Objectives Growing, small, peripheral, pulmonary nodules in patients at high risk for lung cancer lead to requests for video-assisted thoracoscopic (VATS) resection for pathologic diagnosis. The ...purpose of this randomized controlled trial was to determine if preoperative localization using percutaneously placed computed tomography (CT)–guided platinum microcoils decreases the need for thoracotomy or VATS anatomic resection (segmentectomy/lobectomy) for diagnosis. Methods Patients with undiagnosed nodules of 15 mm or less were randomized to either no localization or preoperative microcoil localization. Coils were placed with the distal end deep to the nodule and the superficial end coiled on the visceral pleural surface with subsequent visualization by intraoperative fluoroscopy and VATS. Nodules were removed by VATS wedge excision using endostaplers. The primary outcome was a VATS wedge excision for pathologic diagnosis of the nodule without the need for either thoracotomy or VATS anatomic resection. Results Sixty patients were randomized and 56 underwent surgery between March 2010 and June 2012. Twenty-nine underwent microcoil localization and 27 did not. The baseline characteristics (age, sex, forced expiratory volume in the first second of expiration, nodule size/depth) were similar. The coil group had a higher rate of successful diagnosis with VATS wedge resection alone (27/29 vs 13/27; P < .001), decreased operative time to nodule excision (37 ± 39 vs 100 ± 67 minutes; P < .001), and reduced stapler firings (3.7 ± 2.0 vs 5.9 ± 31; P = .003) with no difference in total costs. Pathologic diagnoses included 14 benign nodules, 32 primary lung malignancies, and 10 metastases. There were no clinically significant complications related to the coil placement or wedge resection. Conclusions Preoperative CT-guided microcoil localization decreases the need for thoracotomy or VATS anatomic resection for the diagnosis of small peripheral pulmonary nodules.
Pulmonary MRI provides structural and quantitative functional images of the lungs without ionizing radiation, but it has had limited clinical use due to low signal intensity from the lung parenchyma. ...The lack of radiation makes pulmonary MRI an ideal modality for pediatric examinations, pregnant women, and patients requiring serial and longitudinal follow-up. Fortunately, recent MRI techniques, including ultrashort echo time and zero echo time, are expanding clinical opportunities for pulmonary MRI. With the use of multicoil parallel acquisitions and acceleration methods, these techniques make pulmonary MRI practical for evaluating lung parenchymal and pulmonary vascular diseases. The purpose of this Fleischner Society position paper is to familiarize radiologists and other interested clinicians with these advances in pulmonary MRI and to stratify the Society recommendations for the clinical use of pulmonary MRI into three categories:
suggested for current clinical use,
promising but requiring further validation or regulatory approval, and
appropriate for research investigations. This position paper also provides recommendations for vendors and infrastructure, identifies methods for hypothesis-driven research, and suggests opportunities for prospective, randomized multicenter trials to investigate and validate lung MRI methods.
Major issues in the implementation of screening for lung cancer by means of low-dose computed tomography (CT) are the definition of a positive result and the management of lung nodules detected on ...the scans. We conducted a population-based prospective study to determine factors predicting the probability that lung nodules detected on the first screening low-dose CT scans are malignant or will be found to be malignant on follow-up.
We analyzed data from two cohorts of participants undergoing low-dose CT screening. The development data set included participants in the Pan-Canadian Early Detection of Lung Cancer Study (PanCan). The validation data set included participants involved in chemoprevention trials at the British Columbia Cancer Agency (BCCA), sponsored by the U.S. National Cancer Institute. The final outcomes of all nodules of any size that were detected on baseline low-dose CT scans were tracked. Parsimonious and fuller multivariable logistic-regression models were prepared to estimate the probability of lung cancer.
In the PanCan data set, 1871 persons had 7008 nodules, of which 102 were malignant, and in the BCCA data set, 1090 persons had 5021 nodules, of which 42 were malignant. Among persons with nodules, the rates of cancer in the two data sets were 5.5% and 3.7%, respectively. Predictors of cancer in the model included older age, female sex, family history of lung cancer, emphysema, larger nodule size, location of the nodule in the upper lobe, part-solid nodule type, lower nodule count, and spiculation. Our final parsimonious and full models showed excellent discrimination and calibration, with areas under the receiver-operating-characteristic curve of more than 0.90, even for nodules that were 10 mm or smaller in the validation set.
Predictive tools based on patient and nodule characteristics can be used to accurately estimate the probability that lung nodules detected on baseline screening low-dose CT scans are malignant. (Funded by the Terry Fox Research Institute and others; ClinicalTrials.gov number, NCT00751660.).
The Fleischner Society Guidelines for management of solid nodules were published in 2005, and separate guidelines for subsolid nodules were issued in 2013. Since then, new information has become ...available; therefore, the guidelines have been revised to reflect current thinking on nodule management. The revised guidelines incorporate several substantive changes that reflect current thinking on the management of small nodules. The minimum threshold size for routine follow-up has been increased, and recommended follow-up intervals are now given as a range rather than as a precise time period to give radiologists, clinicians, and patients greater discretion to accommodate individual risk factors and preferences. The guidelines for solid and subsolid nodules have been combined in one simplified table, and specific recommendations have been included for multiple nodules. These guidelines represent the consensus of the Fleischner Society, and as such, they incorporate the opinions of a multidisciplinary international group of thoracic radiologists, pulmonologists, surgeons, pathologists, and other specialists. Changes from the previous guidelines issued by the Fleischner Society are based on new data and accumulated experience.
RSNA, 2017 Online supplemental material is available for this article. An earlier incorrect version of this article appeared online. This article was corrected on March 13, 2017.
The purpose of this study was to compare the subjective image quality, image noise, and radiation dose of chest CT images reconstructed with a 30% blend of iterative reconstruction and 70% ...conventional filtered back projection (FBP) with those of images generated with 100% FBP.
Clinically indicated chest CT examinations of 292 consecutively registered patients were prospectively alternately assigned to two scanners on which different reconstruction techniques were used: adaptive statistical iterative reconstruction (ASIR) blended with FBP and 100% FBP. Both acquisitions were performed with dose modulation (noise index, 25 for ASIR and 21 for FBP). Patient demographics and habitus were recorded. Two radiologists blinded to the reconstruction algorithm independently scored subjective image quality on a 3-point Likert scale and measured image noise and radiation dose.
Compared with FBP images, ASIR images had significantly lower subjective image quality (p = 0.01), less image noise (p = 0.02), and less radiation dose (p < 0.0001). The CT dose index of the ASIR cohort (11.3 ± 51) was significantly lower than that of the 100% FBP cohort (15.4 ± 6.3) (p < 0.0001). Interobserver agreement on subjective image quality was excellent for both ASIR and FBP (Cronbach α, 0.92, p < 0.0001; Cronbach α, 0.85, p < 0.0001).
In clinically indicated chest CT examinations, ASIR images had better image quality and less image noise at a lower radiation dose than images acquired with a conventional FBP reconstruction algorithm.
The major sites of obstruction in chronic obstructive pulmonary disease (COPD) are small airways (<2 mm in diameter). We wanted to determine whether there was a relationship between small-airway ...obstruction and emphysematous destruction in COPD.
We used multidetector computed tomography (CT) to compare the number of airways measuring 2.0 to 2.5 mm in 78 patients who had various stages of COPD, as judged by scoring on the Global Initiative for Chronic Obstructive Lung Disease (GOLD) scale, in isolated lungs removed from patients with COPD who underwent lung transplantation, and in donor (control) lungs. MicroCT was used to measure the extent of emphysema (mean linear intercept), the number of terminal bronchioles per milliliter of lung volume, and the minimum diameters and cross-sectional areas of terminal bronchioles.
On multidetector CT, in samples from patients with COPD, as compared with control samples, the number of airways measuring 2.0 to 2.5 mm in diameter was reduced in patients with GOLD stage 1 disease (P=0.001), GOLD stage 2 disease (P=0.02), and GOLD stage 3 or 4 disease (P<0.001). MicroCT of isolated samples of lungs removed from patients with GOLD stage 4 disease showed a reduction of 81 to 99.7% in the total cross-sectional area of terminal bronchioles and a reduction of 72 to 89% in the number of terminal bronchioles (P<0.001). A comparison of the number of terminal bronchioles and dimensions at different levels of emphysematous destruction (i.e., an increasing value for the mean linear intercept) showed that the narrowing and loss of terminal bronchioles preceded emphysematous destruction in COPD (P<0.001).
These results show that narrowing and disappearance of small conducting airways before the onset of emphysematous destruction can explain the increased peripheral airway resistance reported in COPD. (Funded by the National Heart, Lung, and Blood Institute and others.).
This paper examines the determinants of firms' public policymaking influence. Using a novel and global database that measures firms' perceived influence over the executive and legislative branches of ...government, a systematic analysis of the firm-, industry-, and country-level determinants, and interrelationships among these determinants of firms' public policymaking influence is undertaken. The empirical results indicate that large firms perceive they have more public policymaking influence than small firms, but these differences are conditioned by the number of industry competitors and the structure of the country political institution environment. Nonmarket strategy implications that follow from this refined understanding are developed and discussed.
Purpose ”“ The purpose of this paper is describe the salience of economic theories and evidence regarding vertical integration in the multichannel audiovisual industry in Brazil. This is especially ...important at this time because Brazilian regulators and legislators are wrestling with the appropriate policy approach toward the industry in Brazil in the wake of the merger of AT&T and Time Warner.
Methodology/approach/design ”“ The paper develops with several approaches. First, to develop context, the paper provides a high-level introduction to the evolution of the audiovisual industry. Second, the paper turns to a more specific assessment of the economic and legal lessons learned from the discussion and debate regarding the AT&T-Time Warner merger in the United States. This discussion draws on economic and legal theory and evidence, both from the published literature as well as from court proceedings to advance understanding of the issues. These foundational sections, in turn, provide a platform for policy insights. In particular, the paper builds upon earlier research on “results-based regulation” to provide guidance for Brazilian regulatory and legislative measures being considered in Brazil.
Findings ”“ The paper concludes that a results-based approach should permit advances in the vertical integration of the audiovisual industry in Brazil. Such an approach necessarily would recognize that the modern evolution toward a more vertically integrated provisioning of audiovisual services is providing numerous consumer benefits while claims of consumer harm have been judged to be speculative. Application of Article 5 of SeAC to the AT&T-TW merger provides no additional consumer protections that are not already part of the merger and would, instead be distinctly anti-consumer.
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