Fast 3D (1)H MRSI of the corticospinal tract in pediatric brain.
OBJECTIVE
To develop a (1)H magnetic resonance spectroscopic imaging (MRSI) sequence that can be used to image infants/children at 3T and by combining it with diffusion tensor imaging (DTI) tractography, extract relevant metabolic information corresponding to the corticospinal tract (CST).


METHODS
A fast 3D MRSI sequence was developed for pediatric neuroimaging at 3T using spiral k-space readout and dual band RF pulses (32 x 32 x 8 cm field of view [FOV], 1 cc iso-resolution, TR/TE = 1500/130, 6:24 minute scan). Using DTI tractography to identify the motor tracts, spectra were extracted from the CSTs and quantified. Initial data from infants/children with suspected motor delay (n = 5) and age-matched controls (n = 3) were collected and N-acetylaspartate (NAA) ratios were quantified.


RESULTS
The average signal-to-noise ratio of the NAA peak from the studies was approximately 22. Metabolite profiles were successfully acquired from the CST by using DTI tractography. Decreased NAA ratios in those with motor delay compared to controls of approximately 10% at the CST were observed.


CONCLUSIONS
A fast and robust 3D MRSI technique targeted for pediatric neuroimaging has been developed. By combining with DTI tractography, metabolic information from the CSTs can be retrieved and estimated. By combining DTI and 3D MRSI, spectral information from various tracts can be obtained and processed.
Kim
Dong-Hyun
DH
School of Electrical and Electronic Engineering, Yonsei University, Seoul, Korea. donghyunkim@yonsei.ac.kr
Gu
Meng
M
Cunningham
Charles
C
Chen
Albert
A
Baumer
Fiona
F
Glenn
Orit A
OA
Vigneron
Daniel B
DB
Spielman
Daniel Mark
DM
Barkovich
Anthony James
AJ
D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000032:analysis; D002540:Cerebral Cortex / Q000378:metabolism* / Q000473:pathology*; D002675:Child, Preschool; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D007223:Infant; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D009069:Movement Disorders / Q000378:metabolism* / Q000473:pathology*; D010372:Pediatrics / Q000379:methods; D011522:Protons; D011712:Pyramidal Tracts / Q000378:metabolism* / Q000473:pathology*
D011522:Protons; D001224:Aspartic Acid; C000179:N-acetylaspartate