Incidence of Interstitial Lung Abnormalities: The MESA Lung Study.

The incidence of newly developed interstitial lung abnormalities (ILA) and fibrotic ILA have not been previously reported.Trained thoracic radiologists evaluated 13 944 cardiac CT scans for the presence of ILA in 6197 Multi-Ethnic Study of Atherosclerosis longitudinal cohort study participants >45 years of age from 2000 to 2012. 5% of the scans were re-read by the same or a different observer in a blinded fashion. After exclusion of participants with ILA at baseline, incidence rates and incidence rate ratios for ILA and fibrotic ILA were calculated.The intra-reader agreement of ILA was 92.0% (Gwet AC1=0.912, ICC=0.982) and the inter-reader agreement of ILA was 83.5% (Gwet AC1=0.814; ICC=0.969). Incidence of ILA and fibrotic ILA was estimated to be 13.1 cases/1000 person-years and 3.5/1000 person-years, respectively. In multivariable analyses, age (HR 1.06 (1.05, 1.08), p <0.001; HR 1.08 (1.06, 1.11), p <0.001), high attenuation area (HAA) at baseline (HR 1.05 (1.03, 1.07), p <0.001; HR 1.06 (1.02, 1.10), p=0.002), and the MUC5B promoter SNP (HR 1.73 (1.17, 2.56) p=0.01; HR 4.96 (2.68, 9.15), p <0.001) were associated with incident ILA and fibrotic ILA, respectively. Ever smoking (HR 2.31 (1.34, 3.96), p= 0.002) and an IPF polygenic risk score (HR 2.09 (1.61-2.71), p<0.001) were associated only with incident fibrotic ILA.Incident ILA and fibrotic ILA were estimated by review of cardiac imaging studies. These findings may lead to wider application of a screening tool for atherosclerosis to identify preclinical lung disease.

Lung Cancer Risk Associated With New Solid Nodules in the National Lung Screening Trial.

OBJECTIVE: As low-dose CT (LDCT) lung cancer screening moves into routine clinical practice, evaluation of nodules identified as new becomes critical. We examine the frequency and clinical outcomes of new lung nodules reported at the two postbaseline annual screening examinations (hereafter referred to as postbaseline time 1 [T1] and time 2 [T2]), compared with those detected at baseline in the National Lung Screening Trial. MATERIALS AND METHODS: Radiologists classified nodules detected at T1 and T2 as new or preexisting on the basis of comparison with findings from prior LDCT screening examinations. Subjects were tracked for lung cancer incidence and mortality. We examined the incidence of new nodules and their associated lung cancer risk by nodule size (i.e., mean diameter). RESULTS: A total of 25,002 subjects underwent the baseline LDCT screening examination and either a T1 or T2 LDCT screen. At both T1 and T2, 2.6% of subjects had new solid nodules. Of the new solid nodules, 53.0% were < 6 mm, 29.5% were 6 to < 10 mm, and 17.1% were ≥ 10 mm. Lung cancer risk (defined as diagnosis within 2 years of baseline) increased from 1.1% for nodules < 4 mm to 24.0% for those ≥ 20 mm. Compared with solid nodules detected at baseline, the cancer risk was higher for new solid nodules that were 4 to < 6 mm (p < 0.001) and 6 to < 8 mm (p < 0.001) but lower for new nodules ≥ 20 mm (p = 0.03). Cancers associated with new nodules had significantly poorer survival than did those associated with baseline nodules and were significantly less likely to be adenocarcinoma. CONCLUSION: The incidence of new nodules was 2-3% annually, with the cancer risk increasing by nodule size. New nodules may convey differential lung cancer risks by size, compared with baseline nodules.

Rheumatoid arthritis-associated autoantibodies and subclinical interstitial lung disease: the Multi-Ethnic Study of Atherosclerosis.

BACKGROUND: Adults with interstitial lung disease (ILD) often have serologic evidence of autoimmunity of uncertain significance without overt autoimmune disease. We examined associations of rheumatoid arthritis (RA)-associated antibodies with subclinical ILD in community-dwelling adults. METHODS: We measured serum rheumatoid factor (RF) and anticyclic citrullinated peptide antibody (anti-CCP) and high attenuation areas (HAAs; CT attenuation values between -600 and -250 Hounsfield units) on cardiac CT in 6736 community-dwelling US adults enrolled in the Multi-Ethnic Study of Atherosclerosis. We measured interstitial lung abnormalities (ILAs) in 2907 full-lung CTs at 9.5-year median follow-up. We used generalised linear and additive models to examine associations between autoantibodies and both HAA and ILA, and tested for effect modification by smoking. RESULTS: In adjusted models, HAA increased by 0.49% (95% CI 0.11% to 0.86%) per doubling of RF IgM and by 0.95% (95% CI 0.50% to 1.40%) per RF IgA doubling. ILA prevalence increased by 11% (95% CI 3% to 20%) per RF IgA doubling. Smoking modified the associations of both RF IgM and anti-CCP with both HAA and ILA (interaction p values varied from 0.01 to 0.09). Among ever smokers, HAA increased by 0.81% (95% CI 0.33% to 1.30%) and ILA prevalence increased by 14% (95% CI 5% to 24%,) per RF IgM doubling; and HAA increased by 1.31% (95% CI 0.45% to 2.18%) and ILA prevalence increased by 13% (95% CI 2% to 24%) per anti-CCP doubling. Among never smokers, no meaningful associations were detected. CONCLUSIONS: RA-related autoimmunity is associated with both quantitative and qualitative subclinical ILD phenotypes on CT, particularly among ever smokers.

National lung screening trial: variability in nodule detection rates in chest CT studies.

PURPOSE: To characterize the variability in radiologists' interpretations of computed tomography (CT) studies in the National Lung Screening Trial (NLST) (including assessment of false-positive rates [FPRs] and sensitivity), to examine factors that contribute to variability, and to evaluate trade-offs between FPRs and sensitivity among different groups of radiologists. MATERIALS AND METHODS: The HIPAA-compliant NLST was approved by the institutional review board at each screening center; all participants provided informed consent. NLST radiologists reported overall screening results, nodule-specific findings, and recommendations for diagnostic follow-up. A noncalcified nodule of 4 mm or larger constituted a positive screening result. The FPR was defined as the rate of positive screening examinations in participants without a cancer diagnosis within 1 year. Descriptive analyses and mixed-effects models were utilized. The average odds ratio (OR) for a false-positive result across all pairs of radiologists was used as a measure of variability. RESULTS: One hundred twelve radiologists at 32 screening centers each interpreted 100 or more NLST CT studies, interpreting 72 160 of 75 126 total NLST CT studies in aggregate. The mean FPR for radiologists was 28.7% ± 13.7 (standard deviation), with a range of 3.8%-69.0%. The model yielded an average OR of 2.49 across all pairs of radiologists and an OR of 1.83 for pairs within the same screening center. Mean FPRs were similar for academic versus nonacademic centers (27.9% and 26.7%, respectively) and for centers inside (25.0%) versus outside (28.7%) the U.S. "histoplasmosis belt." Aggregate sensitivity was 96.5% for radiologists with FPRs higher than the median (27.1%), compared with 91.9% for those with FPRs lower than the median (P = .02). CONCLUSION: There was substantial variability in radiologists' FPRs. Higher FPRs were associated with modestly higher sensitivity.

Evaluation of reader variability in the interpretation of follow-up CT scans at lung cancer screening.

PURPOSE: To measure reader agreement in determining whether lung nodules detected at baseline screening computed tomography (CT) had changed at subsequent screening examinations and to evaluate the variability in recommendations for further follow-up. MATERIALS AND METHODS: All subjects were enrolled in the National Lung Screening Trial (NLST), and each participant consented to the use of their de-identified images for research purposes. The authors randomly selected 100 cases of nodules measuring at least 4.0 mm at 1-year screening CT that were considered by the original screening CT reader to be present on baseline CT scans; nodules considered by the original reader to have changed were oversampled. Selected images from each case showing the entire nodule at both examinations were preloaded on a picture archiving and communication system workstation. Nine radiologists served as readers, and they evaluated whether the nodule was present at baseline and recorded the bidimensional measurements and nodule characteristics at each examination, presence or absence of change, results of screening CT, and follow-up recommendations (high-level follow-up, low-level follow-up, no follow-up). RESULTS: On the basis of reviews during case selection, five nodules seen at follow-up were judged not to have been present at baseline; for 19 of the remaining 95 cases, at least one reader judged the nodule not to have been present at baseline. For the 76 nodules that were unanimously considered to have been present at baseline, 21%-47% (mean ± standard deviation, 30% ± 9) were judged to have grown. The κ values were similar for growth (κ = 0.55) and a positive screening result (κ = 0.51) and were lower for a change in margins and attenuation (κ = 0.27-0.31). The κ value in the recommendation of high- versus low-level follow-up was high (κ = 0.66). CONCLUSION: Reader agreement on nodule growth and screening result was moderate to substantial. Agreement on follow-up recommendations was lower.

Incidental renal tumours on low-dose CT lung cancer screening exams.

Introduction Renal cancer incidence has increased markedly in the United States in recent decades, largely due to incidentally detected tumours from computed tomography imaging. Here, we analyze the potential for low-dose computed tomography lung cancer screening to detect renal cancer. Methods The National Lung Screening Trial randomized subjects to three annual screens with either low-dose computed tomography or chest X-ray. Eligibility criteria included 30 + pack-years, current smoking or quit within 15 years, and age 55-74. Subjects were followed for seven years. Low-dose computed tomography screening forms collected information on lung cancer and non-lung cancer abnormalities, including abnormalities below the diaphragm. A reader study was performed on a sample of National Lung Screening Trial low-dose computed tomography images assessing presence of abnormalities below the diaphragms and abnormalities suspicious for renal cancer. Results There were 26,722 and 26,732 subjects enrolled in the low-dose computed tomography and chest X-ray arms, respectively, and there were 104 and 85 renal cancer cases diagnosed, respectively (relative risk = 1.22, 95% CI: 0.9-1.5). From 75,126 low-dose computed tomography screens, there were 46 renal cancer diagnoses within one year. Abnormalities below the diaphragm rates were 39.1% in screens with renal cancer versus 4.1% in screens without (P < 0.001). Cases with abnormalities below the diaphragms had shorter median time to diagnosis than those without (71 vs. 160 days, P = 0.004). In the reader study, 64% of renal cancer cases versus 13% of non-cases had abnormalities below the diaphragms; 55% of cases and 0.8% of non-cases had a finding suspicious for renal cancer (P < 0.001). Conclusion Low-dose computed tomography screens can potentially detect renal cancers. The benefits to harms tradeoff of incidental detection of renal tumours on low-dose computed tomography is unknown.

Improved identification of sternal injuries with multidetector computed tomography (MDCT): sagittal reconstructions.

Chest computed tomography is acquired in the axial plane, but sternal injuries may be missed on axial images. This study hypothesized that sagittal sternal reconstruction images improve detection of sternal injury and radiologist's confidence in diagnosis compared to axial images. Five radiologists independently reviewed first axial images and on a different day sagittal images of a retrospective set of trauma cases recording presence/absence of a sternal injury and/or adjacent hematoma. The reviewer's confidence in the presence/absence of a sternal injury was assessed on a 5-point scale. Sagittal reconstructions generally yielded higher interreader agreement and confidence indices on statistical analysis.

Pictorial review of the role of multidetector computed tomography imaging in the postoperative evaluation of congenital heart disease.

Echocardiography and cardiac magnetic resonance imaging are the methods of choice for preoperative and postoperative assessments of most congenital heart diseases. However, multidetector computed tomographic angiography of the chest is a complementary imaging technique especially in postoperative evaluations. To accurately interpret those computed tomography examinations, an appropriate study protocol, knowledge of the details of surgical procedures, and their complications are essential. In this pictorial review, we discuss our computed tomography technique with a number of illustrative cases with varied postoperative appearances and complications after some of the commonly performed surgical procedures.

Short- and long-term lung cancer risk associated with noncalcified nodules observed on low-dose CT.

Chemoprevention is an important potential tool in reducing lung cancer incidence. Noncalcified nodules (NCN) observed on low-dose computed tomography (LDCT) have been proposed as intermediate endpoints in chemoprevention trials, but whether NCNs represent cancer precursors is unclear. We analyzed data from subjects in the LDCT arm of the National Lung Screening Trial (NLST) to examine short- and long-term lung cancer risks associated with NCNs and to elucidate whether some NCNs may be cancer precursors. NLST subjects received a baseline and two additional LDCT screens and were followed for a median of 6.5 years. We examined lung cancer incidence over three distinct periods from baseline-0-23 months (short-term), 24-59 months (medium-term), and 60-84 months (long-term)-in relation to baseline NCN characteristics. Spatially, lung cancer incidence was analyzed at the person, lung, and lobe levels relative to NCN location. A total of 26,272 subjects received the baseline LDCT screen, with 468, 413, and 190 lung cancers observed in the three periods. The presence of an NCN gave significantly elevated long-term lung cancer risk ratios (RR) of 1.8, 2.4, and 3.5 at the person, lung, and lobe levels; corresponding short-term RRs were 10.3, 16.8, and 38.0. Ground-glass attenuation was positively associated with long-term lung cancer risk but inversely associated with short-term risk; NCN size was positively associated with short-term risk but not significantly associated with long-term risk. That NCNs convey significantly elevated excess long-term of lung cancer lends evidence to the hypothesis that some NCNs may be cancer precursors.

Pictorial review of multidetector CT imaging of the preoperative evaluation of congenital heart disease.

Sequential segmental approach is an efficient method for complete evaluation of complex congenital heart diseases (CHD). Although echocardiography is the imaging technique of choice, recent advances in computed tomography and cardiac magnetic resonance have given a new dimension to the traditional diagnostic assessment of CHD. CT has advantages of fast speed, higher spatial resolution, and simultaneous lung and airway visualization. The purpose of this pictorial review is to discuss the role of CT and emphasize its protocol and the segmental approach for comprehensive assessment of CHD.