An estimated 180,000 new cases of lung cancer will be diagnosed in the U.S. this year, and lung cancer accounts for approximately 25% of all cancer deaths. Most lung cancers are initially detected on chest radiographs, but many benign lesions have radiologic characteristics similar to malignant lesions. Thus, additional studies are required for further evaluation. CT is most frequently used to provide additional anatomic and morphologic information about lesions, but it is limited in distinguishing between benign and malignant abnormalities. Because of the indeterminate results obtained from anatomic images, biopsy procedures, including thoracoscopy and thoracotomy, may be used even though one half of the lesions removed are benign and do not need to be removed. Fluorodeoxyglucose (FDG) PET imaging provides physiologic and metabolic information that characterizes lesions that are indeterminate by CT, accurately stages the distribution of lung cancer and provides prognostic information. FDG PET imaging takes advantage of the increased accumulation of FDG in transformed cells and is sensitive (approximately 95%) to the detection of cancer in patients who have indeterminate lesions on CT. The specificity (approximately 85%) of PET imaging is slightly less than its sensitivity because some inflammatory processes, such as active granulomatous infections, avidly accumulate FDG. The high negative predictive value of PET suggests that lesions considered negative on the study are benign, biopsy is not needed and radiographic follow-up is recommended. Several studies have documented the increased accuracy of PET compared with CT in the evaluation of the hilar and mediastinal lymph-node status in patients with lung cancer. Whole-body PET studies detect metastatic disease that is unsuspected by conventional imaging and demonstrate some of the anatomic abnormalities detected by CT to be benign lesions. Management changes have been reported in up to 41% of patients on the basis of the results of whole-body studies. (+info)
Transthoracic needle aspiration biopsy for the diagnosis of localised pulmonary lesions: a meta-analysis.
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BACKGROUND: Persisting controversy surrounds the use of transthoracic needle aspiration biopsy (TNAB) stemming from its uncertain diagnostic accuracy. A systematic review and meta-analysis was therefore conducted to evaluate the accuracy of TNAB for the diagnosis of solitary or multiple localised pulmonary lesions. METHODS: Searches for English literature papers in Index Medicus (1963-1965) and Medline (1966-1996) were performed and the bibliographies of the retrieved articles were systematically reviewed. Articles evaluating the accuracy of TNAB in series of consecutive patients presenting with solitary or multiple pulmonary lesions were considered. Only papers in which >/=90% of patients were given a final diagnosis according to an appropriate reference standard were included in the meta-analysis. RESULTS: A total of 48 studies were included and five meta-analyses were conducted according to four diagnostic thresholds. From the pooled sensitivity and specificity corresponding to each diagnostic threshold, associated likelihood ratios (LRs) were derived for malignant disease as follows: (1) malignant versus all other categories, LR = 72; (2) malignant or suspicious versus all others, LR = 49; (3) suspicious versus all categories but malignant, LR = 15; (4) benign versus all others, LR = 0.07; and (5) specific benign diagnosis versus all others, LR = 0.005. Differences in methodological quality of the studies, needle types, or whether a cytopathologist participated in the procedure failed to explain the heterogeneity of the results found in almost every meta-analysis. Given a 50% probability of malignancy prior to the TNAB, post-test probabilities of malignancy upon receiving the results would be malignant, 99%; suspicious, 94%; non-specific benign, 7%; and benign with a specific diagnosis, 0.6%. CONCLUSIONS: Given the intermediate pre-test probabilities that would probably lead to performing TNAB, findings of "malignant" or of a specific diagnosis of a benign condition provide definitive results. Findings of "suspicious" markedly increase the probability of malignancy, and "benign" markedly decreases it but may not be considered definitive. (+info)
Role of Tc-99m MIBI in the evaluation of single pulmonary nodules: a preliminary report.
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BACKGROUND: Survival in bronchial carcinoma is closely related to the stage of the disease at the time of diagnosis and a single pulmonary nodule represents a potentially curable stage. This study was conducted to assess the feasibility of using Tc-99m labelled 2-methoxy isobutyl isonitrile (MIBI) to differentiate benign from malignant single pulmonary nodules. METHODS: A prospective study was conducted in the outpatient pulmonary clinic at the Cleveland Clinic Foundation. Twenty five patients with single pulmonary nodules considered indeterminate by their physicians and undergoing a procedure for tissue diagnosis were evaluated by Tc-99m MIBI SPECT scanning prior to definitive testing. Assessment of MIBI uptake was done qualitatively (subjectively) and quantitatively and correlated with the histopathology and nodule size. RESULTS: Of the 21 patients with malignant lesions, 18 had increased uptake of MIBI corresponding to the location of the nodule and were considered positive. The predominant tumour types were large cell (n = 5) and adenocarcinoma (n = 10). All four patients with benign lesions had negative MIBI scans. For malignancy the overall specificity was 100%, sensitivity was 85.7%, positive predictive value was 100%, and negative predictive value was 57%. Quantitative uptake of MIBI correlated with the diameter of the nodule with a correlation coefficient of 0.61 by Spearman's rank sum test. This relationship was statistically significant (p = 0.02). CONCLUSION: This preliminary study suggests that Tc-99m MIBI has a very high specificity and positive predictive value for malignant single pulmonary nodules and might be a useful non-invasive diagnostic modality in their management. (+info)
Pulmonary cytolytic thrombi: a newly recognized complication of stem cell transplantation.
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Over the past 5 years we have recognized a new pulmonary complication of hematopoietic stem cell transplantation (HSCT) associated with fever and pulmonary nodules termed 'pulmonary cytolytic thrombi' (PCT). Retrospective analysis of medical and radiographic records and pathologic material from 13 HSCT recipients with PCT and a review of the Blood and Marrow Transplant Database for all patients with radiographic evidence of pulmonary nodules or who underwent open-lung biopsy from 1 January 1993 to 31 December 1998 (n = 1228) were performed. The median age of patients with PCT was 11.9 years (range, 1.3-29.7 years). All patients developed fever at a median of 72 days (range, 8-343 days) post transplant, followed by pulmonary nodules on chest CT. Eleven patients were receiving therapy for active GVHD (acute, grades I-IV (n = 10); extensive chronic (n = 1)). Biopsy of the pulmonary nodules revealed a unique pattern of necrotic, basophilic thromboemboli with amorphous material suggestive of cellular breakdown products. This was descriptively labeled 'pulmonary cytolytic thrombi'. Immunohistochemical staining revealed entrapped leukocytes and disrupted endothelium, but was negative for histiocytes. Cultures and immunohistochemical stains were negative for infectious agents. Empiric therapy included systemic corticosteroids (n = 9) and amphotericin (n = 7). Nine patients survive with resolution of PCT at a median follow-up of 1.5 years. Bone Marrow Transplantation (2000) 25, 293-300. (+info)
Low-cost soft-copy display accuracy in the detection of pulmonary nodules by single-exposure dual-energy subtraction: comparison with hard-copy viewing.
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This study endeavored to clarify the usefulness of single-exposure dual-energy subtraction computed radiography (CR) of the chest and the ability of soft-copy images to detect low-contrast simulated pulmonary nodules. Conventional and bone-subtracted CR images of 25 chest phantom image sets with a low-contrast nylon nodule and 25 without a nodule were interpreted by 12 observers (6 radiologists, 6 chest physicians) who rated each on a continuous confidence scale and marked the position of the nodule if one was present. Hard-copy images were 7 x 7-inch laser-printed CR films, and soft-copy images were displayed on a 21-inch noninterlaced color CRT monitor with an optimized dynamic range. Soft-copy images were adjusted to the same size as hard-copy images and were viewed under darkened illumination in the reading room. No significant differences were found between hard- and soft-copy images. In conclusion, the soft-copy images were found to be useful in detecting low-contrast simulated pulmonary nodules. (+info)
Image compression and chest radiograph interpretation: image perception comparison between uncompressed chest radiographs and chest radiographs stored using 10:1 JPEG compression.
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We have assessed the effect of 10:1 lossy (JPEG) compression on six board-certified radiologists' ability to detect three commonly seen abnormalities on chest radiographs. The study radiographs included 150 chest radiographs with one of four diagnoses: normal (n = 101), pulmonary nodule (n = 19), interstitial lung disease (n = 19), and pneumothorax (n = 11). Before compression, these images were printed on laser film and interpreted in a blinded fashion by six radiologists. Following an 8-week interval, the images were reinterpreted on an image display workstation after undergoing 10:1 lossy compression. The results for the compressed images were compared with those of the uncompressed images using receiver operating characteristic (ROC) analyses. For five of six readers, the diagnostic accuracy was higher for the uncompressed images than for the compressed images, but the difference was not significant (P > .1111). Combined readings for the uncompressed images were also more accurate when compared with the compressed images, but this difference was also not significant (P = .1430). The sensitivity, specificity, and accuracy values were 81.5%, 89.2%, and 86.7% for the compressed images, respectively, as compared with 78.9%, 94.5%, and 89.3% for the uncompressed images. There was no correlation between the readers' accuracy and their experience with soft-copy interpretation; the extent of radiographic interpretation experience had no correlation with overall interpretation accuracy. In conclusion, five of six radiologists had a higher diagnostic accuracy when interpreting uncompressed chest radiographs versus the same images modified by 10:1 lossy compression, but this difference was not statistically significant. (+info)
Physiological and radiological characterisation of patients diagnosed with chronic obstructive pulmonary disease in primary care.
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BACKGROUND: Chronic obstructive pulmonary disease (COPD) is common although often poorly characterised, particularly in primary care. However, application of guidelines to the management of such patients needs a clear understanding of the phenotype. In particular, the British guidelines for the management of COPD recommend that the diagnosis is based on appropriate symptoms and evidence of airflow obstruction as determined by a forced expiratory volume in one second (FEV(1)) of <80% of the predicted value and an FEV(1)/VC ratio of <70%. METHODS: A study was undertaken of 110 patients aged 40-80 years who had presented to their general practitioner with an acute exacerbation of COPD. The episode was treated at home and, when patients had recovered to the stable state (two months later), they were characterised by full lung function tests and a high resolution computed tomographic (HRCT) scan of the chest. RESULTS: There was a wide range of impairment of FEV(1) which was in the normal range (>/=80%) in 30%, mildly impaired (60-79%) in 18%, moderately impaired (40-59%) in 33%, and severely impaired (<40%) in 19% of patients. A reduced FEV(1)/VC ratio was present in all patients with an FEV(1) of <80% predicted but also in 41% of those with an FEV(1) of >/=80% predicted. Only 5% of patients had a substantial bronchodilator response suggesting a diagnosis of asthma. Emphysema was present in 51% of patients and confined to the upper lobes in most (73% of these patients). HRCT evidence of bronchiectasis was noted in 29% of patients and was predominantly tubular; most (81%) were current or ex-smokers. A solitary pulmonary nodule was seen on 9% of scans and unsuspected lung malignancy was diagnosed in two patients. CONCLUSIONS: This study confirms that COPD in primary care is a heterogeneous condition. Some patients do not fulfil the proposed diagnostic criteria with FEV(1) of >/=80% predicted but they may nevertheless have airflow obstruction. Bronchiectasis is common in this group of patients, as is unsuspected malignancy. These findings should be considered when developing recommendations for the investigation and management of COPD in the community. (+info)
Percutaneous image-guided biopsy of lung nodules in the assessment of disease activity in Wegener's granulomatosis.
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OBJECTIVE: In patients with known Wegener's granulomatosis (WG) and persistent chest radiographic abnormalities, assessment for disease activity is often difficult, prompting the need for histological diagnosis to determine appropriate treatment. Here we report the use of automated image-guided core needle biopsy of pulmonary lesions for the assessment of disease activity in WG, rather than for primary diagnosis. METHODS: Image-guided percutaneous core needle biopsy was performed on five occasions in four patients with thoracic WG and persistent radiographic abnormalities of the chest. Clinical features, indication for biopsy, radiographic abnormalities and pathological findings were recorded. RESULTS: Adequate pathological specimens were obtained, allowing exclusion of infection and tumour. Active chronic inflammation with or without vasculitis was demonstrated in each case, indicating the need for further immunosuppressive therapy. A small pneumothorax following biopsy in one case required no treatment. Follow-up chest imaging revealed a reduction in the extent of thoracic disease following therapy in all cases. CONCLUSIONS: The safety and diagnostic accuracy of image-guided core biopsy of thoracic lesions makes it a useful tool in the assessment of disease activity in WG patients with persistent chest radiographic lesions. (+info)