A Three-Field Study of Cerebral Transverse Relaxation Rates in Vivo: Implications for Brain Iron Measurements

Ana Maria Oros-Peusquens¹, Miriam Rabea Kubach¹, Maija Laurila¹, N. Jon Shah^1,2

Relaxation times in pure water and their field dependence is well predicted by the Blombergen-Purcell-Pound theory; this dependence for typical MRI fields is negligible. Proton relaxation times in tissue are different from those of pure water and have a pronounced field dependence possibly due to micro-structural ferritin content, for example. We report a 3-field study of T2/T2* in vivo performed with the aim of providing quantitative information about transverse relaxation in a field range of 1.5T-4T. Further, we discriminate between the linear and quadratic dependence of T2/T2* on field strength and investigate the correlation between the rate increase in regions with clear a linear dependence and their estimated iron content. The relevance of this methodology to brain iron content measurements in vivo is discussed.