Faculty Bibliography

PURPOSE: An increased incidence of sarcoidosis has been demonstrated in firefighters, supporting the concern that occupational/environmental exposure may pose an etiologic risk factor. This incidence increased further after September 11, 2001 following exposure to World Trade Center (WTC) dust and gases. We review computed tomography (CT) features in this population, comparing the range of findings and physiological correlates with those typically reported in unexposed individuals with pulmonary sarcoidosis. MATERIALS AND METHODS: With CT imaging we retrospectively identified 46 patients with WTC-related sarcoidosis, between March 18, 2002 and April 5, 2014. Scans were independently reviewed by 2 dedicated thoracic radiologists and assessed for disease patterns and correlation with pulmonary functions. RESULTS: The majority (37/46; 80%) had symmetric mediastinal and hilar lymphadenopathy. Similarly, most (38/46; 83%) had perilymphatic nodules. Foci of ill-defined ground glass attenuation were present in 6 (13%). Coalescent nodularity was present in 15 (33%). Only 3 (7%) had parenchymal reticulation. A mixed pattern of lung findings was present in 21 (46%). When all forms of parenchymal disease were scored by zonal distribution, 21 (46%) had parenchymal disease predominantly involving mid and upper lungs; 11/46 (24%) had a random distribution without zonal predominance; 6/46 (13%) demonstrated atypical lower zone predominance. Whereas 15/46 (33%) had obstructive airways disease on pulmonary function tests, there were no CT findings that were predictive of obstructive airways disease. CONCLUSIONS: The majority of cases of WTC-related sarcoidosis demonstrated typical radiographic appearances of sarcoidosis, with symmetric hilar and mediastinal lymphadenopathy and mid to upper lung perilymphatic nodules; these findings were consistent with other previously reported cases of sarcoid-like granulomatous disease in association with various alternate underlying etiologies. There was no correlation between disease patterns or extent on CT and pulmonary function testing, likely at least in part due to the overall mild extent of disease in this population.

BACKGROUND: Clinical TNM staging is based on a qualitative assessment of features defining T descriptors and has been found suboptimal for predicting prognosis of patients with MPM. Previous work suggests that volumetric CT (VOLCT) is prognostic and, if found practical and reproducible, could improve clinical MPM classification.background METHODS: Six North American institutions electronically submitted clinical, pathologic and imaging data on patients with stages I-IV MPM to an established multicenter database and biostatistical center (BC). Two reference radiologists, blinded to clinical data, independently reviewed scans, calculated clinical TNM stage by standard criteria, performed semi-automated tumor volume calculations using commercially available software, and submitted the findings to BC. Study endpoints included feasibility of a multi-institutional VOLCT network, concordance of independent VOLCT assessments and association of VOLCT with pathologic T classification. RESULTS: Of 164 submitted cases, 129 were evaluated by both reference radiologists. Discordant clinical staging of most cases confirmed the inadequacy of current criteria. The overall correlation between VOLCT estimates was good (Spearman Corr. = 0.822), but some were significantly discordant. Root-cause analysis of the most discordant estimates identified four common sources of variability. Despite these limitations, median tumor volume estimates were similar within subgroups of cases representing each pathological T descriptor, and increased monotonically for each reference pathologist with increasing pathological T status.results CONCLUSIONS: Good correlation between VOLCT estimates obtained for most cases reviewed by two independent radiologists, and qualitative association of VOLCT with pathological T status combine to encourage further study. Identified sources of user error will inform design of a follow-on prospective trial to more formally assess inter-observer variability of VOLCT and its potential contribution to clinical MPM staging. CONCLUSION:

This article proposes codes for the primary tumor categories of adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA), and a uniform way to measure tumor size in part-solid tumors for the 8th edition of the tumor, node and metastasis (TNM) classification of lung cancer. In 2011 new entities of AIS, MIA and lepidic predominant adenocarcinoma (LPA) were defined and were later incorporated in the 2015 World Health Organization classification of lung cancer. To fit these entities into the T component of the staging system the Tis category is proposed for AIS, specifying Tis (AIS) if it is to be distinguished from squamous cell carcinoma in situ to be designated Tis (SCIS). We also propose MIA to be classified as T1mi. Furthermore, the use of the invasive size for T-descriptor size follows a recommendation made in three editions of the UICC TNM Supplement since 2003. For tumor size, the greatest dimension should be reported both clinically and pathologically. In nonmucinous lung adenocarcinomas, the computed tomography (CT) findings of ground glass versus solid opacities tend to correspond respectively to lepidic versus invasive patterns seen pathologically. However, this correlation is not absolute; so when CT features suggest nonmucinous AIS, MIA and LPA, the suspected diagnosis and clinical staging, should be regarded as a preliminary assessment that is subject to revision after pathologic evaluation of resected specimens. The ability to predict invasive versus non-invasive size based on solid versus ground glass components is not applicable to mucinous AIS, MIA or invasive mucinous adenocarcinomas because they generally show solid nodules or consolidation on CT.

Purpose To identify the ability of computer-derived three-dimensional (3D) computed tomographic (CT) segmentation techniques to help differentiate lung adenocarcinoma subtypes. Materials and Methods This study had institutional research board approval and was HIPAA compliant. Pathologically classified resected lung adenocarcinomas (n = 23) with thin-section CT data were identified. Two readers independently placed over-inclusive volumes around nodules from which automated computer measurements were generated: mass (total mass) and volume (total volume) of the nodule and of any solid portion, in addition to the solid percentage of the nodule volume (percentage solid volume) or mass (percentage solid mass). Interobserver agreement and differences in measurements among pathologic entities were evaluated by using t tests. A multinomial logistic regression model was used to differentiate the probability of three diagnoses: invasive non-lepidic-predominant adenocarcinoma (INV), lepidic-predominant adenocarcinoma (LPA), and adenocarcinoma in situ (AIS)/minimally invasive adenocarcinoma (MIA). Results Mean percentage solid volume of INV was 35.4% (95% confidence interval [CI]: 26.2%, 44.5%)-higher than the 14.5% (95% CI: 10.3%, 18.7%) for LPA (P = .002). Mean percentage solid volume of AIS/MIA was 8.2% (95% CI: 2.7%, 13.7%) and had a trend toward being lower than that for LPA (P = .051). Accuracy of the model based on total volume and percentage solid volume was 73.2%; accuracy of the model based on total mass and percentage solid mass was 75.6%. Conclusion Computer-assisted 3D measurement of nodules at CT had good reproducibility and helped differentiate among subtypes of lung adenocarcinoma. (c) RSNA, 2016.

Purpose To examine the factors that affect inter- and intraobserver agreement for pulmonary nodule type classification on low-radiation-dose computed tomographic (CT) images, and their potential effect on patient management. Materials and Methods Nodules (n = 160) were randomly selected from the Dutch-Belgian Lung Cancer Screening Trial cohort, with equal numbers of nodule types and similar sizes. Nodules were scored by eight radiologists by using morphologic categories proposed by the Fleischner Society guidelines for management of pulmonary nodules as solid, part solid with a solid component smaller than 5 mm, part solid with a solid component 5 mm or larger, or pure ground glass. Inter- and intraobserver agreement was analyzed by using Cohen kappa statistics. Multivariate analysis of variance was performed to assess the effect of nodule characteristics and image quality on observer disagreement. Effect on nodule management was estimated by differentiating CT follow-up for ground-glass nodules, solid nodules 8 mm or smaller, and part-solid nodules smaller than 5 mm from immediate diagnostic work-up for solid nodules larger than 8 mm and part-solid nodules 5 mm or greater. Results Pair-wise inter- and intraobserver agreement was moderate (mean kappa, 0.51 [95% confidence interval, 0.30, 0.68] and 0.57 [95% confidence interval, 0.47, 0.71]). Categorization as part-solid nodules and location in the upper lobe significantly reduced observer agreement (P = .012 and P < .001, respectively). By considering all possible reading pairs (28 possible combinations of observer pairs x 160 nodules = 4480 possible agreements or disagreements), a discordant nodule classification was found in 36.4% (1630 of 4480), related to presence or size of a solid component in 88.7% (1446 of 1630). Two-thirds of these discrepant readings (1061 of 1630) would have potentially resulted in different nodule management. Conclusion There is moderate inter- and intraobserver agreement for nodule classification by using current recommendations for low-radiation-dose CT examinations of the chest. Discrepancies in nodule categorization were mainly caused by disagreement on the size and presence of a solid component, which may lead to different management in the majority of cases with such discrepancies. ((c)) RSNA, 2015.

A wide variety of pathologic processes, both benign and malignant, affect the central airways. These processes may be classified into 4 distinct groups: anatomic variants, lesions that result in focal or diffuse airway narrowing, and those that result in multinodular airway disorder. Key to the accurate assessment of the central airways is meticulous imaging technique, especially the routine acquisition of contiguous high-resolution, 1-mm to 1.5-mm images. These images enable high-definition axial, coronal, and sagittal reconstructions, as well as advanced imaging techniques, including minimum intensity projection images and virtual bronchoscopy. Current indications most commonly include patients presenting with signs and symptoms of possible central airway obstruction, with or without hemoptysis. In addition to diagnosing airway abnormalities, computed tomography (CT) also serves a critical complementary role to current bronchoscopic techniques for both diagnosing and treating airway lesions. Advantages of CT include noninvasive visualization of the extraluminal extent of lesions, as well as visualization of airways distal to central airways obstructions. As discussed and illustrated later, thorough knowledge of current bronchoscopic approaches to central airway disease is essential for optimal correlative CT interpretation.

Lung cancer screening with a low-dose chest CT scan can result in more benefit than harm when performed in settings committed to developing and maintaining high-quality programs. This project aimed to identify the components of screening that should be a part of all lung cancer screening programs. To do so, committees with expertise in lung cancer screening were assembled by the Thoracic Oncology Network of the American College of Chest Physicians (CHEST) and the Thoracic Oncology Assembly of the American Thoracic Society (ATS). Lung cancer program components were derived from evidence-based reviews of lung cancer screening and supplemented by expert opinion. This statement was developed and modified based on iterative feedback of the committees. Nine essential components of a lung cancer screening program were identified. Within these components 21 Policy Statements were developed and translated into criteria that could be used to assess the qualification of a program as a screening facility. Two additional Policy Statements related to the need for multisociety governance of lung cancer screening were developed. High-quality lung cancer screening programs can be developed within the presented framework of nine essential program components outlined by our committees. The statement was developed, reviewed, and formally approved by the leadership of CHEST and the ATS. It was subsequently endorsed by the American Association of Throacic Surgery, American Cancer Society, and the American Society of Preventive Oncology.

Rationale: Early COPD is characterized by inflammation leading to lung destruction. Recent data supports that enrichment of the lung microbiome with supraglottic characteristic taxa (SCT) is associated with inflammation. We hypothesize that in subjects with early COPD, areas at higher risk for microaspiration (right) or with greater degree of parenchymal abnormalities will be enriched with SCT or potential pathogenic taxa (PPT) compared to their contralateral lung segment. Methods: Subjects with early emphysema were enrolled for research bronchoscopy from the NYU/EDRN cohort. An independent radiologist semiquantitatively assessed all Chest CT scans: six-point score based on the presence of parenchymal damage in three zones (upper, middle, and lower). Broncho-alveolar lavages (BAL) were obtained from the right middle lobe and lingula segments. Sequencing 16S rDNA performed with 454 pyrosequence. Results: A total of 15 subjects with early COPD were studied. CT scans demonstrated n=7 with normal lower zones and n=8 with symmetrical or asymmetrical emphysema in the lower zones (p=ns). We used Wilcoxon paired comparisons to analyze the microbiome in areas of greater degree of parenchymal abnormalities (if asymmetric) or right compared to the contralateral lung segment. Data showed that the areas of greater abnormalities or right were associated with increased relative abundance (RA) of Haemophilus (RA 0.00170+/-0.002 vs. 0.00084+/-0.001, p=0.04), Neisseria (RA 0.0048+/-0.005 vs. 0.0023+/-0.003, p=0.028), Parvimonas (RA 0.017+/-0.003 vs. 0.0002+/-0.0008, p=0.05), and Serratia (RA 0.0122+/-0.02 vs. 0.0033+/-0.003, p=0.03) compared with the contralateral segment. Streptococcus appeared not to have a predilection for at-risk segments at the genus level. However, at the OTU level, Streptococcus mitis and Streptococcus pneumoniae species were higher in lung segments with more emphysema or right lung segments. Conclusions: Our data shows that areas of greater parenchymal damage or at higher risk for microaspiration (right) are enriched with potentially pathogenic taxa, such as Parvimonas, Neisseria, Haemophilus, Serratia, and Streptococcus. These taxa are known to be in high relative abundance in the oral and supraglottic region. Some of these taxa have been found to be at higher RA after viral infections, suggesting that enrichment of these low relative abundance taxa may play a critical role in disease. However, other supraglottic characteristic taxa such as Prevotella and Veillonella were not increased in these regions. These observations suggest a distinct selection pressure between the upper and lower airway microbiome

Persistent subsolid nodules, part-solid or pure ground-glass attenuation, are associated with primary lung adenocarcinoma, recently redefined by the International Association for the Study of Lung Cancer-American Thoracic Society-European Respiratory Society in 2011 and include newly categorized entities of adenocarcinoma in situ, minimally invasive adenocarcinoma, and lepidic-predominant adenocarcinoma. Awareness of the relationship of the subsolid nodule with adenocarcinoma has emerged in the era of high-resolution multidetector computed tomography (CT). This article highlights the role of noninvasive CT for subsolid nodules with an emphasis on the potential for quantitative measures to predict adenocarcinoma subtypes and their longitudinal behavior. Of particular importance is the knowledge that an increase in solid components on CT is an indication of progression. Continued experience in evaluating quantitative measures in combination with morphologic features, including margin contour, internal architecture, and nodule size, will further aid in guiding crucial decisions pertaining to the use of CT surveillance vs more invasive approaches including biopsy and surgical resection.

Airway stents are increasingly used to treat symptomatic patients with obstructive tracheobronchial diseases who are not amenable to surgical resection or who have poor performance status, precluding them from resection. The most common conditions that are treated with tracheobronchial stents are primary lung cancer and metastatic disease. However, stents have also been used to treat patients with airway stenosis related to a variety of benign conditions, such as tracheobronchomalacia, relapsing polychondritis, postintubation tracheal stenosis, postoperative anastomotic stenosis, and granulomatous diseases. Additionally, airway stents can be used as a barrier method in the management of esophagorespiratory fistulas. Many types of stents are available from different manufacturers. Principally, they are classified as silicone; covered and uncovered metal; or hybrid, which are made of silicone and reinforced by metal rings. The advantages and disadvantages of each type of airway stent are carefully considered when choosing the most appropriate stent for each patient. Multidetector computed tomography plays an important role in determining the cause and assessing the location and extent of airway obstruction. Moreover, it is very accurate in its depiction of complications after airway stent placement. (c)RSNA, 2014.