Investigation of prolonged hypobaric hypoxia-induced change in rat brain using T2 relaxometry and diffusion tensor imaging at 7T

Long‐term sequelae of hippocampal lesions in patients with transient global amnesia: A multiparametric MRI study

“…In another aspect, an increase of brain water content was associated with an increase of brain iron. For example, in rats exposed to a simulated hypobaric hypoxia, a decreased ADC was observed in the hippocampus, which depicts iron deposition …”

“…For example, in rats exposed to a simulated hypobaric hypoxia, a decreased ADC was observed in the hippocampus, which depicts iron deposition. 20 An acute increase in magnetic susceptibility during the onset of TGA may be due to the increase of blood deoxyhemoglobin. Deoxyhemoglobin is paramagnetic.…”

“…18 Moreover, an increase of brain water content has been shown to be associated with an increase of brain iron. 19,20 Recently, quantitative susceptibility mapping (QSM) has been used to analyze magnetic susceptibility, which has been shown to correlate well with iron concentration in gray matter. 21 Accordingly, QSM is a useful technique for noninvasive measurement of brain iron concentration.…”

A Multicenter Preclinical MRI Study: Definition of Rat Brain Relaxometry Reference Maps

“…They show that T1 relaxation time increases with magnetic field while T2 relaxation time decreases (de Graaf et al, 2006, Wright et al, 2008, van de Ven et al, 2007. Some values have been reported in the literature for few brain regions (Barbier et al, 2005, Behroozi et al, 2018, Cremillieux et al, 1998, Del Bigio et al, 2011, Gigliucci et al, 2014, Koundal et al, 2015, Liachenko and Ramu, 2017, Suleymanova et al, 2014, but no consensus has been reached yet about values of reference for specific rat brain regions. To define such reference maps, a large number of brain structures or regions should be considered and a sufficient number of animals should be included to reflect inter-individual variability.…”

In vivo measurement of T1 and T2 relaxation times in awake pigeon and rat brains at 7T

“…In the present 7T study, we have used a CPMG sequence with 10.73‐ms interpulse interval. Studies in humans and animals have reported that T 2 values measured in brain tissue using CPMG sequences are dependent on the refocusing interval due to dynamic dephasing caused by the strong magnetic field gradients created by deoxygenated blood in veins and eventual iron/ferritin deposits. Therefore, it is important to keep in mind that the T 2 values reported in the present study correspond to the so‐called apparent T 2 , as defined in .…”