Inter-observer and inter-examination variability of manual vertebral bone attenuation measurements on computed tomography.

OBJECTIVE: To determine inter-observer and inter-examination variability of manual attenuation measurements of the vertebrae in low-dose unenhanced chest computed tomography (CT). METHODS: Three hundred and sixty-seven lung cancer screening trial participants who underwent baseline and repeat unenhanced low-dose CT after 3 months because of an indeterminate lung nodule were included. The CT attenuation value of the first lumbar vertebrae (L1) was measured in all CTs by one observer to obtain inter-examination reliability. Six observers performed measurements in 100 randomly selected CTs to determine agreement with limits of agreement and Bland-Altman plots and reliability with intraclass correlation coefficients (ICCs). Reclassification analyses were performed using a threshold of 110 HU to define osteoporosis. RESULTS: Inter-examination reliability was excellent with an ICC of 0.92 (p < 0.001). Inter-examination limits of agreement ranged from -26 to 28 HU with a mean difference of 1 ± 14 HU. Inter-observer reliability ICCs ranged from 0.70 to 0.91. Inter-examination variability led to 11.2 % reclassification of participants and inter-observer variability led to 22.1 % reclassification. CONCLUSIONS: Vertebral attenuation values can be manually quantified with good to excellent inter-examination and inter-observer reliability on unenhanced low-dose chest CT. This information is valuable for early detection of osteoporosis on low-dose chest CT. KEY POINTS: • Vertebral attenuation values can be manually quantified on low-dose unenhanced CT reliably. • Vertebral attenuation measurements may be helpful in detecting subclinical low bone density. • This could become of importance in the detection of osteoporosis.

Smokers with emphysema and small airway disease on computed tomography have lower bone density.

Osteoporosis is more common in patients with COPD and in smokers. The aim of this study was to assess whether measures of emphysema and airway disease on computed tomography (CT) were associated with lower bone density or vertebral fractures in smokers with and without COPD. For this purpose, we included participants from the NELSON lung cancer screening trial. Bone density was measured as Hounsfield Units in the first lumbar vertebra, and vertebral fractures were assessed semiquantitatively. The 15th percentile method (Perc15) was used to assess emphysema, and the airway lumen perimeter (Pi10) was used for airway wall thickness. Expiratory/inspiratory-ratiomean lung density (E/I-ratioMLD) was used as a measure for air trapping and tracheal index to assess tracheal deformity. Linear regression models and logistic regression models were used to assess associations between CT biomarkers, bone density, and presence of fractures. Exactly 1,093 male participants were eligible for analysis. Lower Perc15 and higher E/I-ratioMLD were significantly associated with lower bone density (b=-1.27, P=0.02 and b=-0.37, P=0.02, respectively). Pi10 and tracheal index were not associated with bone density changes. CT-derived biomarkers were not associated with fracture prevalence. Bone density is lower with increasing extent of emphysema and small airway disease but is not associated with large airway disease and tracheal deformity. This may indicate the necessity to measure bone density early in smokers with emphysema and air trapping to prevent vertebral fractures.

Association of chronic obstructive pulmonary disease and smoking status with bone density and vertebral fractures in male lung cancer screening participants.

We studied the vertebral fracture prevalence on low-dose chest computed tomography (CT) in male lung cancer screening participants and the association of fractures and bone density with chronic obstructive pulmonary disease (COPD) and smoking. 1140 male current and former smokers with ≥ 16.5 packyears from the NELSON lung cancer screening trial were included. Age, body mass index, and smoking status were registered. CT scans and pulmonary function tests were obtained on the same day. On CT, vertebral fractures and bone density were measured. The cohort had a mean age of 62.5 years (standard deviation 5.2) old; 531 (46.6%) had quit smoking; and 437 (38.3%) had COPD. Of the group, 100 (8.8%) participants had a vertebral fracture. Fracture prevalence was higher in current compared to former smokers (11.3% versus 5.8%, p = 0.001), but similar in participants with COPD compared to those without (9.6% versus 8.3%, p = 0.430). The multivariable adjusted odds ratio for fracture presence was 1.79 (95% CI: 1.13-2.84) in current smokers and 1.08 (95% CI: 0.69-1.67) in COPD participants. Bone density was lower in current compared to former smokers (103.2 HU versus 108.7 HU, p = 0.006) and in participants with COPD compared to those without [100.7 Hounsfield Units (HU) versus 108.9 HU, p < 0.001]. In multivariate analysis, smoking status and COPD status were independently associated with bone density, corrected for age and body mass index. In conclusion, our study shows that lung cancer screening participants have a substantial vertebral fracture burden. Fractures are more common in current smokers, who also have lower bone density. We could not confirm that COPD is independently associated with vertebral fractures.

Nasal endoscopy is recommended for diagnosing adults with chronic rhinosinusitis.

OBJECTIVE: To assess the diagnostic value of nasal endoscopic findings in adults suspected of chronic rhinosinusitis. DATA SOURCES: PubMed, EMBASE, and the Cochrane Library. REVIEW METHODS: A comprehensive search was performed up to March 5, 2013. Articles that assessed the diagnostic value of nasal endoscopy in adults suspected of chronic rhinosinusitis were included. For selected articles, the study design was assessed for directness of evidence and risk of bias. Prevalence, positive, and negative predictive values were extracted from reported data. RESULTS: Out of 3899 unique publications, we included 3 diagnostic studies with a high directness of evidence and a low or moderate risk of bias for data extraction. They showed a prevalence of chronic rhinosinusitis (diagnosed with computed tomography) of .40 to .56. Compared with posterior probabilities we found an added value for ruling in chronic rhinosinusitis by a positive nasal endoscopy of 25% to 28% and an added value for ruling out chronic rhinosinusitis by a negative nasal endoscopy of 5% to 30%. CONCLUSION AND RECOMMENDATION: Computed tomography is not considered necessary in case of a positive nasal endoscopy. While nasal endoscopy cannot rule out chronic rhinosinusitis, we advise computed tomography only for patients with a prolonged or complicated course of rhinosinusitis.