Chest radiography for predicting the cause of febrile illness among inpatients in Moshi, Tanzania.

AIM: To describe chest radiographic abnormalities and assess their usefulness for predicting causes of fever in a resource-limited setting. MATERIALS AND METHODS: Febrile patients were enrolled in Moshi, Tanzania, and chest radiographs were evaluated by radiologists in Tanzania and the United States. Radiologists were blinded to the results of extensive laboratory evaluations to determine the cause of fever. RESULTS: Of 870 febrile patients, 515 (59.2%) had a chest radiograph available; including 268 (66.5%) of the adolescents and adults, the remainder were infants and children. One hundred and nineteen (44.4%) adults and 51 (20.6%) children were human immunodeficiency virus (HIV)-infected. Among adults, radiographic abnormalities were present in 139 (51.9%), including 77 (28.7%) with homogeneous and heterogeneous lung opacities, 26 (9.7%) with lung nodules, 25 (9.3%) with pleural effusion, 23 (8.6%) with cardiomegaly, and 13 (4.9%) with lymphadenopathy. Among children, radiographic abnormalities were present in 87 (35.2%), including 76 (30.8%) with homogeneous and heterogeneous lung opacities and six (2.4%) with lymphadenopathy. Among adolescents and adults, the presence of opacities was predictive of Streptococcus pneumoniae and Coxiella burnetii, whereas the presence of pulmonary nodules was predictive of Histoplasma capsulatum and Cryptococcus neoformans. CONCLUSIONS: Chest radiograph abnormalities among febrile inpatients are common in northern Tanzania. Chest radiography is a useful adjunct for establishing an aetiologic diagnosis of febrile illness and may provide useful information for patient management, in particular for pneumococcal disease, Q fever, and fungal infections.

The value of end-of-treatment chest radiograph in predicting pulmonary tuberculosis relapse.

SETTING: Patients with cavitary pulmonary tuberculosis (TB) on baseline chest radiograph (CXR) who remain culture-positive after 8 weeks of treatment are at high risk of relapse. The role of end-of-treatment (EOT) CXR in predicting relapse is unclear. OBJECTIVE: To determine whether EOT CXR independently predicts TB relapse. DESIGN: We conducted a secondary analysis of a randomized trial of intermittent treatment using rifapentine in the continuation phase of TB treatment among 1004 human immunodeficiency virus seronegative adults with culture-proven pulmonary TB. RESULTS: Relapse occurred in 17.3% of subjects with persistent cavity on EOT CXR, in 7.6% of subjects with a cavity that resolved by EOT, and 2.5% (P=0.002 for trend) of subjects who never had a cavity. In multivariable analysis, patients with persistent cavity on EOT CXR were significantly more likely to relapse than patients with no cavity on baseline or 2-month CXR (hazard ratio [HR] 4.22, 95%CI 2.00-8.91), and were more likely to relapse than subjects whose early cavity had resolved by EOT CXR (HR 1.92, 95%CI 1.09-3.39). CONCLUSION: A persistent cavity after 6 months of TB treatment was independently associated with disease relapse after controlling for other variables. EOT CXR may help predict those likely to relapse.

Stage distribution in patients with a small (< or = 3 cm) primary nonsmall cell lung carcinoma. Implication for lung carcinoma screening.

BACKGROUND: Recently, there has been increased interest in the use of computed tomography (CT) for lung carcinoma screening. For this technique to be effective, small tumors must be detected at an earlier stage than large lesions. However, to the authors's knowledge, the relationship between the size of small primary (< or = 3 cm) neoplasms and disease stage at presentation has never been established clearly. The current study was performed to determine whether smaller lesions indeed have an earlier stage distribution compared with larger tumors. METHODS: The Duke University Medical Center Tumor Registry identified 620 patients (261 women and 359 men, with a mean age of 67 years) who presented with pathologically proven primary nonsmall cell lung carcinomas measuring < or = 3 cm between 1980-1999. Surgical, pathologic, and imaging information was reviewed retrospectively to confirm the size of the lesion and the disease stage at the time of presentation. The distribution of tumor size within each stage and the distribution of disease stage according to tumor size were determined. RESULTS: Tumors occurring in patients with TNM Stage IIIB disease were slightly larger than those found in patients with either more advanced or less advanced disease. However, there was no apparent statistically significant relation between the stage distribution and the size of the primary lesion. CONCLUSIONS: The current study data did not find a statistically significant relation between the size of small primary lung tumors and the distribution of disease stage at the time of presentation. This finding suggests that the detection of small tumors using screening CT may not result in a shift to an earlier disease stage distribution. A reduction in mortality needs to be demonstrated by appropriate clinical trials prior to the initiation of mass CT screening programs.

CT screening for lung cancer: not ready for routine practice.

Lung cancer continues to be a major worldwide health problem. Multiple strategies are being explored in an attempt to reduce lung cancer mortality, including a renewed interest in screening. Multiple low-dose spiral computed tomography (CT) trials have been proposed, as proponents predict that small nodules will represent early-stage disease and detecting them will ultimately translate into improvements in outcomes. At this time, however, only prevalence-screening data are available, and it remains to be seen if CT will truly reduce mortality. The appropriate hypothesis-driven studies still must be performed and the results carefully analyzed before CT screening for lung cancer can be accepted as the standard of care.

Correlation of FDG-PET imaging with Glut-1 and Glut-3 expression in early-stage non-small cell lung cancer.

PURPOSE: To correlate FDG activity on PET with the expression of glucose transporter proteins Glut-1 and Glut-3 in patients with early stage non-small cell lung cancer (NSCLC). METHODS: Over a 5 year period, all patients with a PET scan and clinical stage I NSCLC underwent an immunohistochemical analysis of their tumor for Glut-1 and Glut-3 expression. The amount of FDG uptake in the primary lesion was measured by a standardized uptake ratio (SUR) and correlated with immunohistochemical results. RESULTS: Seventy-three patients with a mean age of 66 years had clinical stage I disease. The final pathologic stage showed 64 patients with stage IA/B disease, eight with stage IIA disease, and one patient with pathologic stage IIIA (T1N2) disease. Glut-1 transporter expression was significantly higher than Glut-3 (P<0.0001), and although there was some association between the SUR and Glut-1 (P=0.085) and SUR and Glut-3 (P=0.074) expression, this did not reach statistical significance. CONCLUSIONS: Glut-1 and Glut-3 transporter expression did not demonstrate a statistically significant correlation with FDG uptake in potentially resectable lung cancer. It appears that these transporters alone do not affect the variation in FDG activity in early stage NSCLC.

Integration of peripheral blood biomarkers with computed tomography to differentiate benign from malignant pulmonary opacities.

Our purpose was to determine whether peripheral blood biomarkers MUC1 and CK19 could be used to complement imaging studies in differentiating benign from malignant indeterminate pulmonary nodules or masses detected on computed tomography CT. One hundred and eighteen patients had a thoracic CT and blood drawn for tumor marker reverse transcriptase-polymerase chain reaction analysis. Thirty-five of the 118 patients had an indeterminate pulmonary nodular opacity on CT, and the findings then were correlated with the reverse transcriptase-polymerase chain reaction results. The sensitivity and specificity for the markers in determining malignancy was calculated. Thirteen of the 35 opacities on CT proved to be benign, and 22 proved to be lung cancer. Among the patients with indeterminate pulmonary abnormalities, polymorphic epithelial mucin protein 1 had a sensitivity and specificity for lung cancer of 100% and 46%, respectively. Cytokeratin 19 had a sensitivity and specificity for lung cancer of 95% and 8%, respectively. These preliminary data showed that serum biomarkers polymorphic epithelial mucin protein 1 and cytokeratin 19 were not specific for lung cancer, although patients with an indeterminate pulmonary abnormality and negative markers were unlikely to have lung cancer. Integration of imaging studies with the appropriate biomarkers may prove useful in evaluating indeterminate pulmonary nodules or masses.

Malignant peripheral nerve sheath tumors of intrathoracic vagus nerve.

The authors report two cases of malignant peripheral nerve sheath tumors arising from the vagus nerve in the mediastinum in patients who had no stigmata of neurofibromatosis (von Recklinghausen's disease). Computed tomography showed homogeneous soft tissue masses, with minimal calcification seen in one patient. T2-weighted magnetic resonance images showed regions of low signal intensity caused by a dense cellular population.

Identification of small lung nodules at autopsy: implications for lung cancer screening and overdiagnosis bias.

PURPOSE: Unsuspected cases of lung cancer are reported to be uncommon in autopsy series, and these data have been used to suggest that indolent tumors are rare and that overdiagnosis bias is not an important factor in lung cancer screening. The purpose of this study was to determine if a retrospective autopsy review is indeed accurate in identifying all small lung nodules on CT, and thus provide a true estimate of unsuspected lung tumors. MATERIALS AND METHODS: We identified all 1047 patients who had an autopsy at our institution from 1994 to 1998. We then reviewed the patients radiology records and found 187 patients with a thoracic CT within 2 months of the postmortem examination. All 187 CT reports were reviewed in order to identify patients with at least one pulmonary nodule. CT studies with reports that described a nodule(s) were then re-reviewed to confirm presence and location of the nodule(s). The CT findings were than compared to the autopsy report to determine if the postmortem examination indeed found the nodule(s). RESULTS: 28 autopsy patients had at least one pulmonary nodule identified on their thoracic CT no more than 2 months before death. Nineteen patients (68%) had nodule(s) recorded on the autopsy report, two ( approximately 10%) of which proved to have undiagnosed squamous cell carcinoma. Nine patients (22%) had no mention of pulmonary nodules seen on the CT recorded on their autopsy report. CONCLUSIONS: This study suggests autopsies do not identify all small pulmonary nodules found at CT. The true incidence of clinically insignificant lung cancer is thus uncertain, and overdiagnosis bias in lung cancer screening may be more important than previously recognized.

Radiographic findings in patients with acute respiratory distress syndrome.

Since its description in 1967, acute respiratory distress syndrome (ARDS) has become a widely recognized, if somewhat imperfectly understood, entity. This article reviews the imaging characteristics of ARDS as demonstrated on plain chest radiography, CT scan, radionuclide imaging, and MR imaging. The abnormalities displayed on these modalities are well understood even though there may be some dispute as to their relative importance in diagnosing and managing patients.

Pulmonary drug toxicity: radiologic and pathologic manifestations.

Pulmonary drug toxicity is increasingly being diagnosed as a cause of acute and chronic lung disease. Numerous agents including cytotoxic and noncytotoxic drugs have the potential to cause pulmonary toxicity. The clinical and radiologic manifestations of these drugs generally reflect the underlying histopathologic processes and include diffuse alveolar damage (DAD), nonspecific interstitial pneumonia (NSIP), bronchiolitis obliterans organizing pneumonia (BOOP), eosinophilic pneumonia, obliterative bronchiolitis, pulmonary hemorrhage, edema, hypertension, or veno-occlusive disease. DAD is a common manifestation of pulmonary drug toxicity and is frequently caused by cytotoxic drugs, especially cyclophosphamide, bleomycin, and carmustine. It manifests radiographically as bilateral hetero- or homogeneous opacities usually in the mid and lower lungs and on high-resolution computed tomographic (CT) scans as scattered or diffuse areas of ground-glass opacity. NSIP occurs most commonly as a manifestation of carmustine toxicity or of toxicity from noncytotoxic drugs such as amidarone. At radiography, it appears as diffuse areas of heterogeneous opacity, whereas early CT scans show diffuse ground-glass opacity and late CT scans show fibrosis in a basal distribution. BOOP, which is commonly caused by bleomycin and cyclophosphamide (as well as gold salts and methotrexate), appears on radiographs as hetero- and homogeneous peripheral opacities in both upper and lower lobes and on CT scans as poorly defined nodular consolidation, centrilobular nodules, and bronchial dilatation. Knowledge of these manifestations and of the drugs most frequently involved can facilitate diagnosis and institution of appropriate treatment.

FDG PET of pleural effusions in patients with non-small cell lung cancer.

OBJECTIVE: We determined the ability of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) to differentiate benign and malignant pleural effusions in patients with non-small cell lung cancer. MATERIALS AND METHODS: Over a 6-year period, we reviewed all patients with primary non-small cell lung cancer and a pleural effusion on staging CT who underwent FDG PET. We examined 25 patients (18 men and seven women; age range, 37-86 years; mean age, 65 years). FDG PET revealed positive findings if pleural activity was greater than background mediastinal activity; FDG PET revealed negative findings if pleural activity was the same as or less than background mediastinal activity. Results of FDG PET were correlated with pathologic diagnosis determined with thoracentesis or pleural biopsy. RESULTS: All patients had effusions on the same side as the primary tumor. Twenty-two patients had a malignant pleural effusion confirmed with thoracentesis (n = 19) or biopsy (n = 3). FDG PET revealed positive findings in 21 patients and negative findings in one. Three patients had no evidence of malignancy in the pleural space determined with cytologic findings (n = 2) or biopsy results (n = 1). FDG PET uptake revealed positive findings in one of these patients and negative findings in two. Therefore, of 22 patients with positive findings on FDG PET, 21 had pleural metastases, and of three patients with negative findings on FDG PET, one had metastases. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of FDG PET for detecting pleural metastases were 95%, 67%, 95%, 67%, and 92%, respectively. CONCLUSION: This study suggests that FDG PET may be useful in improving staging evaluation in patients with non-small cell lung cancer and a pleural effusion. Increased pleural FDG uptake usually indicates pleural metastases; however, because the number of benign effusions studied was small, the relevance of negative findings on FDG PET in this setting is uncertain.

Correlation of tumor size and survival in patients with stage IA non-small cell lung cancer.

OBJECTIVE: The purpose of this study was to determine the relationship between tumor size and survival in patients with stage IA non-small cell lung cancer (non-small cell lung cancer; ie, lesions < 3 cm). METHOD: Five hundred ten patients with pathologic stage IA (T1N0M0) non-small cell lung cancer were identified from our tumor registry over an 18-year period (from 1981 to 1999). There were 285 men and 225 women, with a mean age of 63 years (range, 31 to 90 years). The Cox proportional model was used to examine the effect on survival. Tumor size was incorporated into the model as a linear effect and as categorical variables. The Kaplan-Meier product limit estimator was used to graphically display the relationship between the tumor size and survival. RESULTS: The Cox proportional hazards model did not show a statistically significant relationship between tumor size and survival (p = 0.701) as a linear effect. Tumor size was then categorized into quartiles, and again there was no statistically significant difference in survival between groups (p = 0.597). Tumor size was also categorized into deciles, and there was no statistical relationship between tumor size and survival (p = 0.674). CONCLUSIONS: This study confirms stratifying patients with stage IA non-small cell lung cancer in the same TNM classification, given no apparent difference in survival. Unfortunately, these data caution that improved small nodule detection with screening CT may not significantly improve lung cancer mortality. The appropriate prospective randomized trial appears warranted.

Management of malignant pleural effusions and pneumothorax.

Pneumothorax may occur spontaneously or result from underlying lung disease or as a complication of interventional thoracic procedures. Percutaneous catheter placement enables safe and effective drainage of pneumothoraces with rapid relief of symptoms and restoration of vital capacity and oxygenation.

Spiral CT for pulmonary embolism.

Radiologic imaging for pulmonary embolism has been problematic. Ventilation perfusion scanning is frequently inconclusive; pulmonary angiography has been traditionally underused. Now spiral computed tomographic (CT) angiography provides a readily available, noninvasive test for pulmonary embolism. The accuracy of this examination is exceedingly high, so it should become the first-line test for pulmonary embolism. Recent investigations reveal a high negative predictive value for spiral CT, further proving its value. In addition, spiral CT provides an alternative diagnosis in a high percentage of patients. This article reviews current literature regarding the sensitivity, specificity, reliability, consistency, and cost-effectiveness of spiral CT.