Mechanisms of MR signal alteration by acute intracerebral blood: old concepts and new theories.

Mechanisms of MR signal alteration by acute intracerebral blood: old concepts and new theories. Research Abstract Details 

Research Abstract Table of Contents

Jump to the:

Mechanisms of MR signal alteration by acute intracerebral blood: old concepts and new theories. Abstract Text:

L A Hayman,K H Taber,J J Ford,R N Bryan,

We reviewed the current literature and theories pertaining to the appearance of hemorrhage on MR images. New theories were formulated to explain the etiology of spin-echo (SE) and gradient-echo contrast on clinical MR images of hematomas at low and intermediate field strengths. It is our hope that these theories will prompt further experiments to prove or disprove their validity. The discussion of SE contrast focuses on the powerful MR effects mediated by changes in protein concentration. These changes are postulated to occur as a result of (1) clot matrix formation; (2) settling of RBCs, which increases the number of RBCs per unit volume and the total protein concentration; and (3) alterations in intracellular protein concentration caused by changes in RBC hydration. The contribution of acid methemoglobin to image contrast via the proton electron dipole-dipole mechanism is also included. The discussion of gradient-echo contrast focuses on the inhomogeneity that may be present within voxels that contain a blood clot. This inhomogeneity results when the voxel contains regions with different magnetic susceptibilities (i.e., clumped RBCs and serum). Two temporally arranged schemata for T2-weighted and T1-weighted SE scans are presented that illustrate how these factors might interact to explain the diverse appearance of hematomas on clinical SE images. The signal intensity on T2-weighted SE scans appears to be dependent primarily on the state of hydration of the RBC. This factor and the presence or absence of methemoglobin appear to be the major factors that govern contrast on T1-weighted SE images.

Mechanisms of MR signal alteration by acute intracerebral blood: old concepts and new theories. Publishing Authors By Initials

LA Hayman,KH Taber,JJ Ford,RN Bryan,

For similar proteins research abstracts see: proteins research

PUBMED ID PMID:

MEDLINE DATE:

Mechanisms of MR signal alteration by acute intracerebral blood: old concepts and new theories. Journal Published:

PUBLICATION TYPE: Review

Journal: AJNR. American journal of neuroradiology

VOLUME: 12

Page Numbers: 899-907

Journal Abbreviation:

ISSN: 0195-6108

DAY: 14

MONTH: 02

YEAR: 2008

Mechanisms of MR signal alteration by acute intracerebral blood: old concepts and new theories. Information

Number of References: 50

LANGUAGE: eng

NlmUniqueID: 8003708

Mechanisms of MR signal alteration by acute intracerebral blood: old concepts and new theories. Keywords Mesh Terms:

KEYWORDS: Proteins

MESH TERMS: metabolism

Chemical & Substance for Abstract: Mechanisms of MR signal alteration by acute intracerebral blood: old concepts and new theories. Information

Substance Name: Proteins

Registry Number: 0

Grant and Affiliation Information for Mechanisms of MR signal alteration by acute intracerebral blood: old concepts and new theories.

AFFILIATION: Department of Radiology, Baylor College of Medicine, Houston, TX 77030.

Country: UNITED STATES

AGENCY:

GRANT:

ACRONYM:

MEDLINETA: AJNR Am J Neuroradiol

REFSOURCE:

DATABASENAME:

ACCESSION NUMBER:

Number Hits: 0

Mechanisms of MR signal alteration by acute intracerebral blood: old concepts and new theories Related Publications

• A molecular phylogeny of Anopheles annulipes (Diptera: Culicidae) sensu lato: the most species-rich anopheline complex.
• A role for dietary saccharide intake in cognitive performance.
• Antibodies from women immunized with Gardasil cross-neutralize HPV 45 pseudovirions.
• Carbamates in the chemotherapy of leukemia; the relationship between chemical structure and anti-leukemic action of a series of urethan derivatives.
• Consistent condom use among juvenile detainees: the role of individual differences, social bonding, and health beliefs.
• Cost-effectiveness analysis and formulary decision making in England: findings from research.
• Defining a binding pocket for sulfonylureas in ATP-sensitive potassium channels.
• Distribution of NRPS gene families within the Neotyphodium/Epichloë complex.
• Feminist therapy with people who self-inflict violence.
• Hydrogen-deuterium exchange in free and prodomain-complexed subtilisin.
• Image registration based on boundary mapping.
• Imaging of the Mind: Yesterday's Triumphs and Tomorrow's Challenges.
• LABORATORY: PRESERVATION OF MILK SAMPLES WITH BRILLIANT GREEN FOR STREPTOCOCCUS AND ABORTUS EXAMINATION.
• Luminescence from the trans-dioxotechnetium(V) chromophore.
• Mechanism of the kinetically-controlled folding reaction of subtilisin.
• Motivational enhancement therapy for high-risk adolescent smokers.
• Penicillin in the Treatment of Infectious Bovine Mastitis.
• Polycystic kidney disease.
• QTL mapping of yield, agronomic and quality traits in tetraploid potato (Solanum tuberosum subsp. tuberosum).
• Re: Neuropsychology of BPI and BPII.
• Signs and portents in medicine.
• Studies on bovine mastitis; the incidence of streptococci in milk in relation to the number of lactations.
• Studies on the hazard involved in use of C14; retention of carbon from labeled sodium bicarbonate.
• Systemic inflammatory response after endoluminal stenting of the descending thoracic aorta.
• Telomerase recognizes G-quadruplex and linear DNA as distinct substrates.
• The design and characterization of two proteins with 88% sequence identity but different structure and function.
• The pathology of the toxemias of late pregnancy.
• The seven basic virtues in medicine: VII. Love.
• The technic of saddle block analgesia in obstetrics.
• Using a deformable surface model to obtain a shape representation of the cortex.