Serial triple quantum sodium MRI during non-human primate focal brain ischemia

Area of Science:

• Neuroimaging
• Medical Physics
• Neurology

Background:

• Focal brain ischemia, a critical neurological condition, requires timely and accurate diagnostic methods.
• Current MRI techniques may have limitations in early detection of ischemic changes.
• Sodium MRI offers potential for detecting cellular changes associated with ischemia.

Purpose of the Study:

• To evaluate the feasibility of triple quantum (TQ) sodium MRI for in vivo detection of focal brain ischemia.
• To assess the temporal changes in TQ sodium MRI signal intensity following induced ischemia in a nonhuman primate model.
• To compare TQ sodium MRI signal changes with single quantum (SQ) sodium MRI signal changes in the ischemic brain.

Main Methods:

• Induction of focal brain ischemia in nonhuman primates via occlusion of cerebral arteries.
• Acquisition of in vivo triple quantum (TQ) and single quantum (SQ) sodium MRI data.
• Registration of TQ sodium MRI data with anatomical proton MRI for anatomical localization.
• Statistical analysis of TQ sodium MRI signal intensity differences between ischemic and contralateral hemispheres.

Main Results:

• A statistically significant increase (P < 0.001) in TQ sodium MRI signal intensity was observed in the ischemic hemisphere compared to the contralateral hemisphere.
• This TQ sodium MRI hyperintensity was detectable as early as 0.6 hours after ischemia onset.
• The observed hyperintensity localized to the anatomically defined ischemic cortex.
• Negligible changes were noted in the SQ sodium MRI signal intensity.

Conclusions:

• Triple quantum (TQ) sodium MRI is a viable technique for early in vivo detection of focal brain ischemia.
• TQ sodium MRI demonstrates increased signal intensity in the ischemic hemisphere shortly after onset.
• This method shows promise for improving the early diagnosis of stroke.