title: Ventilation-perfusion ratio of signal intensity in human lung using oxygen-enhanced and arterial spin labeling techniques.
abstract: This study investigates the distribution of ventilation-perfusion (V/Q) signal intensity (SI) ratios using oxygen-enhanced and arterial spin labeling (ASL) techniques in the lungs of 10 healthy volunteers. Ventilation and perfusion images were simultaneously acquired using the flow-sensitive alternating inversion recovery (FAIR) method as volunteers alternately inhaled room air and 100% oxygen. Images of the T(1) distribution were calculated for five volunteers for both selective (T(1f)) and nonselective (T(1)) inversion. The average T(1) was 1360 ms +/- 116 ms, and the average T(1f) was 1012 ms +/- 112 ms, yielding a difference that is statistically significant (P < 0.002). Excluding large pulmonary vessels, the average V/Q SI ratios were 0.355 +/- 0.073 for the left lung and 0.371 +/- 0.093 for the right lung, which are in agreement with the theoretical V/Q SI ratio. Plots of the V/Q SI ratio are similar to the logarithmic normal distribution obtained by multiple inert gas elimination techniques, with a range of ratios matching ventilation and perfusion. This MRI V/Q technique is completely noninvasive and does not involve ionized radiation. A limitation of this method is the nonsimultaneous acquisition of perfusion and ventilation data, with oxygen administered only for the ventilation data.
authors.affiliation: Department of Radiology, Evanston Hospital, Evanston Northwestern Healthcare, Illinois, USA. vmai@enh.org
authors.forename: Vu M
authors.initials: VM
authors.lastname: Mai
authors.forename: Benjamin
authors.initials: B
authors.lastname: Liu
authors.forename: Jason A
authors.initials: JA
authors.lastname: Polzin
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Saban
authors.initials: S
authors.lastname: Kurucay
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Bankier
authors.forename: Jack
authors.initials: J
authors.lastname: Knight-Scott
authors.forename: Priti
authors.initials: P
authors.lastname: Madhav
authors.forename: Robert R
authors.initials: RR
authors.lastname: Edelman
authors.forename: Qun
authors.initials: Q
authors.lastname: Chen
mesh_terms: D000328:Adult; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008168:Lung / Q000033:anatomy & histology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D010100:Oxygen; D011652:Pulmonary Circulation; D013113:Spin Labels; D014692:Ventilation-Perfusion Ratio
chemical_list: D013113:Spin Labels; D010100:Oxygen