RT Journal Article
SR Electronic
T1 Direct In Vivo MRI Discrimination of Brain Stem Nuclei and Pathways
JF American Journal of Neuroradiology
JO Am. J. Neuroradiol.
FD American Society of Neuroradiology
SP 777
OP 784
DO 10.3174/ajnr.A6542
VO 41
IS 5
A1 T.M. Shepherd
A1 B. Ades-Aron
A1 M. Bruno
A1 H.M. Schambra
A1 M.J. Hoch
YR 2020
UL http://www.ajnr.org/content/41/5/777.abstract
AB BACKGROUND AND PURPOSE: The brain stem is a complex configuration of small nuclei and pathways for motor, sensory, and autonomic control that are essential for life, yet internal brain stem anatomy is difficult to characterize in living subjects. We hypothesized that the 3D fast gray matter acquisition T1 inversion recovery sequence, which uses a short inversion time to suppress signal from white matter, could improve contrast resolution of brain stem pathways and nuclei with 3T MR imaging.MATERIALS AND METHODS: After preliminary optimization for contrast resolution, the fast gray matter acquisition T1 inversion recovery sequence was performed in 10 healthy subjects (5 women; mean age, 28.8 ± 4.8 years) with the following parameters: TR/TE/TI = 3000/2.55/410 ms, flip angle = 4°, isotropic resolution = 0.8 mm, with 4 averages (acquired separately and averaged outside k-space to reduce motion; total scan time = 58 minutes). One subject returned for an additional 5-average study that was combined with a previous session to create a highest quality atlas for anatomic assignments. A 1-mm isotropic resolution, 12-minute version, proved successful in a patient with a prior infarct.RESULTS: The fast gray matter acquisition T1 inversion recovery sequence generated excellent contrast resolution of small brain stem pathways in all 3 planes for all 10 subjects. Several nuclei could be resolved directly by image contrast alone or indirectly located due to bordering visualized structures (eg, locus coeruleus and pedunculopontine nucleus).CONCLUSIONS: The fast gray matter acquisition T1 inversion recovery sequence has the potential to provide imaging correlates to clinical conditions that affect the brain stem, improve neurosurgical navigation, validate diffusion tractography of the brain stem, and generate a 3D atlas for automatic parcellation of specific brain stem structures.FGATIRfast gray matter acquisition T1 inversion recovery