Prospective longitudinal proton magnetic resonance spectroscopic imaging in adult traumatic brain injury.
OBJECTIVE
To investigate whether longitudinal magnetic resonance proton spectroscopic imaging (MRSI) demonstrates regional metabolite abnormalities after traumatic brain injury (TBI) that predict long-term neurologic outcome.


METHODS
Two-dimensional-MRSI (point resolved spectroscopy sequence [PRESS]; TR/TE = 3000/144 msec; 10 mm) was acquired prospectively in 42 adults with severe TBI through the level of the corpus callosum 7 +/- 4 days after injury. Measurements were repeated in 31 patients six to 12 months after injury. Regional and pooled (all regions combined) mean ratios were compared with control values and then used to predict long-term (six- to -12-month) neurologic outcome (good vs. poor) using a logistic regression model.


RESULTS
Initial pooled mean N-acetylaspartate (NAA) ratios were lower (P < 0.01) and choline (Cho)/creatine (Cr) ratios higher (P < 0.01) in all TBI patients compared to controls. Ratios from the corpus callosum region were affected most and predicted long-term dichotomized outcome with 83% accuracy. When repeated at six to 12 months after injury, pooled mean NAA/Cr remained lower (P = 0.03) and Cho/Cr remained higher (P = 0.01) in patients with poor outcomes.


CONCLUSIONS
The NAA/Cr ratio from the corpus callosum was most useful for outcome prediction. Chronic alterations of metabolite ratios are likely due to neuronal loss and glial proliferation long after injury.
Holshouser
Barbara A
BA
Department of Radiology, Loma Linda University School of Medicine, Loma Linda, California, USA. bholshouser@ahs.llumc.edu
Tong
Karen A
KA
Ashwal
Stephen
S
Oyoyo
Udochukwu
U
Ghamsary
Mark
M
Saunders
David
D
Shutter
Lori
L
D000293:Adolescent; D000328:Adult; D000368:Aged; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D001930:Brain Injuries / Q000175:diagnosis / Q000473:pathology*; D016022:Case-Control Studies; D003337:Corpus Callosum / Q000473:pathology; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009462:Neurology / Q000379:methods; D011522:Protons
D011522:Protons; D001224:Aspartic Acid; C000179:N-acetylaspartate