Faculty Bibliography

Interferons have been used as therapy of both malignant and nonmalignant diseases and commonly in the treatment of hepatitis C virus infection. Although the most commonly encountered side effects of interferon therapy include nonspecific constitutional symptoms, pulmonary involvement is rare. Here, we provide two documented cases of sarcoidosis appearing in patients receiving interferon therapy for hepatitis C infection, because there have only been a few reports of this association. Physicians should be aware of this uncommon yet clinically important complication, because imaging these patients may obviate more invasive procedures

Air trapping is a prominent finding in small airway disease (SAD) of the lungs. To investigate the feasibility of accurate, automated assessment of air-trapping from low-dose CT, we compare visual scoring by expert radiologists to a conventional method of automated assessment as well as two novel methods. The conventional method, the "density mask" method, has been reported to correlate weakly but significantly with visual scoring on normal-dose CT. While we were unable to reproduce these results on our low-dose scans, our two novel methods showed some promise. More study on larger data sets is required to determine the optimal analysis method.

Air trapping is a prominent finding in small airway disease (SAD)of the lungs. To investigate the feasibility of accurate, automated assessment of air-trapping from low-dose CT, we compare visual scoring by expert radiologists to a conventional method of automated assessment as well as two novel methods. The conventional method,the markdensity maskmark method, has been reported to correlateweakly but significantly with visual scoring on normal-dose CT.While we were unable to reproduce these results on our low-dose scans, our two novel methods showed some promise. More study on larger data sets is required to determine the optimal analysis method.

High-resolution CT is accepted as an accurate noninvasive means of diagnosing bronchiectasis. A wide spectrum of abnormalities may be identified at HRCT in patients with airway disease, including various distinctive patterns of bronchiectasis in specific clinical settings, such as ABPA, MAC infection, AIDS, and CF. Characteristic CT findings occasionally suggest a specific diagnosis that may not have been under clinical consideration. HRCT also provides significant clinical use in assessing the degree and extent of airway disease, and allows noninvasive monitoring of disease progression, regression, or response to therapy

BACKGROUND: The Early Lung Cancer Action Project (ELCAP) was designed to evaluate the usefulness of annual computed tomography (CT) screening for lung carcinoma. With the baseline results having been reported previously, the focus of the current study was on the early results of the repeat screenings. METHODS: A cohort of 1000 high-risk individuals was recruited for baseline and annual repeat CT screening. At last follow-up, a total of 1184 annual repeat screenings had been performed. A positive result from the screening test was defined as newly detected, one to six noncalcified pulmonary nodules with interim growth. The diagnostic workup of the individuals was guided by recommendations supplied by the ELCAP investigators to the collaborating clinicians. RESULTS: Of the 1184 repeat CT screenings, the test result was positive in 30 (2.5%). In 2 of these 30 cases, the individual died (of an unrelated cause) before diagnostic workup and the nodule(s) resolved in another 12 individuals. In the remaining 16 individuals, the absence of further growth was documented by repeat CT in 8 individuals and further growth was documented in the remaining 8 individuals. All eight individuals with further nodular growth underwent biopsy and malignancy was diagnosed in seven. Six of these seven malignancies were nonsmall cell carcinomas (five of which were Stage IA and one of which was Stage IIIA) and the one small cell carcinoma was found to be of limited stage. The median size dimension of these malignancies was 8 mm. In another two subjects, symptoms prompted the interim diagnosis of lung carcinoma. Neither of these malignancies was nodule-associated but rather were endobronchial; one was a Stage IIB nonsmall cell carcinoma and the other was a small cell carcinoma of limited stage. CONCLUSIONS: False-positive screening test results are uncommon and usually manageable without biopsy; compared with no screening, such screenings permit diagnosis at substantially earlier and thus more curable stages. Annual repetition of CT screening is sufficient to minimize symptom-prompted interim diagnoses of nodule-associated malignancies.

This consensus statement by the Society of Thoracic Radiology is a summary of the current understanding of low dose computed tomography (CT) for screening for lung cancer. Lung cancer is the most common fatal malignancy in the industrialized world. Unlike the next three most common cancers, screening for lung cancer is not currently recommended by cancer organizations. Improvements in CT technology make lung screening feasible. Early prevalence data indicate that about two-thirds of lung cancers that are detected by CT screening are at an early stage. Other data support the postulate that patients with lung cancers detected at this early stage have better rates of survival. Whether this will translate into an improved disease specific mortality is yet to be demonstrated. The suggested technical protocols, selection criteria, and method of handling the numerous benign nodules that are detected are discussed. It is the consensus of this committee that mass screening for lung cancer with CT is not currently advocated. Suitable subjects who wish to participate should be encouraged to do so in controlled trials, so that the value of CT screening can be ascertained as soon as possible.

PURPOSE: The Early Lung Cancer Action Project (ELCAP) is designed to evaluate baseline and annual repeat screening by low radiation dose computed tomography (low-dose CT) in persons at high-risk for lung cancer. METHODS: Since starting in 1993, the ELCAP has enrolled 1,000 asymptomatic persons, 60 years of age or older, with at least 10 pack-years (1 pack per day for 10 years, or 2 packs per day for 5 years) of cigarette smoking, no prior cancer, and medically fit to undergo thoracic surgery. After a structured interview and informed consent, baseline chest radiographs and low-dose CT were obtained on each subject. The diagnostic work-up of screen-detected noncalcified pulmonary nodules (NCN) was guided by ELCAP recommendations which included short-term high-resolution CT follow-up for the smallest nodules. Baseline RESULTS: On low-dose CT at baseline compared to chest radiography, NCN were detected three times as commonly (23% versus 7%), malignancies four times as commonly (2.7% versus 0.7%), and stage I malignancies six times as commonly (2.3% versus 0.4%). Of the 27 CT-detected cancers, 96% (26/27) were resectable; 85% (23/27) were stage I, and 83% (19 of the 23 stage I) were not seen on chest radiography. Following the ELCAP recommendations, biopsies were performed on 28 of the 233 subjects with NCN; 27 had a malignant and one a benign NCN. Another three individuals underwent biopsy outside of the ELCAP recommendations; all had benign NCNS: No one had thoracotomy for a benign nodule. CONCLUSION: Baseline CT screening for lung cancer provides for detecting the disease at earlier and presumably more commonly curable stages in a cost-effective manner.

Computed Tomography (CT) imaging provides a very promising technology for lung cancer detection and treatment. The newest multi-slice CT machines provide high-resolution scans quickly enough that the entire lung volume may be covered in a single breath-hold, and at a low enough radiation dose to make it practical for screening. However, the large amounts of data obtained by these machines present formidable challenges to physicians. A typical scan with slices taken 1 mm apart may have 300 or more image slices. If CT lung cancer screening becomes widespread, there will be tremendous demand for such examinations. Clearly, some sort of computer assistance will be highly beneficial to physicians in coping with such large amounts of data. We present a real time system for interactive assistance in diagnosing, monitoring, and measuring lung nodules in CT images. This interactive system allows physicians to incorporate their knowledge with the computer's ability to perform rapid computations, in order to improve decision-making about diagnosis and treatment. This system may allow for a more efficient workflow, and enhance the acceptance of Computer-Aided Diagnosis

We report an illustrative case of advanced 'hut lung,' or domestically acquired particulate lung disease (DAPLD), in a recently emigrated nonsmoking Bangladeshi woman with a history of 171 hour-years of exposure to biomass smoke. She presented with symptoms of chronic cough, dyspnea, and early parenchymal lung disease. High-resolution computed tomography (CT) of the chest demonstrated numerous 2- to 3-mm nodules, sparing the pleural surface. To our knowledge, this is the first such report of CT findings in the literature. Bronchoscopy yielded typical anthracotic plaques and diffuse anthracosis with interstitial inflammation on histopathologic examination of biopsy specimens. DAPLD is potentially the largest environmentally attributable disorder in the world, with an estimated 3 billion people at risk. Caused by the inhalation of particles liberated from the combustion of biomass fuel, DAPLD results in significant morbidity from infancy to adulthood. Clinically, DAPLD manifests a broad range of disorders from chronic bronchitis and dyspnea to advanced interstitial lung disease and malignancy. While a detailed environmental history is essential for making the diagnosis in most individuals, for patients with advanced DAPLD, invasive modalities such as bronchoscopy with transbronchial biopsy and examination of bronchoalveolar lavage fluid help differentiate it from other diseases. Recognition of this syndrome and removal of the patient from the environment is the only treatment. The development of well-controlled interventional trials and the commitment of sufficient resources to educate local populaces and develop alternative fuel sources, stove designs, and ventilation are essential toward reducing the magnitude of DAPLD