Segmentation of Juxtapleural Pulmonary Nodules Using a Robust Surface Estimate

An algorithm was developed to segment solid pulmonary nodules attached to the chest wall in computed tomography scans. The pleural surface was estimated and used to segment the nodule from the chest wall. To estimate the surface, a robust approach was used to identify points that lie on the pleural surface but not on the nodule. A 3D surface was estimated from the identified surface points. The segmentation performance of the algorithm was evaluated on a database of 150 solid juxtapleural pulmonary nodules. Segmented images were rated on a scale of 1 to 4 based on visual inspection, with 3 and 4 considered acceptable. This algorithm offers a large improvement in the success rate of juxtapleural nodule segmentation, successfully segmenting 98.0% of nodules compared to 81.3% for a previously published plane-fitting algorithm, which will provide for the development of more robust automated nodule measurement methods

Second-Hand Tobacco Smoke in Never Smokers Is a Significant Risk Factor for Coronary Artery Calcification

ObjectivesThe aim of this study was to assess the relationship of the extent of subclinical atherosclerosis measured by coronary artery calcification (CAC) to the extent of second-hand tobacco smoke (SHTS) exposure in asymptomatic people who never smoked.BackgroundAn association between SHTS and CAC was recently reported in a single study, but the quantitative aspects of the relationship are not known.MethodsA cohort of 3,098 never smokers 40 to 80 years of age, enrolled in the FAMRI-IELCAP (Flight Attendant Medical Research Institute International Early Lung Cancer Action Program) screening program, completed a SHTS questionnaire, and had a low-dose nongated computed tomography scan. The questionnaire provided a quantitative score for total SHTS exposure, as well as separately as a child and as an adult at home and at work; 4 categories of exposure to SHTS were identified (minimal, low, moderate, and high exposure). CAC was graded using a previously validated ordinal scale score that ranged from 0 to 12. Logistic regression analysis of the prevalence and ordered logistic regression analysis of the extent of CAC were performed to assess the independent contribution of SHTS adjusted for age, sex, diabetes, hypercholesterolemia, hypertension, and renal disease. Linear and quadratic regression analyses of CAC and SHTS were performed.ResultsThe prevalence of CAC was 24.3% (n = 754) and was significantly higher in those with more than minimal SHTS exposure compared with those with minimal SHTS exposure (26.4% vs. 18.5%, p < 0.0001). The adjusted odds ratios for CAC prevalence were 1.54 (95% confidence interval: 1.17 to 2.20) for low SHTS exposure, 1.60 (95% confidence interval: 1.21 to 2.10) for moderate exposure, and 1.93 (95% confidence interval: 1.49 to 2.51) for high exposure. The association of the extent of SHTS with the extent of CAC was confirmed by the adjusted odds ratio (p < 0.0001).ConclusionsThe presence and extent of CAC were associated with extent of SHTS exposure even when adjusted for other risk factors for CAC, suggesting that SHTS exposure causes CAC

Change in quality of life of stage IA lung cancer patients after sublobar resection and lobectomy

© Journal of Thoracic Disease. All rights reserved. Background: Few studies have examined the differential impact of sublobar resection (SL) and lobectomy (L) on quality of life (QoL) during the first postoperative year. Methods: We used a prospective cohort of Stage IA lung cancer patients undergoing video-assisted thoracoscopic surgery (VATS) from the Initiative for Early Lung Cancer Research on Treatment. QoL was measured before surgery, and within 4, 6, and 12 months post-surgery using three validated instruments: SF-12 [physical (PCS) and mental health (MCS)], FACT-LCS (lung-cancer-symptoms), and the PHQ-4 (anxiety and depression subscales). Locally weighted smoothing curve (LOWESS) was fitted to identify the best interval knot for the change in the QoL trend post-surgery. After adjusting for demographic and clinical variables, an adjusted piecewise linear mixed effects model was developed to estimate differences in baseline and 12-month scores, and rates of change for each QoL measure. Results: SL resection was performed in 127 (63.2%) and L in 74 (36.8%) patients. LOWESS plots suggested that the shift of QoL (interval knot) was at 2 months post-surgery. Decreases in PCS scores were less severe for SL than L patients 2 months post-surgery (−0.18 vs. −2.30, P=0.02); while subsequent improvements were observed for both groups (SL: +0.29 vs. L: +0.74, P=0.06). SL patients reported significantly better scores a year post-surgery compared to baseline (P=0.003), while L patients did not. Anxiety decreased at similar rates for both SL and L patients within 2 months post-surgery (P=0.18), then stabilized for the remaining months. MCS and depression scores remained stable in both groups throughout. QoL scores were lower for women than for men, but only significantly worse for the lung-cancer-symptoms (P=0.003) and anxiety (P=0.04). Conclusions: SL patients fared better in physical health and lung cancer symptoms than L patients. The first two postoperative months showed the most significant change which suggests targeting postoperative intervention during that time

MR imaging of therapy-induced changes of bone marrow

MR imaging of bone marrow infiltration by hematologic malignancies provides non-invasive assays of bone marrow cellularity and vascularity to supplement the information provided by bone marrow biopsies. This article will review the MR imaging findings of bone marrow infiltration by hematologic malignancies with special focus on treatment effects. MR imaging findings of the bone marrow after radiation therapy and chemotherapy will be described. In addition, changes in bone marrow microcirculation and metabolism after anti-angiogenesis treatment will be reviewed. Finally, new specific imaging techniques for the depiction of regulatory events that control blood vessel growth and cell proliferation will be discussed. Future developments are directed to yield comprehensive information about bone marrow structure, function and microenvironment

Evaluation of lung MDCT nodule annotation across radiologists and methods

RATIONALE AND OBJECTIVES: Integral to the mission of the National Institutes of Health–sponsored Lung Imaging Database Consortium is the accurate definition of the spatial location of pulmonary nodules. Because the majority of small lung nodules are not resected, a reference standard from histopathology is generally unavailable. Thus assessing the source of variability in defining the spatial location of lung nodules by expert radiologists using different software tools as an alternative form of truth is necessary. MATERIALS AND METHODS: The relative differences in performance of six radiologists each applying three annotation methods to the task of defining the spatial extent of 23 different lung nodules were evaluated. The variability of radiologists’ spatial definitions for a nodule was measured using both volumes and probability maps (p-map). Results were analyzed using a linear mixed-effects model that included nested random effects. RESULTS: Across the combination of all nodules, volume and p-map model parameters were found to be significant at P < .05 for all methods, all radiologists, and all second-order interactions except one. The radiologist and methods variables accounted for 15% and 3.5% of the total p-map variance, respectively, and 40.4% and 31.1% of the total volume variance, respectively. CONCLUSION: Radiologists represent the major source of variance as compared with drawing tools independent of drawing metric used. Although the random noise component is larger for the p-map analysis than for volume estimation, the p-map analysis appears to have more power to detect differences in radiologist-method combinations. The standard deviation of the volume measurement task appears to be proportional to nodule volume

Emphysema Predicts Hospitalisation and Incident Airflow Obstruction among Older Smokers: A Prospective Cohort Study

Emphysema on CT is common in older smokers. We hypothesised that emphysema on CT predicts acute episodes of care for chronic lower respiratory disease among older smokers.Participants in a lung cancer screening study age ≥ 60 years were recruited into a prospective cohort study in 2001-02. Two radiologists independently visually assessed the severity of emphysema as absent, mild, moderate or severe. Percent emphysema was defined as the proportion of voxels ≤ -910 Hounsfield Units. Participants completed a median of 5 visits over a median of 6 years of follow-up. The primary outcome was hospitalization, emergency room or urgent office visit for chronic lower respiratory disease. Spirometry was performed following ATS/ERS guidelines. Airflow obstruction was defined as FEV1/FVC ratio <0.70 and FEV1<80% predicted.Of 521 participants, 4% had moderate or severe emphysema, which was associated with acute episodes of care (rate ratio 1.89; 95% CI: 1.01-3.52) adjusting for age, sex and race/ethnicity, as was percent emphysema, with similar associations for hospitalisation. Emphysema on visual assessment also predicted incident airflow obstruction (HR 5.14; 95% CI 2.19-21.1).Visually assessed emphysema and percent emphysema on CT predicted acute episodes of care for chronic lower respiratory disease, with the former predicting incident airflow obstruction among older smokers