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Titolo:
High b-value diffusion-weighted MRI of normal brain
Autore:
Burdette, JH; Durden, DD; Elster, AD; Yen, YF;
Indirizzi:
Wake Forest Univ, Bowman Gray Sch Med, Dept Radiol, Winston Salem, NC 27157 USA Wake Forest Univ Winston Salem NC USA 27157 , Winston Salem, NC 27157 USA Wake Forest Univ, Bowman Gray Sch Med, Dept Med Engn, Winston Salem, NC 27157 USA Wake Forest Univ Winston Salem NC USA 27157 , Winston Salem, NC 27157 USA
Titolo Testata:
JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY
fascicolo: 4, volume: 25, anno: 2001,
pagine: 515 - 519
SICI:
0363-8715(200107/08)25:4<515:HBDMON>2.0.ZU;2-7
Fonte:
ISI
Lingua:
ENG
Soggetto:
ACUTE CEREBRAL-ISCHEMIA; ACUTE HUMAN STROKE; SPIN-DENSITY; CLINICAL-APPLICATIONS; T2-WEIGHTED MRI; COEFFICIENT ADC; TIME-COURSE; INFARCTION; REPRODUCIBILITY; RELAXATION;
Keywords:
magnetic resonance imaging; magnetic resonance imaging, techniques; brain;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Clinical Medicine
Life Sciences
Citazioni:
27
Recensione:
Indirizzi per estratti:
Indirizzo: Burdette, JH Wake Forest Univ, Bowman Gray Sch Med, Dept Radiol, Bowman Gray Campus,MedCtr Blvd, Winston Salem, NC 27157 USA Wake Forest Univ Bowman Gray Campus,Med Ctr Blvd Winston Salem NC USA 27157
Citazione:
J.H. Burdette et al., "High b-value diffusion-weighted MRI of normal brain", J COMPUT AS, 25(4), 2001, pp. 515-519

Abstract

Purpose: As MR scanner hardware has improved, allowing for increased gradient strengths, we are able to generate higher b values for diffusion-weighted (DW) imaging. Our purpose was to evaluate the appearance of the normal brain on DW MR images as the diffusion gradient strength ("b value") is increased from 1,000 to 3,000 s/mm(2)Method: Three sets of echo planar images were acquired at 1.5 T in 25 normal subjects (mean age 61 years) using progressively increasing strengths ofa diffusion-sensitizing gradient (corresponding to b values of 0, 1,000, and 3,000 s/mm(2)). All other imaging parameters remained constant. Qualitative assessments of trace images were performed by two neuroradiologists, supplemented by quantitative measures of MR signal and noise in eight different anatomic regions. Results: As gradient strength increased from b = 1,000 to 3,000, both grayand white matter structures diminished in signal as expected based on their relative diffusion coefficients [calculated average apparent diffusion coefficient (ADC) values: gray matter = 8.5 x 10(-4) mm(2)/s, white matter = 7.5 x 10(-4) mm(2)/s]. The signal-to-noise ratios for the b = 1,000 images were approximately 2.2 times higher than for the b = 3,000 images (p < 0.0001). As the strength of the diffusion-sensitizing gradient increased, whitematter became progressively hyperintense to gray matter. Relative to the thalamus, for example, the average MR signal intensity of white matter structures increased by an average of 27.5%, with the densely packed white matter tracts (e.g., middle cerebellar peduncle, tegmentum, and internal capsule) increasing the most. Conclusion: Brain DW images obtained at b = 3,000 appear significantly different from those obtained at b = 1,000, reflecting expected loss of signalfrom all areas of brain in proportion to their ADC values. Consequently, when all other imaging parameters are held constant, b = 3,000 DW images appear significantly noisier than b = 1,000 images, and white matter tracts are significantly more hyperintense than gray matter structures.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 29/03/20 alle ore 08:56:09