TY - JOUR
T1 - MRI-based assessment of acute effect of head-down tilt position on intracranial hemodynamics and hydrodynamics
AU - Ishida, Shota
AU - Miyati, Tosiaki
AU - Ohno, Naoki
AU - Hiratsuka, Shinnosuke
AU - Alperin, Noam
AU - Mase, Mitsuhito
AU - Gabata, Toshifumi
N1 - Funding Information:
This work was supported by JSPS KAKENHI Grant Number JP16K09013.
Publisher Copyright:
© 2017 International Society for Magnetic Resonance in Medicine.
PY - 2018/2
Y1 - 2018/2
N2 - Purpose: To quantify the acute effect of the head-down tilt (HDT) posture on intracranial hemodynamics and hydrodynamics. Materials and Methods: We evaluated the intracranial physiological parameters, blood flow-related parameters, and brain morphology in the HDT (–6° and –12°) and the horizontal supine (HS) positions. Seven and 15 healthy subjects were scanned for each position using 3.0 T magnetic resonance imaging system. The peak-to-peak intracranial volume change, the peak-to-peak cerebrospinal fluid (CSF) pressure gradient (PGp-p), and the intracranial compliance index were calculated from the blood and CSF flow determined using a cine phase-contrast technique. The brain volumetry was conducted using SPM12. The measurements were compared using the Wilcoxon signed-rank test or a paired t-test. Results: No measurements changed in the –6° HDT. The PGp-p and venous outflow of the internal jugular veins (IJVs) in the –12° HDT were significantly increased compared to the HS (P < 0.001 and P = 0.025, respectively). The cross-sectional areas of the IJVs were significantly larger (P < 0.001), and the maximum, minimum, and mean blood flow velocity of the IJVs were significantly decreased (P = 0.003, < 0.001, and = 0.001, respectively) in the –12° HDT. The mean blood flow velocities of the internal carotid arteries were decreased (P = 0.023). Neither position affected the brain volume. Conclusion: Pressure gradient and venous outflow were increased in accordance with the elevation of the intracranial pressure as an acute effect of the HDT. However, the CSF was not constantly shifted from the spinal canal to the cranium. Level of Evidence: 2. Technical Efficacy: Stage 1. J. Magn. Reson. Imaging 2018;47:565–571.
AB - Purpose: To quantify the acute effect of the head-down tilt (HDT) posture on intracranial hemodynamics and hydrodynamics. Materials and Methods: We evaluated the intracranial physiological parameters, blood flow-related parameters, and brain morphology in the HDT (–6° and –12°) and the horizontal supine (HS) positions. Seven and 15 healthy subjects were scanned for each position using 3.0 T magnetic resonance imaging system. The peak-to-peak intracranial volume change, the peak-to-peak cerebrospinal fluid (CSF) pressure gradient (PGp-p), and the intracranial compliance index were calculated from the blood and CSF flow determined using a cine phase-contrast technique. The brain volumetry was conducted using SPM12. The measurements were compared using the Wilcoxon signed-rank test or a paired t-test. Results: No measurements changed in the –6° HDT. The PGp-p and venous outflow of the internal jugular veins (IJVs) in the –12° HDT were significantly increased compared to the HS (P < 0.001 and P = 0.025, respectively). The cross-sectional areas of the IJVs were significantly larger (P < 0.001), and the maximum, minimum, and mean blood flow velocity of the IJVs were significantly decreased (P = 0.003, < 0.001, and = 0.001, respectively) in the –12° HDT. The mean blood flow velocities of the internal carotid arteries were decreased (P = 0.023). Neither position affected the brain volume. Conclusion: Pressure gradient and venous outflow were increased in accordance with the elevation of the intracranial pressure as an acute effect of the HDT. However, the CSF was not constantly shifted from the spinal canal to the cranium. Level of Evidence: 2. Technical Efficacy: Stage 1. J. Magn. Reson. Imaging 2018;47:565–571.
KW - brain morphology
KW - cerebral hemodynamics
KW - cerebrospinal fluid pressure gradient
KW - head-down tilt
KW - intracranial physiology
UR - http://www.scopus.com/inward/record.url?scp=85020104337&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85020104337&partnerID=8YFLogxK
U2 - 10.1002/jmri.25781
DO - 10.1002/jmri.25781
M3 - Article
C2 - 28577333
AN - SCOPUS:85020104337
VL - 47
SP - 565
EP - 571
JO - Journal of Magnetic Resonance Imaging
JF - Journal of Magnetic Resonance Imaging
SN - 1053-1807
IS - 2
ER -