Fleischner Society: Glossary of Terms for Thoracic Imaging.

Members of the Fleischner Society have compiled a glossary of terms for thoracic imaging that replaces previous glossaries published in 1984, 1996, and 2008, respectively. The impetus to update the previous version arose from multiple considerations. These include an awareness that new terms and concepts have emerged, others have become obsolete, and the usage of some terms has either changed or become inconsistent to a degree that warranted a new definition. This latest glossary is focused on terms of clinical importance and on those whose meaning may be perceived as vague or ambiguous. As with previous versions, the aim of the present glossary is to establish standardization of terminology for thoracic radiology and, thereby, to facilitate communications between radiologists and clinicians. Moreover, the present glossary aims to contribute to a more stringent use of terminology, increasingly required for structured reporting and accurate searches in large databases. Compared with the previous version, the number of images (chest radiography and CT) in the current version has substantially increased. The authors hope that this will enhance its educational and practical value. All definitions and images are hyperlinked throughout the text. Click on each figure callout to view corresponding image. © RSNA, 2024 Supplemental material is available for this article. See also the editorials by Bhalla and Powell in this issue.

Trastuzumab Deruxtecan‒Related Interstitial Lung Disease/Pneumonitis: Computed Tomography Imaging Patterns to Guide Diagnosis and Management.

PURPOSE: Trastuzumab deruxtecan (T-DXd) is an antibody-drug conjugate approved for the treatment of several advanced cancers; however, severe or fatal interstitial lung disease/pneumonitis can occur. We characterized the computed tomography (CT) patterns of T-DXd‒related pneumonitis as a marker for its clinical severity. MATERIALS AND METHODS: Ninety patients with advanced cancers who developed T-DXd‒related pneumonitis in two completed single-arm clinical trials were included. Three radiologists independently characterized the CT patterns of pneumonitis at diagnosis, for analyses of those patterns' relationships with clinical severity and pneumonitis outcome. RESULTS: T-DXd‒related pneumonitis most commonly presented with cryptogenic organizing pneumonia (COP) pattern, observed in 65 patients (72%), followed by a newly identified COP/hypersensitivity pneumonitis (HP) pattern (13%), acute interstitial pneumonia (AIP)/acute respiratory distress syndrome (ARDS) pattern (11%), and HP pattern (3%). A subset of cases with COP pattern demonstrated an atypical distribution with upper and peripheral lung involvement (6/65; 9%). CT patterns were associated with Common Terminology Criteria for Adverse Events severity grades of pneumonitis, with the AIP/ARDS pattern having higher grades compared with others (P < .0001). Fatal pneumonitis was more common in the AIP/ARDS pattern than in others (P = .005). The onset of pneumonitis was earlier in the AIP/ARDS pattern compared with others (median time to onset: at 17.9 v 32.7 weeks of therapy; P = .019). Pneumonitis was treated by withholding T-DXd with or without corticosteroids in most patients (78/90; 87%). CONCLUSION: T-DXd‒related pneumonitis most commonly demonstrated a COP pattern, with a subset having an atypical distribution. The AIP/ARDS pattern was indicative of severe, potentially fatal pneumonitis, and requires immediate clinical attention to mitigate serious adverse events.

Early Detection of Lung Cancer Using Small RNAs.

INTRODUCTION: Lung cancer remains the deadliest cancer in the world, and lung cancer survival is heavily dependent on tumor stage at the time of detection. Low-dose computed tomography screening can reduce mortality; however, annual screening is limited by low adherence in the United States of America and still not broadly implemented in Europe. As a result, less than 10% of lung cancers are detected through existing programs. Thus, there is a great need for additional screening tests, such as a blood test, that could be deployed in the primary care setting. METHODS: We prospectively recruited 1384 individuals meeting the National Lung Screening Trial demographic eligibility criteria for lung cancer and collected stabilized whole blood to enable the pipetting-free collection of material, thus minimizing preanalytical noise. Ultra-deep small RNA sequencing (20 million reads per sample) was performed with the addition of a method to remove highly abundant erythroid RNAs, and thus open bandwidth for the detection of less abundant species originating from the plasma or the immune cellular compartment. We used 100 random data splits to train and evaluate an ensemble of logistic regression classifiers using small RNA expression of 943 individuals, discovered an 18-small RNA feature consensus signature (miLung), and validated this signature in an independent cohort (441 individuals). Blood cell sorting and tumor tissue sequencing were performed to deconvolve small RNAs into their source of origin. RESULTS: We generated diagnostic models and report a median receiver-operating characteristic area under the curve of 0.86 (95% confidence interval [CI]: 0.84-0.86) in the discovery cohort and generalized performance of 0.83 in the validation cohort. Diagnostic performance increased in a stage-dependent manner ranging from 0.73 (95% CI: 0.71-0.76) for stage I to 0.90 (95% CI: 0.89-0.90) for stage IV in the discovery cohort and from 0.76 to 0.86 in the validation cohort. We identified a tumor-shed, plasma-bound ribosomal RNA fragment of the L1 stalk as a dominant predictor of lung cancer. The fragment is decreased after surgery with curative intent. In additional experiments, results of dried blood spot collection and sequencing revealed that small RNA analysis could potentially be conducted through home sampling. CONCLUSIONS: These data suggest the potential of a small RNA-based blood test as a viable alternative to low-dose computed tomography screening for early detection of smoking-associated lung cancer.

Pulmonary functional imaging (PFI): A historical review and perspective.

PFI Pulmonary Functional Imaging (PFI) refers to visualization and measurement of ventilation, perfusion, gas flow and exchange as well as biomechanics. In this review, we will highlight the historical development of PFI, describing recent advances and listing the various techniques for PFI offered per modality. Challenges PFI is facing and requirements for PFI from a clinical point of view will be pointed out. Hereby the review is meant as an introduction to PFI.

Early-stage COVID-19 pandemic observations on pulmonary embolism using nationwide multi-institutional data harvesting.

We introduce a multi-institutional data harvesting (MIDH) method for longitudinal observation of medical imaging utilization and reporting. By tracking both large-scale utilization and clinical imaging results data, the MIDH approach is targeted at measuring surrogates for important disease-related observational quantities over time. To quantitatively investigate its clinical applicability, we performed a retrospective multi-institutional study encompassing 13 healthcare systems throughout the United States before and after the 2020 COVID-19 pandemic. Using repurposed software infrastructure of a commercial AI-based image analysis service, we harvested data on medical imaging service requests and radiology reports for 40,037 computed tomography pulmonary angiograms (CTPA) to evaluate for pulmonary embolism (PE). Specifically, we compared two 70-day observational periods, namely (i) a pre-pandemic control period from 11/25/2019 through 2/2/2020, and (ii) a period during the early COVID-19 pandemic from 3/8/2020 through 5/16/2020. Natural language processing (NLP) on final radiology reports served as the ground truth for identifying positive PE cases, where we found an NLP accuracy of 98% for classifying radiology reports as positive or negative for PE based on a manual review of 2,400 radiology reports. Fewer CTPA exams were performed during the early COVID-19 pandemic than during the pre-pandemic period (9806 vs. 12,106). However, the PE positivity rate was significantly higher (11.6 vs. 9.9%, p < 10-4) with an excess of 92 PE cases during the early COVID-19 outbreak, i.e., ~1.3 daily PE cases more than statistically expected. Our results suggest that MIDH can contribute value as an exploratory tool, aiming at a better understanding of pandemic-related effects on healthcare.

Vascular remodeling of the small pulmonary arteries and measures of vascular pruning on computed tomography.

Pulmonary hypertension is characterized histologically by intimal and medial thickening in the small pulmonary arteries, eventually resulting in vascular "pruning." Computed tomography (CT)-based quantification of pruning is associated with clinical measures of pulmonary hypertension, but it is not established whether CT-based pruning correlates with histologic arterial remodeling. Our sample consisted of 138 patients who underwent resection for early-stage lung adenocarcinoma. From histologic sections, we identified small pulmonary arteries and measured the relative area comprising the intima and media (VWA%), with higher VWA% representing greater histologic remodeling. From pre-operative CTs, we used image analysis algorithms to calculate the small vessel volume fraction (BV5/TBV) as a CT-based indicator of pruning (lower BV5/TBV represents greater pruning). We investigated relationships of CT pruning and histologic remodeling using Pearson correlation, simple linear regression, and multivariable regression with adjustment for age, sex, height, weight, smoking status, and total pack-years. We also tested for effect modification by sex and smoking status. In primary models, more severe CT pruning was associated with greater histologic remodeling. The Pearson correlation coefficient between BV5/TBV and VWA% was -0.41, and in linear regression models, VWA% was 3.13% higher (95% CI: 1.95-4.31%, p < 0.0001) per standard deviation lower BV5/TBV. This association persisted after multivariable adjustment. We found no evidence that these relationships differed by sex or smoking status. Among individuals who underwent resection for lung adenocarcinoma, more severe CT-based vascular pruning was associated with greater histologic arterial remodeling. These findings suggest CT imaging may be a non-invasive indicator of pulmonary vascular pathology.

The impact of pathology grossing protocol measures to improve pathologic nodal staging in lung cancer.

OBJECTIVE: Accurate assessment of lymph node (LN) status is essential for proper staging of resected lung cancer specimens. Here, we assessed pathology-centric interventions to increase the number of peribronchial LNs identified and evaluated in anatomic lung cancer resection specimens as part of a quality improvement initiative. MATERIALS AND METHODS: All non-small cell lung cancer (NSCLC) anatomic resection specimens from 2017 to 2020 were evaluated, comprising two years pre-intervention and one year post-intervention. We instituted 3 measures to increase peribronchial LN yield: 1) educational grossing sessions for pathology assistants and residents, 2) directions to submit additional peribronchial tissue if no LNs were identified grossly, and 3) a hard-stop prior to sign-out by the attending pathologist if no peribronchial LNs were identified. RESULTS: Of the total 227 resection specimens for NSCLC, 107/151 (70.9%) of specimens prior to the intervention had peribronchial LNs identified, whereas after the intervention significantly more (66/76, 86.8%, p < 0.01) specimens had peribronchial LNs identified. In addition, the mean number of peribronchial LNs identified significantly increased from 2.7 ± 3.3 pre-intervention to 4.3 ± 4.0 post-intervention (p < 0.001). Further analysis revealed a strong correlation between peribronchial LN metastases with both overall tumor size and invasive component size (for adenocarcinomas), correlation coefficient 0.974, p < 0.0001. CONCLUSION: Establishing focused grossing measures by pathology led to a significant increase in the number of peribronchial LNs identified and assessed during histopathologic evaluation of anatomic lung cancer resection specimens. Larger tumors are more likely to have occult peribronchial LN metastases, which may warrant more aggressive peribronchial LN assessment for larger tumors.

COVID-19 Vaccination-Related Uptake on FDG PET/CT: An Emerging Dilemma and Suggestions for Management.

As mass COVID-19 vaccination is underway, radiologists are encountering transient FDG uptake in normal or enlarged axillary, supraclavicular, and cervical lymph nodes after ipsilateral deltoid vaccination. This phenomenon may confound interpretation in patients with cancer undergoing FDG PET/CT. In this article, we present our institutional approach for management of COVID-19 vaccine-related lymphadenopathy on FDG PET/CT according to early experience. We suggest performing PET/CT at least 2 weeks after vaccination in patients with a cancer for which interpretation is anticipated to be potentially impacted by the vaccination but optimally 4-6 weeks after vaccination given increased immunogenicity of mRNA vaccines and potentially longer time for resolution than lymphadenopathy after other vaccines. PET/CT should not be delayed when clinically indicated to be performed sooner. Details regarding vaccination should be collected at the time of PET/CT to facilitate interpretation. Follow-up recommendations for postvaccination lymphadenopathy are provided, considering the lymph node's morphology and likely clinical relevance. Consideration should be given to administering the vaccine in the arm contralateral to a unilateral cancer to avoid confounding FDG uptake on the side of cancer. Our preliminary experience and suggested institutional approach should guide radiologists in management of patients with cancer undergoing PET/CT after COVID-19 vaccination.

Chest CT Diagnosis and Clinical Management of Drug-Related Pneumonitis in Patients Receiving Molecular Targeting Agents and Immune Checkpoint Inhibitors: A Position Paper From the Fleischner Society.

Use of molecular targeting agents and immune checkpoint inhibitors (ICIs) has increased the frequency and broadened the spectrum of lung toxicity, particularly in patients with cancer. The diagnosis of drug-related pneumonitis (DRP) is usually achieved by excluding other potential known causes. Awareness of the incidence and risk factors for DRP is becoming increasingly important. The severity of symptoms associated with DRP may range from mild or none to life-threatening with rapid progression to death. Imaging features of DRP should be assessed in consideration of the distribution of lung parenchymal abnormalities (radiologic pattern approach). The CT patterns reflect acute (diffuse alveolar damage) interstitial pneumonia and transient (simple pulmonary eosinophilia) lung abnormality, subacute interstitial disease (organizing pneumonia and hypersensitivity pneumonitis), and chronic interstitial disease (nonspecific interstitial pneumonia). A single drug can be associated with multiple radiologic patterns. Treatment of a patient suspected of having DRP generally consists of drug discontinuation, immunosuppressive therapy, or both, along with supportive measures eventually including supplemental oxygen and intensive care. In this position paper, the authors provide diagnostic criteria and management recommendations for DRP that should be of interest to radiologists, clinicians, clinical trialists, and trial sponsors, among others.

Chest CT Diagnosis and Clinical Management of Drug-related Pneumonitis in Patients Receiving Molecular Targeting Agents and Immune Checkpoint Inhibitors: A Position Paper from the Fleischner Society.

Use of molecular targeting agents and immune checkpoint inhibitors (ICIs) has increased the frequency and broadened the spectrum of lung toxicity, particularly in patients with cancer. The diagnosis of drug-related pneumonitis (DRP) is usually achieved by excluding other potential known causes. Awareness of the incidence and risk factors for DRP is becoming increasingly important. The severity of symptoms associated with DRP may range from mild or none to life-threatening with rapid progression to death. Imaging features of DRP should be assessed in consideration of the distribution of lung parenchymal abnormalities (radiologic pattern approach). The CT patterns reflect acute (diffuse alveolar damage) interstitial pneumonia and transient (simple pulmonary eosinophilia) lung abnormality, subacute interstitial disease (organizing pneumonia and hypersensitivity pneumonitis), and chronic interstitial disease (nonspecific interstitial pneumonia). A single drug can be associated with multiple radiologic patterns. Treatment of a patient suspected of having DRP generally consists of drug discontinuation, immunosuppressive therapy, or both, along with supportive measures eventually including supplemental oxygen and intensive care. In this position paper, the authors provide diagnostic criteria and management recommendations for DRP that should be of interest to radiologists, clinicians, clinical trialists, and trial sponsors, among others. This article is a simultaneous joint publication in Radiology and CHEST. The articles are identical except for stylistic changes in keeping with each journal's style. Either version may be used in citing this article. Published under a CC BY 4.0 license. Online supplemental material is available for this article.

Vascular Pruning on CT and Interstitial Lung Abnormalities in the Framingham Heart Study.

BACKGROUND: Pulmonary vascular disease is associated with poor outcomes in individuals affected by interstitial lung disease. The pulmonary vessels can be quantified with noninvasive imaging, but whether radiographic indicators of vasculopathy are associated with early interstitial changes is not known. RESEARCH QUESTION: Are pulmonary vascular volumes, quantified from CT scans, associated with interstitial lung abnormalities (ILA) in a community-based sample with a low burden of lung disease? STUDY DESIGN AND METHODS: In 2,386 participants of the Framingham Heart Study, we used CT imaging to calculate pulmonary vascular volumes, including the small vessel fraction (a surrogate of vascular pruning). We constructed multivariable logistic regression models to investigate associations of vascular volumes with ILA, progression of ILA, and restrictive pattern on spirometry. In secondary analyses, we additionally adjusted for diffusing capacity and emphysema, and performed a sensitivity analysis restricted to participants with normal FVC and diffusing capacity. RESULTS: In adjusted models, we found that lower pulmonary vascular volumes on CT were associated with greater odds of ILA, antecedent ILA progression, and restrictive pattern on spirometry. For example, each SD lower small vessel fraction was associated with 1.81-fold greater odds of ILA (95% CI, 1.41-2.31; P < .0001), and 1.63-fold greater odds of restriction on spirometry (95% CI, 1.18-2.24; P = .003). Similar patterns were seen after adjustment for diffusing capacity for carbon monoxide, emphysema, and among participants with normal lung function. INTERPRETATION: In this cohort of community-dwelling adults not selected on the basis of lung disease, more severe vascular pruning on CT was associated with greater odds of ILA, ILA progression, and restrictive pattern on spirometry. Pruning on CT may be an indicator of early pulmonary vasculopathy associated with interstitial lung disease.

Assessing invasiveness of subsolid lung adenocarcinomas with combined attenuation and geometric feature models.

The aim of this study was to develop and test multiclass predictive models for assessing the invasiveness of individual lung adenocarcinomas presenting as subsolid nodules on computed tomography (CT). 227 lung adenocarcinomas were included: 31 atypical adenomatous hyperplasia and adenocarcinomas in situ (class H1), 64 minimally invasive adenocarcinomas (class H2) and 132 invasive adenocarcinomas (class H3). Nodules were segmented, and geometric and CT attenuation features including functional principal component analysis features (FPC1 and FPC2) were extracted. After a feature selection step, two predictive models were built with ordinal regression: Model 1 based on volume (log) (logarithm of the nodule volume) and FPC1, and Model 2 based on volume (log) and Q.875 (CT attenuation value at the 87.5% percentile). Using the 200-repeats Monte-Carlo cross-validation method, these models provided a multiclass classification of invasiveness with discriminative power AUCs of 0.83 to 0.87 and predicted the class probabilities with less than a 10% average error. The predictive modelling approach adopted in this paper provides a detailed insight on how the value of the main predictors contribute to the probability of nodule invasiveness and underlines the role of nodule CT attenuation features in the nodule invasiveness classification.

The Growth Rate of Subsolid Lung Adenocarcinoma Nodules at Chest CT.

Background Confirming that subsolid adenocarcinomas show exponential growth is important because it would justify using volume doubling time to assess their growth. Purpose To test whether the growth of lung adenocarcinomas manifesting as subsolid nodules at chest CT is accurately represented by an exponential model. Materials and Methods Patients with lung adenocarcinomas manifesting as subsolid nodules surgically resected between January 2005 and May 2018, with three or more longitudinal CT examinations before resection, were retrospectively included. Overall volume (for all nodules) and solid component volume (for part-solid nodules) were measured over time. A linear mixed-effects model was used to identify the growth pattern (linear, exponential, quadratic, or power law) that best represented growth. The interactions between nodule growth and clinical, CT morphologic, and pathologic parameters were studied. Results Sixty-nine patients (mean age, 70 years ± 9 [standard deviation]; 48 women) with 74 lung adenocarcinomas were evaluated. Overall growth and solid component growth were better represented by an exponential model (adjusted R2 = 0.89 and 0.95, respectively) than by a quadratic model (r2 = 0.88 and 0.93, respectively), a linear model (r2 = 0.87 and 0.92, respectively), or a power law model (r2 = 0.82 and 0.93, respectively). Faster overall volume growth was associated with a history of lung cancer (P < .001), a baseline nodule volume less than 500 mm3 (P = .03), and histologic findings of invasive adenocarcinoma (P < .001). The median volume doubling time of noninvasive adenocarcinoma was significantly longer than that of invasive adenocarcinoma (939 days [interquartile range, 588-1563 days] vs 678 days [interquartile range, 392-916 days], respectively; P = .01). Conclusion The overall volume growth of adenocarcinomas manifesting as subsolid nodules at chest CT was best represented by an exponential model compared with the other tested models. This justifies the use of volume doubling time for the growth assessment of these nodules. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Kuriyama and Yanagawa in this issue.

Preoperative bronchial cytology for the assessment of tumor spread through air spaces in lung adenocarcinoma resection specimens.

BACKGROUND: Tumor spread through air spaces (STAS), a significant prognostic indicator, has been described recently as a pattern of invasion in pulmonary carcinomas. However, questions remain regarding preoperative identification of STAS and whether it represents an in vivo phenomenon versus an ex vivo artifact. METHODS: We retrospectively reviewed 67 paired preoperative bronchoalveolar lavage (BAL) or bronchial washing (BW) cytology specimens with the subsequent lung adenocarcinoma surgical resection specimen to determine whether preoperative cytology could predict STAS. Other clinical, radiologic, and pathologic features of the resected lesions were also correlated with preoperative bronchial cytology results. RESULTS: Positive bronchial cytology was observed in 28 cases (41.8%), 24 of which had STAS (85.7%); however, negative BAL/BW cytology was observed in 39 cases (58.2%), 29 of which had STAS (74.4%) (x2  = 1.27, P = .26, not significant). High-STAS burden was observed in 44 cases (83.0%), 21 (47.7%) with negative BAL/BW and 23 (52.3%) with positive BAL/BW. Low-STAS burden was observed in 9 cases (17.0%), 8 (88.9%) with negative BAL/BW and only 1 (11.1%) with positive BAL/BW (x2  = 5.11, P = .024, significant). For tumors with STAS, a statistically significant difference was identified in the maximal STAS distance from the main tumor edge between BAL/BW-positive and BAL/BW-negative groups (P = .007). Of the remaining clinicopathologic and radiologic features, only visceral pleural invasion was significantly associated with BAL/BW positivity. CONCLUSION: Presurgical bronchial cytology alone cannot adequately predict tumor STAS; however, it may provide useful information regarding the extent and overall burden of STAS on the subsequent resection specimen.

Estimating patient water equivalent diameter from CT localizer images - A longitudinal and multi-institutional study of the stability of calibration parameters.

PURPOSE: Water equivalent diameter (WED) is a robust patient-size descriptor. Localizer-based WED estimation is less sensitive to truncation errors resulting from limited field of view, and produces WED estimates at different locations within one localizer radiograph, prior to the initiation of axial scans. This method is considered difficult to implement by the clinical community due to the necessary calibration between localizer pixel values (LPV) and attenuation, and the unknown stability of calibration results across scanners and over time. We investigated the stability of calibration results across 25 computed tomography (CT) scanners from three medical centers, and their stability over 3 âˆ¼ 29 months for 14 of those scanners. METHODS: Localizer and axial images of ACR and body computed tomography dose index phantoms were acquired, using routine clinical techniques (120 kV and lateral localizers) on each of the 25 CT scanners: 8 GE scanners (CT750HD, VCT, and Revolution), 8 Siemens scanners (Definition AS, Force, Flash, and Edge), 5 Canon scanners (Aquilion-One, Aquilion-Prime80, and Aquilion-64), and 4 Philips scanners (iCT 256, iQon, and Ingenuity). By associating axial images with the corresponding localizer lines, the relationship between the scaled water equivalent area (WEA) and averaged LPV were established through regression analysis. RESULTS: Linear relationships between the scaled WEA and the averaged LPV were observed in all 25 CT scanners ( R 2 > 0.999 ). Calibration parameters were similar for CT scanners from the same vendor: the coefficients of variation (COV) were ≤ 1% in all four vendor groups for the calibration slope, and < 7% for the intercept. By analyzing the deviation of WED resulted from errors in the calibration slope or intercept alone, we derived the tolerance ranges for the slope or intercept for a given WED error level. The variation of slope and intercept from different CT scanners of the same vendor introduced <±2.5% error in the estimated WED for subjects of 20 and 30-cm WED. The calibration parameters remained stable over time, with the maximum deviations all within the boundary values that introduce ±2.5% error in the estimated WED for subjects of 20 and 30-cm WED. CONCLUSIONS: The stability in calibration results among CT scanners of the same vendor and over time demonstrated the feasibility of implementing WED estimation for routine clinical use.

Growth Assessment of Pulmonary Adenocarcinomas Manifesting as Subsolid Nodules on CT: Comparison of Diameter-Based and Volume Measurements.

RATIONALE AND OBJECTIVES: To analyze the performances of diameter-based measurements, either using diameters, or by calculating diameter-based volumes, as compared to volume measurements in assessing growth of pulmonary adenocarcinomas manifesting as subsolid nodules on CT. MATERIALS AND METHODS: In this IRB-approved, retrospective study, 74 pulmonary adenocarcinomas presenting as subsolid nodules and resected in 69 patients (21 men, 48 women, mean age 70 ± 9 years) were included. Three CTs were available for each patient. Nodule size on each CT was assessed with diameter measurements, calculated volume based on diameter measurements, and measured volume. Nodule growth was defined as an increase of measured volume ≥25% between two sequential CTs. Sensitivity, specificity, accuracy, positive and negative predictive values of diameter-based measurements for growth assessment were calculated. Nodule characteristics were compared with nonparametric tests and analysis of variance. RESULTS: There were fewer growing nodules during CT1-CT2 interval (n = 22, 30%) than during CT2-CT3 interval (n = 33, 45%, p =.060). Specificity and negative predictive value of diameter-based measurements for growth assessment ranged respectively from 52 to 77% and 81 to 83% between CT1 and CT2, and from 66 to 76% and 79 to 90% between CT2 and CT3. Nongrowing nodules tended to be larger, regardless how size was measured, and some of these differences in size were statistically significant (p =.002 to .046). CONCLUSION: For pulmonary adenocarcinomas presenting as subsolid nodules on CT, diameter-based assessment of nodule volume is reasonably accurate at confirming a lack of nodule growth but may overestimate actual growth, as compared to growth assessment based on measured volume.

Inter-observer agreement in identifying traction bronchiectasis on computed tomography: its improvement with the use of the additional criteria for chronic fibrosing interstitial pneumonia.

PURPOSE: To assess inter-observer variability in identifying traction bronchiectasis on computed tomography (CT) using additional criteria for chronic fibrosing interstitial pneumonia. METHODS: Seven experts categorized CT image set representing 39 patients into three groups on the basis of the presence of traction bronchiectasis, using a three-point scale: 3-definitely/probably yes; 2-possibly yes; and 1-definitely/probably no. This scale served as a reference standard. The image set included cases of chronic fibrosing interstitial pneumonia, non-interstitial lung disease, and difficult-to-determine cases. Forty-eight observers similarly assessed the same image set, first according to the Fleischner Society definition, and second with additional criteria, in which traction bronchiectasis was observed exclusively in chronic fibrosing interstitial pneumonia. The agreement level between the reference standard and each observer's evaluation in each session was calculated using weighted kappa values which were compared between the two sessions using a paired t test. RESULTS: The mean weighted kappa value for all observers was significantly higher in the second reading session (mean 0.75) than in the first reading session (mean 0.62) (p < 0.001). CONCLUSION: Inter-observer agreement in identifying traction bronchiectasis improves when using the additional criteria which specify chronic fibrosing interstitial pneumonia as the underlying disease.

Radiographic pulmonary vessel volume, lung function and airways disease in the Framingham Heart Study.

Radiographic abnormalities of the pulmonary vessels, such as vascular pruning, are common in advanced airways disease, but it is unknown if pulmonary vascular volumes are related to measures of lung health and airways disease in healthier populations.In 2388 participants of the Framingham Heart Study computed tomography (CT) sub-study, we calculated total vessel volumes and the small vessel fraction using automated CT image analysis. We evaluated associations with measures of lung function, airflow obstruction on spirometry and emphysema on CT. We further tested if associations of vascular volumes with lung function were present among those with normal forced expiratory volume in 1 s and forced vital capacity.In fully adjusted linear and logistic models, we found that lower total and small vessel volumes were consistently associated with worse measures of lung health, including lower spirometric volumes, lower diffusing capacity and/or higher odds of airflow obstruction. For example, each standard deviation lower small vessel fraction (indicating more severe pruning) was associated with a 37% greater odds of obstruction (OR 1.37, 95% CI 1.11-1.71, p=0.004). A similar pattern was observed in the subset of participants with normal spirometry.Lower total and small vessel pulmonary vascular volumes were associated with poorer measures of lung health and/or greater odds of airflow obstruction in this cohort of generally healthy adults without high burdens of smoking or airways disease. Our findings suggest that quantitative CT assessment may detect subtle pulmonary vasculopathy that occurs in the setting of subclinical and early pulmonary and airways pathology.