MR technology: effect of even-echo rephasing on calculated T2 values and T2 images

Details

Serval ID
serval:BIB_8F10F0D6627E
Type
Article: article from journal or magazin.
Collection
Publications
Title
MR technology: effect of even-echo rephasing on calculated T2 values and T2 images
Journal
Radiology
Author(s)
Kucharczyk  W., Brant-Zawadzki  M., Lemme-Plaghos  L., Uske  A., Kjos  B., Feinberg  D. A., Norman  D.
ISSN
0033-8419 (Print)
Publication state
Published
Issued date
10/1985
Volume
157
Number
1
Pages
95-101
Notes
Kucharczyk, W
Brant-Zawadzki, M
Lemme-Plaghos, L
Uske, A
Kjos, B
Feinberg, D A
Norman, D
United states
Radiology
Radiology. 1985 Oct;157(1):95-101. --- Old month value: Oct --- Old uritopublisher value: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=4034984
Abstract
In multiple spin-echo image sequences of blood flow, the "even-echo" phenomenon produces an absolute increase in signal magnitude from first- to second-echo images of normal vessels harboring slow flow. Distinguishing this from the apparent relatively high signal intensity seen on second-echo images in pathologic foci of stationary tissue is important to the diagnostician. Selected case material containing two tissue types was reviewed retrospectively: tissues known to harbor slow flow, such as normal veins and venous sinuses and vascular malformations, and tissues that have long transverse (T2) relaxation times and appear as intense structures on second-echo images, such as neoplasms, infarcts, and regions of demyelination. Calculations of T2 parameters were made by computer for defined regions of interest. T2 images were also generated. Visual inspection of the acquired images did not reliably distinguish increased intensity due to even-echo rephasing from the relative changes between adjacent tissues seen on second-echo images. More definitive differentiation of the even-echo phenomenon was provided by calculated values of T2 and computer-synthesized T2 images representing acquired intensity data of two-echo sequences. The synthesized images were especially useful when stationary tissue with lengthened T2 values was adjacent to or in proximity to vessels or vascular lesions. A five spin-echo image sequence was valuable for separating slow flow from stationary tissue by a technique of synthesizing T2-difference images using three consecutive echoes.
Keywords
Brain Diseases/*diagnosis Brain Neoplasms/diagnosis Cerebrovascular Circulation Cerebrovascular Disorders/diagnosis Computers Humans Intracranial Arteriovenous Malformations/diagnosis Magnetic Resonance Spectroscopy/diagnostic use/*methods
Pubmed
Web of science
Create date
25/07/2008 10:54
Last modification date
20/08/2019 14:52
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