Comparison of CT Lung Density Measurements between Standard Full-Dose and Reduced-Dose Protocols

Hatt, Charles R.; Oh, Andrea; Obuchowski, Nancy A.; Charbonnier, Jean-Paul; Lynch, David A.; Humphries, Stephen

doi:10.1148/ryct.2021200503

Cited by 15 publications

(8 citation statements)

References 29 publications

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“…Deployer chest HRCT scans were acquired on either a Siemens Sensation 64 or Siemens AS 128 scanner using a standardized protocol, as used in Phase 3 of the COPDGene Study 22 . Thin sections (0.5 to 0.75 mm slice thickness) with a moderately high spatial frequency reconstruction algorithm were used to enhance parenchymal and small airways findings.…”

Section: Methodsmentioning

confidence: 99%

Findings on High Resolution Computed Tomography in Symptomatic Veterans with Deployment-Related Lung Disease

Rose,

Zell-Baran,

Cool

et al. 2023

Journal of Thoracic Imaging

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Purpose: Military deployment to dusty, austere environments in Southwest Asia and Afghanistan is associated with symptomatic airways diseases including asthma and bronchiolitis. The utility of chest high-resolution computed tomographic (HRCT) imaging in lung disease diagnosis in this population is poorly understood. We investigated visual assessment of HRCT for identifying deployment-related lung disease compared with healthy controls. Materials and Methods: Chest HRCT images from 46 healthy controls and 45 symptomatic deployed military personnel with clinically confirmed asthma and/or biopsy-confirmed distal lung disease were scored by 3 independent thoracic radiologists. We compared demographic and clinical characteristics and frequency of imaging findings between deployers and controls, and between deployers with asthma and those with biopsy-confirmed distal lung disease, using χ2, Fisher exact or t tests, and logistic regression where appropriate. We also analyzed inter-rater agreement for imaging findings. Results: Expiratory air trapping was the only chest CT imaging finding that was significantly more frequent in deployers compared with controls. None of the 24 deployers with biopsy-confirmed bronchiolitis and/or granulomatous pneumonitis had HRCT findings of inspiratory mosaic attenuation or centrilobular nodularity. Only 2 of 21 with biopsy-proven emphysema had emphysema on HRCT. Conclusions: Compared with surgical lung biopsy, visual assessment of HRCT showed few abnormalities in this small cohort of previously deployed symptomatic veterans with normal or near-normal spirometry.

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Section: Methodsmentioning

confidence: 99%

Findings on High Resolution Computed Tomography in Symptomatic Veterans with Deployment-Related Lung Disease

Rose,

Zell-Baran,

Cool

et al. 2023

Journal of Thoracic Imaging

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“…All HRCT scans were acquired using the same reduced-dose protocol as that used in Phase 3 of the COPDGene © study [ 39 ]. Thin sections (0.5–0.75 mm slice thickness) with a high spatial frequency reconstruction algorithm were used to enhance parenchymal and small airways findings.…”

Section: Methodsmentioning

confidence: 99%

“…Emphysema predominant phenotype was defined as ≥ 10% low attenuation areas based on LAA%-950. A cut point of 5% has been suggested for higher dose CT imaging that was typical with earlier generations of equipment, but recent work suggests that a greater cut point is more appropriate for reduced dose images, as were used in this study [ 15 , 39 ].…”

Section: Methodsmentioning

confidence: 99%

Quantitative imaging analysis detects subtle airway abnormalities in symptomatic military deployers

et al. 2022

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Background Exposure to inhalational hazards during post-9/11 deployment to Southwest Asia and Afghanistan puts military personnel at risk for respiratory symptoms and disease. Pulmonary function and qualitative chest high resolution computed tomography (HRCT) are often normal in “deployers” with persistent respiratory symptoms. We explored the utility of quantitative HRCT imaging markers of large and small airways abnormalities, including airway wall thickness, emphysema, and air trapping, in symptomatic deployers with clinically-confirmed lung disease compared to controls. Methods Chest HRCT images from 45 healthy controls and 82 symptomatic deployers with asthma, distal lung disease or both were analyzed using Thirona Lung quantification software to calculate airway wall thickness (by Pi10), emphysema (by percentage of lung volume with attenuation < -950 Hounsfield units [LAA%-950]), and three parameters of air trapping (expiratory/inspiratory total lung volume and mean lung density ratios, and LAA%-856). SAS v.9.4 was used to compare demographic and clinical characteristics between deployers and controls using Chi-Square, Fisher Exact or t-tests. Linear regression was used to assess relationships between pulmonary function and quantitative imaging findings. Results Gender and smoking status were not statistically significantly different between groups, but deployers were significantly younger than controls (42 vs 58 years, p < 0.0001), had higher body mass index (31 vs 28 kg/m2, p = 0.01), and had fewer total smoking pack-years (8 vs. 26, p = 0.007). Spirometric measures were not statistically significantly different between groups. Pi10 and LAA%-950 were significantly elevated in deployers compared to controls in unadjusted analyses, with the emphysema measure remaining significantly higher in deployers after adjustment for age, sex, smoking, BMI, and expiratory total lung volume. Air trapping parameters were more common in control images, likely due to differences in age and smoking between groups. Among deployers, LAA%-950 and Pi10 were significantly correlated with spirometric markers of obstruction based on ratio of forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) and/or percent predicted FEV1. Conclusions Quantitative chest HRCT imaging analysis identifies emphysema in deployers with asthma and distal lung disease, and may be useful in detecting and monitoring deployment-related lung disease in a population where spirometry is typically normal.

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“…𝑣 2 is the noise variance in the equation above and was set according to the global noise index measured from the input data using the method described in [10].…”

Section: Physics-based Harmonizermentioning

confidence: 99%

“…It causes a decrease in respiratory lung function and shortness of breath, which gets worse with activity. The presence and severity of emphysema are associated with physiologic impairment, risk of exacerbation of COPD, and mortality [2]. Computed tomography (CT) has been an important screening tool for non-invasive disease assessment.…”

Section: Introductionmentioning

confidence: 99%

CT-HARMONICA: physics-based CT harmonization for reliable lung density quantification

Sotoudeh-Paima¹,

Samei²,

Abadi³

2023

Medical Imaging 2023: Computer-Aided Diagnosis

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Pulmonary emphysema is a form of Chronic Obstructive Pulmonary Disease (COPD) and a chronic lung condition that results in a breakdown of alveoli walls. Quantitative Computed Tomography (CT) is increasingly used to assess the presence or progression of emphysema. CT quantifications are affected by the acquisition protocols and scanner makes and models. This variability is a major concern for cross-sectional and longitudinal disease characterizations with largescale, multi-institutional datasets. Therefore, CT images need to be harmonized to reflect the patient condition and not the attributes of the imaging systems. The purpose of this study was to develop a physics-based harmonization framework that transforms CT images to a reference quality index (iso resolution and noise conditions) enabling robust emphysema quantifications across varied CT conditions. The harmonizer was developed using a virtual imaging trial (VIT) platform taking advantage of ground truth knowledge and control over CT parameters in VIT. The developed harmonizer was applied to clinical data from the COPDGene dataset to demonstrate its clinical utility. The established imaging biomarkers of "LAA-950" and "Perc15" were selected for emphysema quantifications. Results demonstrated that the harmonizer improved the quantification performance by reducing the bias in "LAA-950" from 7.03 (𝐶𝐼: [6.38, 7.68]) to 0.14 (𝐶𝐼: [0.08, 0.20]) after matching for kernel and from 2.48 (𝐶𝐼: [2.21, 2.76]) to −0.34 (𝐶𝐼: [−0.48, −0.20]) after matching for noise settings on the COPDGene dataset. This developed harmonization framework provides robust emphysema quantifications, enabling objective disease characterizations in large-scale, multi-center, and longitudinal studies.

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Comparison of CT Lung Density Measurements between Standard Full-Dose and Reduced-Dose Protocols

Cited by 15 publications

References 29 publications

Findings on High Resolution Computed Tomography in Symptomatic Veterans with Deployment-Related Lung Disease

Findings on High Resolution Computed Tomography in Symptomatic Veterans with Deployment-Related Lung Disease

Quantitative imaging analysis detects subtle airway abnormalities in symptomatic military deployers

CT-HARMONICA: physics-based CT harmonization for reliable lung density quantification

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