Quantitative computed tomography of the lungs and airways in healthy nonsmoking adults
Jordan Alexander Zach, John D Newell Jr, Joyce Schroeder, James R Murphy, Douglas Curran-Everett, Eric A Hoffman, Philip M Westgate, MeiLan K Han, Edwin K Silverman, James D Crapo, David A Lynch, COPDGene Investigators, Jeffrey Curtis, Ella Kazerooni, Nicola Hanania, Philip Alapat, Venkata Bandi, Kalpalatha Guntupalli, Elizabeth Guy, Antara Mallampalli, Charles Trinh, Mustafa Atik, Dawn DeMeo, Craig Hersh, George Washko, Francine Jacobson, Graham Barr, Byron Thomashow, John Austin, Neil MacIntyre Jr, Lacey Washington, H Page McAdams, Richard Rosiello, Timothy Bresnahan, Charlene McEvoy, Joseph Tashjian, Robert Wise, Nadia Hansel, Robert Brown, Gregory Diette, Richard Casaburi, Janos Porszasz, Hans Fischer, Matt Budoff, Amir Sharafkhaneh, Charles Trinh, Hirani Kamal, Roham Darvishi, Dennis Niewoehner, Tadashi Allen, Quentin Anderson, Kathryn Rice, Marilyn Foreman, Gloria Westney, Eugene Berkowitz, Russell Bowler, Adam Friedlander, David Lynch, Joyce Schroeder, John Newell Jr, Gerard Criner, Victor Kim, Nathaniel Marchetti, Aditi Satti, A James Mamary, Robert Steiner, Chandra Dass, William Bailey, Mark Dransfield, Hrudaya Nath, Joe Ramsdell, Paul Friedman, Geoffrey McLennan, Edwin J R van Beek, Brad Thompson, Dwight Look, Fernando Martinez, MeiLan Han, Ella Kazerooni, Christine Wendt, Tadashi Allen, Frank Sciurba, Joel Weissfeld, Carl Fuhrman, Jessica Bon, Antonio Anzueto, Sandra Adams, Carlos Orozco, Mario Ruiz, James Crapo, Edwin Silverman, Barry Make, Elizabeth Regan, Sarah Moyle, Douglas Stinson, Terri Beaty, Barbara Klanderman, Nan Laird, Christoph Lange, Michael Cho, Stephanie Santorico, John Hokanson, Dawn DeMeo, Nadia Hansel, Craig Hersh, Jacqueline Hetmanski, Tanda Murray, David Lynch, Joyce Schroeder, John Newell Jr, John Reilly, Harvey Coxson, Philip Judy, Eric Hoffman, George Washko, Raul San Jose Estepar, James Ross, Rebecca Leek, Jordan Zach, Alex Kluiber, Jered Sieren, Heather Baumhauer, Verity McArthur, Dzimitry Kazlouski, Tanya Mann, Anastasia Rodionova, Robert Jensen, Homayoon Farzadegan, Stacey Meyerer, Shivam Chandan, Samantha Bragan, James Murphy, Douglas Everett, Carla Carla, Ruthie Knowles, Amber Powell, Joe Piccoli, Maura Robinson, Margaret Forbes, Martina Wamboldt, John Hokanson, Marci Sontag, Jennifer Black-Shinn, Gregory Kinney, Jordan Alexander Zach, John D Newell Jr, Joyce Schroeder, James R Murphy, Douglas Curran-Everett, Eric A Hoffman, Philip M Westgate, MeiLan K Han, Edwin K Silverman, James D Crapo, David A Lynch, COPDGene Investigators, Jeffrey Curtis, Ella Kazerooni, Nicola Hanania, Philip Alapat, Venkata Bandi, Kalpalatha Guntupalli, Elizabeth Guy, Antara Mallampalli, Charles Trinh, Mustafa Atik, Dawn DeMeo, Craig Hersh, George Washko, Francine Jacobson, Graham Barr, Byron Thomashow, John Austin, Neil MacIntyre Jr, Lacey Washington, H Page McAdams, Richard Rosiello, Timothy Bresnahan, Charlene McEvoy, Joseph Tashjian, Robert Wise, Nadia Hansel, Robert Brown, Gregory Diette, Richard Casaburi, Janos Porszasz, Hans Fischer, Matt Budoff, Amir Sharafkhaneh, Charles Trinh, Hirani Kamal, Roham Darvishi, Dennis Niewoehner, Tadashi Allen, Quentin Anderson, Kathryn Rice, Marilyn Foreman, Gloria Westney, Eugene Berkowitz, Russell Bowler, Adam Friedlander, David Lynch, Joyce Schroeder, John Newell Jr, Gerard Criner, Victor Kim, Nathaniel Marchetti, Aditi Satti, A James Mamary, Robert Steiner, Chandra Dass, William Bailey, Mark Dransfield, Hrudaya Nath, Joe Ramsdell, Paul Friedman, Geoffrey McLennan, Edwin J R van Beek, Brad Thompson, Dwight Look, Fernando Martinez, MeiLan Han, Ella Kazerooni, Christine Wendt, Tadashi Allen, Frank Sciurba, Joel Weissfeld, Carl Fuhrman, Jessica Bon, Antonio Anzueto, Sandra Adams, Carlos Orozco, Mario Ruiz, James Crapo, Edwin Silverman, Barry Make, Elizabeth Regan, Sarah Moyle, Douglas Stinson, Terri Beaty, Barbara Klanderman, Nan Laird, Christoph Lange, Michael Cho, Stephanie Santorico, John Hokanson, Dawn DeMeo, Nadia Hansel, Craig Hersh, Jacqueline Hetmanski, Tanda Murray, David Lynch, Joyce Schroeder, John Newell Jr, John Reilly, Harvey Coxson, Philip Judy, Eric Hoffman, George Washko, Raul San Jose Estepar, James Ross, Rebecca Leek, Jordan Zach, Alex Kluiber, Jered Sieren, Heather Baumhauer, Verity McArthur, Dzimitry Kazlouski, Tanya Mann, Anastasia Rodionova, Robert Jensen, Homayoon Farzadegan, Stacey Meyerer, Shivam Chandan, Samantha Bragan, James Murphy, Douglas Everett, Carla Carla, Ruthie Knowles, Amber Powell, Joe Piccoli, Maura Robinson, Margaret Forbes, Martina Wamboldt, John Hokanson, Marci Sontag, Jennifer Black-Shinn, Gregory Kinney
Abstract
Objectives: The purposes of this study were to evaluate the reference range of quantitative computed tomography (QCT) measures of lung attenuation and airway parameter measurements in healthy nonsmoking adults and to identify sources of variation in those measures and possible means to adjust for them.
Materials and methods: Within the COPDGene study, 92 healthy non-Hispanic white nonsmokers (29 men, 63 women; mean [SD] age, 62.7 [9.0] years; mean [SD] body mass index [BMI], 28.1 [5.1] kg/m(2)) underwent volumetric computed tomography (CT) at full inspiration and at the end of a normal expiration. On QCT analysis (Pulmonary Workstation 2, VIDA Diagnostics), inspiratory low-attenuation areas were defined as lung tissue with attenuation values -950 Hounsfield units or less on inspiratory CT (LAA(I-950)). Expiratory low-attenuation areas were defined as lung tissue -856 Hounsfield units or less on expiratory CT (LAA(E-856)). We used simple linear regression to determine the impact of age and sex on QCT parameters and multiple regression to assess the additional impact of total lung capacity and functional residual capacity measured by CT (TLC(CT) and FRC(CT)), scanner type, and mean tracheal air attenuation. Airways were evaluated using measures of airway wall thickness, inner luminal area, wall area percentage (WA%), and standardized thickness of an airway with inner perimeter of 10 mm (Pi10).
Results: Mean (SD) %LAA(I-950) was 2.0% (2.7%), and mean (SD) %LAA(E-856) was 9.2% (6.8%). Mean (SD) %LAA(I-950) was 3.6% (3.2%) in men, compared with 1.3% (2.0%) in women (P < 0.001). The %LAA(I-950) did not change significantly with age (P = 0.08) or BMI (P = 0.52). %LAA(E-856) did not show any independent relationship with age (P = 0.33), sex (P = 0.70), or BMI (P = 0.32). On multivariate analysis, %LAA(I-950) showed a direct relationship to TLC(CT) (P = 0.002) and an inverse relationship to mean tracheal air attenuation (P = 0.003), and %LAA(E-856) was related to age (P = 0.001), FRC(CT) (P = 0.007), and scanner type (P < 0.001). Multivariate analysis of segmental airways showed that inner luminal area and WA% were significantly related to TLC(CT) (P < 0.001) and age (0.006). Moreover, WA% was associated with sex (P = 0.05), axial pixel size (P = 0.03), and slice interval (P = 0.04). Lastly, airway wall thickness was strongly influenced by axial pixel size (P < 0.001).
Conclusions: Although the attenuation characteristics of normal lung differ by age and sex, these differences do not persist on multivariate analysis. Potential sources of variation in measurement of attenuation-based QCT parameters include depth of inspiration/expiration and scanner type. Tracheal air attenuation may partially correct variation because of scanner type. Sources of variation in QCT airway measurements may include age, sex, BMI, depth of inspiration, and spatial resolution.
Source: PubMed