Journal of Applied Physiology, Vol 66, Issue 4 1905-1913, Copyright © 1989 by American Physiological Society

ARTICLES

Quantification of regional V/Q ratios in humans by use of PET. II. Procedure and normal values

C. G. Rhodes, S. O. Valind, L. H. Brudin, P. E. Wollmer, T. Jones, P. D. Buckingham and J. M. Hughes
Medical Research Council Cyclotron Unit, Royal Postgraduate Medical School, Hammersmith Hospital, London, United Kingdom.

Regional measurements of tissue isotope concentration, made using positron emission tomography (PET), allow tracer models to be used in a quantitative manner to provide topographic distributions of many structural and functional parameters, each derived for the same well-defined lung element. In this paper we describe a technique to measure regional ventilation-perfusion ratios (V/Q), in absolute units, by use of PET and the continuous intravenous infusion of an inert gas isotope, 13N, and report on measurements made in 12 normal subjects (4 smokers). Data were obtained from a single lung section (slice thickness, 1.7 cm full width at half-maximum response to a line source) at the level of the right ventricle in the supine posture during quiet breathing. For the 12 subjects, volume-weighted mean values of V/Q, averaged over individual right and left lung fields, ranged from 0.50 to 1.29. Analysis of these means showed no difference between lungs: right, 0.80 +/- 0.23 SD; left, 0.76 +/- 0.20 SD. Topographically, a systematic fall of V/Q in the ventrodorsal direction was observed in eight of the subjects (mean ventrodorsal difference 0.39, range 0.19-0.90), whereas two showed a clear increase toward dependent lung regions (range 0.16-0.26). Seven of the subjects with a falling ventrodorsal V/Q gradient also exhibited discrete regions of low V/Q at the dorsal lung border. We conclude that, in normal subjects, ventilation and perfusion are generally well matched in the supine posture, but isolated mismatching often occurs in dependent lung regions.

This article has been cited by other articles:

				G. Musch, G. Bellani, M. F. Vidal Melo, R. S. Harris, T. Winkler, T. Schroeder, and J. G. Venegas Relation between Shunt, Aeration, and Perfusion in Experimental Acute Lung Injury Am. J. Respir. Crit. Care Med., February 1, 2008; 177(3): 292 - 300. [Abstract] [Full Text] [PDF]

				J. Petersson, A. Sanchez-Crespo, S. A. Larsson, and M. Mure Physiological imaging of the lung: single-photon-emission computed tomography (SPECT) J Appl Physiol, January 1, 2007; 102(1): 468 - 476. [Abstract] [Full Text] [PDF]

				R. S. Harris and D. P. Schuster Visualizing lung function with positron emission tomography J Appl Physiol, January 1, 2007; 102(1): 448 - 458. [Abstract] [Full Text] [PDF]

				G. Musch and J. G. Venegas Positron Emission Tomography Imaging of Regional Pulmonary Perfusion and Ventilation Proceedings of the ATS, December 1, 2005; 2(6): 522 - 527. [Abstract] [Full Text] [PDF]

				J. Petersson, A. Sanchez-Crespo, M. Rohdin, S. Montmerle, S. Nyren, H. Jacobsson, S. A. Larsson, S. G. E. Lindahl, D. Linnarsson, R. W. Glenny, et al. Physiological evaluation of a new quantitative SPECT method measuring regional ventilation and perfusion J Appl Physiol, March 1, 2004; 96(3): 1127 - 1136. [Abstract] [Full Text] [PDF]

				M. F. Vidal Melo, D. Layfield, R. S. Harris, K. O'Neill, G. Musch, T. Richter, T. Winkler, A. J. Fischman, and J. G. Venegas Quantification of Regional Ventilation-Perfusion Ratios with PET J. Nucl. Med., December 1, 2003; 44(12): 1982 - 1991. [Abstract] [Full Text] [PDF]

				G. Musch, J. D. H. Layfield, R. S. Harris, M. F. V. Melo, T. Winkler, R. J. Callahan, A. J. Fischman, and J. G. Venegas Topographical distribution of pulmonary perfusion and ventilation, assessed by PET in supine and prone humans J Appl Physiol, November 1, 2002; 93(5): 1841 - 1851. [Abstract] [Full Text] [PDF]

				U. J. Schoepf, R. Bruening, H. Konschitzky, C. R. Becker, A. Knez, J. Weber, O. Muehling, P. Herzog, A. Huber, R. Haberl, et al. Pulmonary Embolism: Comprehensive Diagnosis by Using Electron-Beam CT for Detection of Emboli and Assessment of Pulmonary Blood Flow Radiology, December 1, 2000; 217(3): 693 - 700. [Abstract] [Full Text]

				S. M. Mijailovich, S. Treppo, and J. G. Venegas Effects of lung motion and tracer kinetics corrections on PET imaging of pulmonary function J Appl Physiol, April 1, 1997; 82(4): 1154 - 1162. [Abstract] [Full Text] [PDF]

				S. Treppo, S. M. Mijailovich, and J. G. Venegas Contributions of pulmonary perfusion and ventilation to heterogeneity in VA/Q measured by PET J Appl Physiol, April 1, 1997; 82(4): 1163 - 1176. [Abstract] [Full Text] [PDF]