: Lymphangioleiomyomatosis Diagnosis and Management

BACKGROUND Lymphangioleiomyomatosis (LAM) is a rare cystic lung disease that primarily affects women. The purpose of these guidelines is to provide recommendations for the diagnosis and treatment of LAM. METHODS Systematic reviews were performed to summarize evidence pertinent to our questions. The evidence was summarized and discussed by a multidisciplinary panel. Evidence-based recommendations were then formulated, written, and graded using the Grading of Recommendations, Assessment, Development, and Evaluation approach. RESULTS After considering the panels confidence in the estimated effects, the balance of desirable (i.e., benefits) and undesirable (i.e., harms and burdens) consequences of treatment, patient values and preferences, cost, and feasibility, recommendations were formulated for or against specific interventions. These included recommendations for sirolimus treatment and vascular endothelial growth factor D testing and recommendations against doxycycline and hormonal therapy. CONCLUSIONS Evidence-based recommendations for the diagnosis and treatment of patients with LAM are provided. Frequent reassessment and updating will be needed.

CT Findings of Pulmonary Nocardiosis

OBJECTIVE Nocardiosis is an opportunistic infection that primarily affects the lungs. Most infected patients have deficits in cell-mediated immunity such as those with AIDS, transplant recipients, and those receiving corticosteroid therapy. We review the various CT appearances of pulmonary nocardiosis and discuss the differential diagnosis. CONCLUSION Common CT findings include lung consolidation and nodules and masses. Cavitation may occur. Chest wall involvement develops in a small number of patients.

Workers with Libby Amphibole Exposure: Retrospective Identification and Progression of Radiographic Changes

PURPOSE To assess how early pleural and/or parenchymal abnormalities consistent with asbestos exposure could be ascertained and to identify factors associated with progression. MATERIALS AND METHODS Informed consent was obtained under an institutional review board-approved protocol. Multiple sequential chest radiographs obtained between 1955 and 2004 in 84 workers exposed to amphiboles associated with vermiculite in the town of Libby, Montana, were studied. A panel of three NIOSH B readers reviewed each workers longitudinal chest radiograph series in reverse chronologic order and achieved a consensus reading for each radiograph. Measures of exposure were compared between workers with and those without progression of parenchymal and pleural abnormalities. RESULTS Because of the way the study was designed, all subjects had pleural (n = 84) and/or parenchymal (n = 26) abnormalities on the most recent chest radiograph. Compared with other investigations that used different methods, this investigation revealed shorter latency periods (defined as the interval between date of hire and date of earliest radiographic detection) for circumscribed pleural plaque (median latency, 8.6 years) and pleural calcification (median latency, 17.5 years). Pleural abnormalities progressed in 64 workers, while parenchymal abnormalities progressed in 14. No significant differences were found with regard to measures of exposure between workers with and those without progression. CONCLUSION The latency period for the development of pleural plaques may be shorter than previously reported. Early plaques are subtle and may not be detectable except at retrospective review.

Missed lung cancer on chest radiography and computed tomography : Imaging and medicolegal issues

Missed lung cancer is an important medicolegal issue and is the second leading cause for malpractice actions against radiologists. Contributing factors to overlooked lung cancer can be ascribed to observer performance, lesion characteristics, and technical considerations. Of these, errors related to observer performance are probably the most important. Missed lung cancer does not necessarily constitute malpractice, but lesions of high conspicuity are more likely to be associated with an adverse legal outcome. Multiple strategies have been advocated to reduce the frequency of missed lung cancer. Several studies have emphasized the importance of careful comparison of the current radiograph with one or more prior examinations.

HRCT/CT and associated spirometric effects of low Libby amphibole asbestos exposure.

Objective: Evaluate the relationship between cumulative fiber exposure and high-resolution or conventional chest computed tomography (HRCT/CT) changes and spirometry of workers with Libby amphibole asbestos exposure. Methods: Of the original 1980 cohort (n = 513), 431 were living and asked to participate. Images were evaluated for localized pleural thickening (LPT), diffuse pleural thickening (DPT), and parenchymal changes. Results: A total of 306 participants provided either HRCT/CT scans (n = 191) or chest radiographs (n = 115). Of the 191 with HRCT/CT, 52.9% had pleural changes and 13.1% had parenchymal changes. Those with LPT only, LPT and/or DPT, or DPT and/or parenchymal changes had mean 6.1, 8.0, and 18.0 loss in percent predicted forced vital capacity, respectively. Conclusions: Exposure to vermiculite containing amphibole fibers is associated with pleural and parenchymal HRCT/CT changes at low cumulative fiber exposure; these changes are associated with spirometric decrements.

Imaging of intrathoracic metastases of nonseminomatous germ cell tumors

Radiologic imaging is crucial in the evaluation of intrathoracic metastatic nonseminomatous germ cell tumors. Helical CT is the workhorse of radiologic staging and is sensitive in the detection of parenchymal nodules and mediastinal lymphadenopathy. CT may also demonstrate other less common sites of metastatic disease. Although, currently, no radiologic procedure is effective in distinguishing viable tumor or teratoma from residual fibrosis and necrosis, cross-sectional imaging remains essential in the presurgical evaluation of potential metastatic disease. FDG PET and CT-guided needle biopsy may be useful in select, high-risk patients.

Accuracy of chest high-resolution computed tomography in diagnosing diffuse cystic lung diseases

The diffuse cystic lung diseases (DCLDs) are a group of pathophysiologically heterogeneous processes characterised by the presence of multiple, thin-walled, air-filled spaces within the pulmonary parenchyma [1]. The differential diagnosis of DCLDs includes lymphangioleiomyomatosis (LAM), follicular bronchiolitis (FB), lymphocytic interstitial pneumonia (LIP), Birt–Hogg–Dubé syndrome (BHD), pulmonary Langerhans cell histiocytosis (PLCH), amyloidosis, light chain deposition disease, cystic metastases, infectious entities such as Pneumocystis, and other aetiologies [2]. Bronchiectasis and bullous changes seen in chronic obstructive pulmonary disease can also produce high-resolution computed tomography (HRCT) patterns that mimic the DCLDs. Correct diagnosis of diffuse cystic lung diseases is established in most cases by critical review of HRCT features http://ow.ly/NvrCc

Occupational and environmental lung disease.

Occupational and environmental lung disease remains a major cause of respiratory impairment worldwide. Despite regulations, increasing rates of coal workers pneumoconiosis and progressive massive fibrosis are being reported in the United States. Dust exposures are occurring in new industries, for instance, silica in hydraulic fracking. Nonoccupational environmental lung disease contributes to major respiratory disease, asthma, and COPD. Knowledge of the imaging patterns of occupational and environmental lung disease is critical in diagnosing patients with occult exposures and managing patients with suspected or known exposures.