PMID- 27635467
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20180719
LR  - 20180719
IS  - 1096-0856 (Electronic)
IS  - 1090-7807 (Linking)
VI  - 272
DP  - 2016 Nov
TI  - Characterization of spinal cord white matter by suppressing signal from hindered 
      space. A Monte Carlo simulation and an ex vivo ultrahigh-b diffusion-weighted 
      imaging study.
PG  - 53-59
LID - S1090-7807(16)30162-8 [pii]
LID - 10.1016/j.jmr.2016.09.001 [doi]
AB  - Signal measured from white matter in diffusion-weighted imaging is difficult to 
      interpret because of the heterogeneous structure of white matter. 
      Characterization of the white matter will be straightforward if the signal 
      contributed from the hindered space is suppressed and purely restricted signal is 
      analyzed. In this study, a Monte Carlo simulation (MCS) of water diffusion in 
      white matter was performed to understand the behavior of the diffusion-weighted 
      signal in white matter. The signal originating from the hindered space of an 
      excised pig cervical spinal cord white matter was suppressed using the 
      ultrahigh-b radial diffusion-weighted imaging. A light microscopy image of a 
      section of white matter was obtained from the excised pig cervical spinal cord 
      for the MCS. The radial diffusion-weighted signals originating from each of the 
      intra-axonal, extra-axonal, and total spaces were studied using the MCS. The MCS 
      predicted that the radial diffusion-weighted signal remains almost constant in 
      the intra-axonal space and decreases gradually to about 2% of its initial value 
      in the extra-axonal space when the b-value is increased to 30,000s/mm(2). The MCS 
      also revealed that the diffusion-weighted signal for a b-value greater than 
      20,000s/mm(2) is mostly from the intra-axonal space. The decaying behavior of the 
      signal-b curve obtained from ultrahigh-b diffusion-weighted imaging 
      (b(max) approximately 30,000s/mm(2)) of the excised pig cord was very similar to the decaying 
      behavior of the total signal-b curve synthesized in the MCS. A mono-exponential 
      plus constant fitting of the signal-b curve obtained from a white matter pixel 
      estimated the values of constant fraction and apparent diffusion coefficient of 
      decaying fraction as 0.32+/-0.05 and (0.16+/-0.01)x10(-3)mm(2)/s, respectively, which 
      agreed well with the results of the MCS. The signal measured in the ultrahigh-b 
      region (b>20,000s/mm(2)) is mostly from the restricted (intra-axonal) space. 
      Integrity and intactness of the axons can be evaluated by assessing the remaining 
      signal in the ultrahigh-b region.
CI  - Published by Elsevier Inc.
FAU - Sapkota, Nabraj
AU  - Sapkota N
AD  - Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, 
      UT, USA; Department of Physics and Astronomy, University of Utah, Salt Lake City, 
      UT, USA.
FAU - Yoon, Sook
AU  - Yoon S
AD  - Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, 
      UT, USA.
FAU - Thapa, Bijaya
AU  - Thapa B
AD  - Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, 
      UT, USA; Department of Physics and Astronomy, University of Utah, Salt Lake City, 
      UT, USA.
FAU - Lee, YouJung
AU  - Lee Y
AD  - Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, 
      UT, USA; Department of Radiology and Imaging Sciences, University of Utah, Salt 
      Lake City, UT, USA.
FAU - Bisson, Erica F
AU  - Bisson EF
AD  - Department of Neurosurgery, University of Utah, Salt Lake City, UT, USA.
FAU - Bowman, Beth M
AU  - Bowman BM
AD  - Department of Radiobiology, University of Utah, Salt Lake City, UT, USA.
FAU - Miller, Scott C
AU  - Miller SC
AD  - Department of Radiobiology, University of Utah, Salt Lake City, UT, USA.
FAU - Shah, Lubdha M
AU  - Shah LM
AD  - Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, 
      UT, USA.
FAU - Rose, John W
AU  - Rose JW
AD  - Department of Neurology, University of Utah, Salt Lake City, UT, USA.
FAU - Jeong, Eun-Kee
AU  - Jeong EK
AD  - Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, 
      UT, USA; Department of Radiology and Imaging Sciences, University of Utah, Salt 
      Lake City, UT, USA. Electronic address: ek.jeong@utah.edu.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, Non-P.H.S.
DEP - 20160904
PL  - United States
TA  - J Magn Reson
JT  - Journal of magnetic resonance (San Diego, Calif. : 1997)
JID - 9707935
OTO - NOTNLM
OT  - Diffusion-weighted imaging
OT  - High-b
OT  - Monte Carlo simulation
OT  - Spinal cord
OT  - Ultrahigh-b
OT  - White matter
EDAT- 2016/10/21 06:00
MHDA- 2016/10/21 06:01
CRDT- 2016/09/17 06:00
PHST- 2016/04/11 00:00 [received]
PHST- 2016/08/24 00:00 [revised]
PHST- 2016/09/02 00:00 [accepted]
PHST- 2016/10/21 06:00 [pubmed]
PHST- 2016/10/21 06:01 [medline]
PHST- 2016/09/17 06:00 [entrez]
AID - S1090-7807(16)30162-8 [pii]
AID - 10.1016/j.jmr.2016.09.001 [doi]
PST - ppublish
SO  - J Magn Reson. 2016 Nov;272:53-59. doi: 10.1016/j.jmr.2016.09.001. Epub 2016 Sep 
      4.