Water content and water structure in CT and MR signal changes: Possible influence in detection of early stroke

Evan C Unger, J. Littlefield, M. Gado

Research output: Contribution to journalArticle

89 Citations (Scopus)

Abstract

Recent work by the authors and others has shown that MR imaging is more sensitive than CT in the detection of acute stroke. To separate the effects of water content and water structure on MR signal intensity, we undertook two sets of experiments that used simple model systems: gelatin gels with increasing water content and hardened hens' eggs. CT and MR were performed on both systems. On CT there was a direct linear relationship between CT attenuation (Hounsfield units) and the specific gravity of the gelatin gels, and an inverse relationship with water content. There was only a minimal change in the specific gravity of egg samples with hardening and, as expected on CT, no change in linear attenuation accompanying hardening. On MR there was a linear relationship between water content in gelatin gels and spin-lattice (T1) relaxation time (r = .92, p < .01) and spin-spin (T2) relaxation time (r = .91, p < .05). However, these changes were insufficient to explain the changes of signal intensity that occur in the brain with infarction. The simple cellular system with hens' eggs demonstrated that shortening of T1 and T2 accompanied egg hardening with minimal change in water content; the shift of water from bulk water to a bound or structured form was probably the basis of this phenomenon. We found that water structure and not merely water content is a significant mechanism underlying relaxation time changes and signal intensity changes in acute stroke.

Original languageEnglish (US)
Pages (from-to)687-691
Number of pages5
JournalAmerican Journal of Neuroradiology
Volume9
Issue number4
StatePublished - 1988
Externally publishedYes

Fingerprint

Stroke
Water
Gelatin
Specific Gravity
Gels
Eggs
Ovum
Brain Infarction

ASJC Scopus subject areas

  • Clinical Neurology
  • Radiology Nuclear Medicine and imaging
  • Radiological and Ultrasound Technology

Cite this

Water content and water structure in CT and MR signal changes : Possible influence in detection of early stroke. / Unger, Evan C; Littlefield, J.; Gado, M.

In: American Journal of Neuroradiology, Vol. 9, No. 4, 1988, p. 687-691.

Research output: Contribution to journalArticle

@article{e07b88c74aad41c882ec3dbc62e9293f,
title = "Water content and water structure in CT and MR signal changes: Possible influence in detection of early stroke",
abstract = "Recent work by the authors and others has shown that MR imaging is more sensitive than CT in the detection of acute stroke. To separate the effects of water content and water structure on MR signal intensity, we undertook two sets of experiments that used simple model systems: gelatin gels with increasing water content and hardened hens' eggs. CT and MR were performed on both systems. On CT there was a direct linear relationship between CT attenuation (Hounsfield units) and the specific gravity of the gelatin gels, and an inverse relationship with water content. There was only a minimal change in the specific gravity of egg samples with hardening and, as expected on CT, no change in linear attenuation accompanying hardening. On MR there was a linear relationship between water content in gelatin gels and spin-lattice (T1) relaxation time (r = .92, p < .01) and spin-spin (T2) relaxation time (r = .91, p < .05). However, these changes were insufficient to explain the changes of signal intensity that occur in the brain with infarction. The simple cellular system with hens' eggs demonstrated that shortening of T1 and T2 accompanied egg hardening with minimal change in water content; the shift of water from bulk water to a bound or structured form was probably the basis of this phenomenon. We found that water structure and not merely water content is a significant mechanism underlying relaxation time changes and signal intensity changes in acute stroke.",
author = "Unger, {Evan C} and J. Littlefield and M. Gado",
year = "1988",
language = "English (US)",
volume = "9",
pages = "687--691",
journal = "American Journal of Neuroradiology",
issn = "0195-6108",
publisher = "American Society of Neuroradiology",
number = "4",

}

TY - JOUR

T1 - Water content and water structure in CT and MR signal changes

T2 - Possible influence in detection of early stroke

AU - Unger, Evan C

AU - Littlefield, J.

AU - Gado, M.

PY - 1988

Y1 - 1988

N2 - Recent work by the authors and others has shown that MR imaging is more sensitive than CT in the detection of acute stroke. To separate the effects of water content and water structure on MR signal intensity, we undertook two sets of experiments that used simple model systems: gelatin gels with increasing water content and hardened hens' eggs. CT and MR were performed on both systems. On CT there was a direct linear relationship between CT attenuation (Hounsfield units) and the specific gravity of the gelatin gels, and an inverse relationship with water content. There was only a minimal change in the specific gravity of egg samples with hardening and, as expected on CT, no change in linear attenuation accompanying hardening. On MR there was a linear relationship between water content in gelatin gels and spin-lattice (T1) relaxation time (r = .92, p < .01) and spin-spin (T2) relaxation time (r = .91, p < .05). However, these changes were insufficient to explain the changes of signal intensity that occur in the brain with infarction. The simple cellular system with hens' eggs demonstrated that shortening of T1 and T2 accompanied egg hardening with minimal change in water content; the shift of water from bulk water to a bound or structured form was probably the basis of this phenomenon. We found that water structure and not merely water content is a significant mechanism underlying relaxation time changes and signal intensity changes in acute stroke.

AB - Recent work by the authors and others has shown that MR imaging is more sensitive than CT in the detection of acute stroke. To separate the effects of water content and water structure on MR signal intensity, we undertook two sets of experiments that used simple model systems: gelatin gels with increasing water content and hardened hens' eggs. CT and MR were performed on both systems. On CT there was a direct linear relationship between CT attenuation (Hounsfield units) and the specific gravity of the gelatin gels, and an inverse relationship with water content. There was only a minimal change in the specific gravity of egg samples with hardening and, as expected on CT, no change in linear attenuation accompanying hardening. On MR there was a linear relationship between water content in gelatin gels and spin-lattice (T1) relaxation time (r = .92, p < .01) and spin-spin (T2) relaxation time (r = .91, p < .05). However, these changes were insufficient to explain the changes of signal intensity that occur in the brain with infarction. The simple cellular system with hens' eggs demonstrated that shortening of T1 and T2 accompanied egg hardening with minimal change in water content; the shift of water from bulk water to a bound or structured form was probably the basis of this phenomenon. We found that water structure and not merely water content is a significant mechanism underlying relaxation time changes and signal intensity changes in acute stroke.

UR - http://www.scopus.com/inward/record.url?scp=0023784990&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0023784990&partnerID=8YFLogxK

M3 - Article

C2 - 3135715

AN - SCOPUS:0023784990

VL - 9

SP - 687

EP - 691

JO - American Journal of Neuroradiology

JF - American Journal of Neuroradiology

SN - 0195-6108

IS - 4

ER -