Clinical and Micro-CT Imaging of Normal and Emphysematous Lungs
The background image was obtained using threedimensional, micro-computed tomography (micro-CT) on a lung specimen from a normal donor. Airways and blood vessels are shown penetrating alveolar ducts and alveoli. Imaging was performed at 8-μm isotropic resolution (McDonough JE, Yuan R, Suzuki M, et al. Smallairway obstruction and emphysema in chronic obstructive pulmonary disease. N Engl J Med. 2011;365(17):1567–1575. PMCID: PMC3238466). The clinical CT images in the insets are still frames captured from the corresponding online video, which can be accessed by scanning the adjacent QR code. The top image, a maximum-intensity projection of a reformatted coronal section, shows contrast-enhanced pulmonary vasculature. The bottom image, a volume rendering of a similar reformatted coronal section using inverted gray scale, reveals the airways.
The initial portion of the video, comprised of a coronal view from a contrast-enhanced chest CT scan obtained from a normal, 25-year-old woman, shows volume rendering of the bony thorax and pulmonary vasculature. The video transitions to volume rendering of the lungs, trachea, and bronchi. Shown subsequently is a rotating tomographic section of the distal airways. A red box in the section indicates the general location from which a lung specimen was obtained from a separate, normal donor for micro-CT imaging. The last segment of this portion of the video shows rectangular volume rendering of the specimen, which then transitions to a rotating tomographic depiction. Blood vessels (solid arrow), alveolar ducts (dashed arrow), and alveoli (dotted arrow) are identified. The second portion of the video demonstrates an unenhanced CT scan from a 63-year-old female lung transplant recipient who had severe COPD. The patient's chest x-ray is shown on the left and axial CT images on the right. The red box indicates the location from which a specimen was obtained from the explanted emphysematous lung for micro-CT imaging. The micro-CT segment in the video includes rectangular volume rendering of the emphysematous lung specimen and, subsequently, a rotating tomographic section of the tissue sample. Loss of alveolar structure is evident. Blood vessels (solid arrow), alveolar ducts (dashed arrow), and alveoli (dotted arrow) are noted. In this specimen, blood vessels are filled with residual blood.
Images courtesy of James C. Hogg, MD, PhD, John E. McDonough, PhD (both from the University of British Columbia), Joel D. Cooper, MD, Warren B. Gefter, MD, Michael A. Grippi, MD, Pablo G. Sanchez, MD, Drew A. Torigian, MD, and Alexander C. Wright, PhD (all from the University of Pennsylvania).