. 2013 May 24;11:15. doi: 10.1186/1476-7120-11-15
Copyright © 2013 Petkow Dimitrow and Sorysz; licensee BioMed Central Ltd.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Figure 2.
Maximal gradient in supine position.