@article {473081,
	title = {Computed Tomographic Measures of Pulmonary Vascular Morphology in Smokers and Their Clinical Implications.},
	journal = {American journal of respiratory and critical care medicineAmerican journal of respiratory and critical care medicine},
	volume = {188},
	year = {2013},
	month = {Jul 15},
	pages = {231-239},
	abstract = {Rationale: Angiographic investigation suggests that pulmonary vascular remodeling in smokers is characterized by distal pruning of the blood vessels. Objectives: Using volumetric computed tomography scans of the chest we sought to quantitatively evaluate this process and assess its clinical associations. Methods: Pulmonary vessels were automatically identified, segmented, and measured. Total blood vessel volume (TBV) and the aggregate vessel volume for vessels less than 5 mm(2) (BV5) were calculated for all lobes. The lobe-specific BV5 measures were normalized to the TBV of that lobe and the nonvascular tissue volume (BV5/T(issue)V) to calculate lobe-specific BV5/TBV and BV5/T(issue)V ratios. Densitometric measures of emphysema were obtained using a Hounsfield unit threshold of -950 (\%LAA-950). Measures of chronic obstructive pulmonary disease severity included single breath measures of diffusing capacity of carbon monoxide, oxygen saturation, the 6-minute-walk distance, St George{\textquoteright}s Respiratory Questionnaire total score (SGRQ), and the body mass index, airflow obstruction, dyspnea, and exercise capacity (BODE) index. Measurements and Main Results: The \%LAA-950 was inversely related to all calculated vascular ratios. In multivariate models including age, sex, and \%LAA-950, lobe-specific measurements of BV5/TBV were directly related to resting oxygen saturation and inversely associated with both the SGRQ and BODE scores. In similar multivariate adjustment lobe-specific BV5/T(issue)V ratios were inversely related to resting oxygen saturation, diffusing capacity of carbon monoxide, 6-minute-walk distance, and directly related to the SGRQ and BODE. Conclusions: Smoking-related chronic obstructive pulmonary disease is characterized by distal pruning of the small blood vessels (\<5 mm(2)) and loss of tissue in excess of the vasculature. The magnitude of these changes predicts the clinical severity of disease.},
	author = {San Jose Est{\'e}par, Ra{\'u}l and Kinney, Gregory L and Black-Shinn, Jennifer L and Bowler, Russell P and Kindlmann, Gordon L and Ross, James C and Kikinis, Ron and Han, MeiLan K and Come, Carolyn E and Diaz, Alejandro A and Cho, Michael H and Hersh, Craig P and Schroeder, Joyce D and Reilly, John J and Lynch, David A and Crapo, James D and Wells, J Michael and Dransfield, Mark T and Hokanson, John E and Washko, George R and COPDGene Study}
}