Comprehensive MR imaging protocol for stroke management: Tissue sodium concentration as a measure of tissue viability in nonhuman primate studies andin clinical studies
Kr. Thulborn et al., Comprehensive MR imaging protocol for stroke management: Tissue sodium concentration as a measure of tissue viability in nonhuman primate studies andin clinical studies, RADIOLOGY, 213(1), 1999, pp. 156-166
Citations number
69
Categorie Soggetti
Radiology ,Nuclear Medicine & Imaging","Medical Research Diagnosis & Treatment
PURPOSE: To investigate sodium magnetic resonance (MR) imaging for monitori
ng tissue viability in stroke.
MATERIALS AND METHODS: A comprehensive MR imaging protocol used to measure
apparent diffusion coefficient and perfusion parameters was extended to inc
lude sodium imaging. Tissue sodium concentration was estimated by using a t
wo-compartment model. This protocol lasted less than 45 minutes. These para
meters were followed over the first 6 hours in a nonhuman primate model (n
= 2) of acute embolic stroke without or with thrombolytic therapy. This pro
tocol was used in patients in whom acute (<24 hours, n = 11) or nonacute (g
reater than or equal to 24 hours, n = 31) stroke was ultimately confirmed.
RESULTS: The animal model showed abnormal diffusion and perfusion parameter
s in the lesion immediately after embolization, and these remained abnormal
for over 6 hours. Tissue sodium concentration increased with time (5.7 mmo
l/L/h) unless halted with thrombolytic therapy. Regions with sodium concent
rations over 70 mmol/L were histochemically verified as being infarcted. In
patients in whom stroke older than 6 hours was clinically confirmed, sodiu
m concentrations over 70 mmol/L were found in the appropriate brain regions
.
CONCLUSION: Tissue sodium concentration provides a sensitive measure of tis
sue viability that is complementary to the diagnostic role of diffusion and
perfusion imaging for ischemic insult.