Quantitative BOLD response of the renal medulla to hyperoxic challenge at 1.5 T and 3.0 T
Article first published online: 31 JAN 2012
Copyright © 2012 John Wiley & Sons, Ltd.
NMR in Biomedicine
Volume 25, Issue 10, pages 1133–1138, October 2012
How to Cite
Donati, O. F., Nanz, D., Serra, A. L. and Boss, A. (2012), Quantitative BOLD response of the renal medulla to hyperoxic challenge at 1.5 T and 3.0 T. NMR Biomed., 25: 1133–1138. doi: 10.1002/nbm.2781
- Issue published online: 13 SEP 2012
- Article first published online: 31 JAN 2012
- Manuscript Revised: 23 DEC 2011
- Manuscript Accepted: 23 DEC 2011
- Manuscript Received: 23 SEP 2011
- BOLD imaging;
- hyperoxic challenge;
- renal medulla;
The aim of this study was to gage the magnitude of changes of the apparent renal medullary transverse relaxation time (ΔT2*) induced by inhalation of pure oxygen (O2) or carbogen (95% O2, 5% CO2) versus baseline breathing of room air. Eight healthy volunteers underwent 2D multi-gradient echo MR imaging at 1.5 T and 3.0 T. Parametrical T2* relaxation time maps were computed and average T2* was measured in regions of interest placed in the renal medulla and cortex. The largest T2* changes were measured in the renal medulla, with a relative ∆T2* of 33.8 ± 22.0% (right medulla) and 34.7 ± 17.6% (left medulla) as compared to room air for oxygen breathing (p > 0.01), and 53.8 ± 23.9% and 53.5 ± 33.9% (p < 0.01) for carbogen breathing, respectively at 3 T. At 1.5 T, the corresponding values were 13.7 ± 18.5% and 24.1 ± 17.1% (p < 0.01) for oxygen breathing and 23.9 ± 17.2% and 38.9 ± 37.6% (p < 0.01) for carbogen breathing. As a result, we showed that renal medullary T2* times responded strongly to inhalation of hyperoxic gases, which may be attributed to the hypoxic condition of the medulla and subsequent reduction in deoxyhemoglobin. Copyright © 2012 John Wiley & Sons, Ltd.