Abstract
The signal acquired in sodium (23Na) MR imaging is proportional to the concentration of sodium in a voxel, and it is possible to convert between the two using external calibration phantoms. Postprocessing, and subsequent analysis, of sodium renal images is a simple task that can be performed with readily available software. Here we describe the process of conversion between sodium signal and concentration, estimation of the corticomedullary sodium gradient and the procedure used for quadrupolar relaxation analysis.This chapter is based upon work from the COST Action PARENCHIMA, a community-driven network funded by the European Cooperation in Science and Technology (COST) program of the European Union, which aims to improve the reproducibility and standardization of renal MRI biomarkers. This analysis protocol chapter is complemented by two separate chapters describing the basic concept and experimental procedure.
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References
- Milani B, Ansaloni A, Sousa-Guimaraes S et al (2017) Reduction of cortical oxygenation in chronic kidney disease: evidence obtained with a new analysis method of blood oxygenation level-dependent magnetic resonance imaging. Nephrol Dial Transplant 32(12):2097–2105 doi: 10.1093/ndt/gfw362. [DOI] [PubMed]
- Mikheev A, Lim RP (2016) A semi-automated “blanket” method for renal segmentation from non-contrast T1-weighted MR images. MAGMA 29:197–206 doi: 10.1007/s10334-015-0504-5. [DOI] [PMC free article] [PubMed]
- Gatzeva-topalova PZ, Warner LR, Pardi A, Carlos M (2011) Quantitative sodium imaging with a flexible twisted projection pulse sequence. Magn Reson Med 18:1492–1501 doi: 10.1002/mrm.22381. [DOI] [PMC free article] [PubMed]
- Morrell GR, Schabel MC (2010) An analysis of the accuracy of magnetic resonance flip angle measurement methods. Phys Med Biol 55:6157–6174 doi: 10.1088/0031-9155/55/20/008. [DOI] [PubMed]
- Saikia TC (1964) Composition of the renal cortex and medulla of rats during water diuresis and antidiuresis. J Clin Invest 51:1145–1151
