Heterogeneity of acute multiple sclerosis lesions on sodium (²³Na) MRI

Abstract

TSC is not only a sensitive marker of the severity of chronic tissue abnormalities in MS but is also highly sensitive to opening of the blood-brain barrier and vasogenic tissue oedema in contrast-enhancing lesions.

Sodium MRI of T1 High Signal Intensity in the Dentate Nucleus due to Gadolinium Deposition in Multiple Sclerosis

“…In stroke, a TSC increase was observed in the phase of extracellular edema and irreversible tissue disintegration, but not in the acute (potentially reversible) phase of ischemia . In MS studies, sodium increase was more pronounced in T1 hypointense than in T1 isointense lesions suggesting that increased sodium levels represent tissue destruction that is associated with an increased extracellular space . The highest sodium levels were found in acute contrast‐enhancing lesion, indicating that increased sodium levels are not only a marker of tissue integrity, but also of edematous water influx linked to blood‐brain‐barrier dysfunction .…”

“…23 Na MR imaging was performed with the following parameters: repetition time (TR) = 60 ms, echo time (TE) = .22 ms, flip angle (FA) = 80°, readout time of 15 ms, 3.6 mm isotropic resolution, and 12,000 projections resulting in a total measurement time of 12 minutes. A detailed protocol is described elsewhere . In all patients, an experienced reader identified the DN on fluid attenuated inversion recovery (FLAIR) images with a semiautomated assistance with the drawing tool of MRIcron (http://www.mccauslandcenter.sc.edu/mricro/mricron/).…”

“…Until today no negative clinical effects of gadolinium deposition in the DN have been reported; however, one could hypothesize whether gadolinium deposition has any neural tissue damage. Sodium ( 23 Na) MRI has recently been shown to be a very sensitive marker of tissue integrity detecting tissue abnormalities in multiple sclerosis (MS) associated with tissue loss and widening of the extracellular space in focal lesions and the normal appearing brain tissue . The high sodium concentration gradient of extracellular versus lower intracellular sodium indicates sensitively pathologies with increased extracellular water contributions .…”

“…Sodium ( 23 Na) MRI has recently been shown to be a very sensitive marker of tissue integrity detecting tissue abnormalities in multiple sclerosis (MS) associated with tissue loss and widening of the extracellular space in focal lesions and the normal appearing brain tissue. 11,12 The high sodium concentration gradient of extracellular versus lower intracellular sodium indicates sensitively pathologies with increased extracellular water contributions. 13 We used 23 Na MRI in an attempt to identify indications of abnormal tissue integrity in the T1 hyperintense DN of MS patients.…”

X‐nuclei imaging: Current state, technical challenges, and future directions

“…23 Na MRI can support the evaluation of treatment response especially concerning the neurodegenerative component. Additionally, recent studies indicate that 23 Na MRI could be used to monitor inflammatory processes …”