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Titolo:
On the use of the FLAIR technique to improve the correction of eddy current induced artefacts in MR diffusion tensor imaging
Autore:
Bastin, ME;
Indirizzi:
Univ Edinburgh, Western Gen Hosp, Dept Med Phys & Med Engn, Edinburgh EH4 2XU, Midlothian, Scotland Univ Edinburgh Edinburgh Midlothian Scotland EH42XU Midlothian, Scotland
Titolo Testata:
MAGNETIC RESONANCE IMAGING
fascicolo: 7, volume: 19, anno: 2001,
pagine: 937 - 950
SICI:
0730-725X(200109)19:7<937:OTUOTF>2.0.ZU;2-E
Fonte:
ISI
Lingua:
ENG
Soggetto:
ECHO-PLANAR IMAGES; CURRENT-INDUCED ARTIFACTS; HUMAN BRAIN; MAGNETIC-RESONANCE; SPIN-ECHO; GRADIENT-ECHO; ANISOTROPY;
Keywords:
diffusion; echo-planar; distortion; warping; FLAIR;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Clinical Medicine
Citazioni:
39
Recensione:
Indirizzi per estratti:
Indirizzo: Bastin, ME Univ Edinburgh, Western Gen Hosp, Dept Med Phys & Med Engn, Crewe Rd, Edinburgh EH4 2XU, Midlothian, Scotland Univ Edinburgh Crewe Rd Edinburgh Midlothian Scotland EH4 2XU d
Citazione:
M.E. Bastin, "On the use of the FLAIR technique to improve the correction of eddy current induced artefacts in MR diffusion tensor imaging", MAGN RES IM, 19(7), 2001, pp. 937-950

Abstract

Eddy current induced geometric distortions can only be accurately corrected in brain diffusion-weighted echo-planar (DW-EP) images for b-values less than approximately 300 s mm(-2) using the iterative cross-correlation (ICC)algorithm. This is due to the difference in signal intensity of the cerebrospinal fluid (CSF) compartment in the diffusion-weighted and baseline T-2-weighted echo-planar (T2W-EP) images. At larger values of b, image misalignment artefacts can, however, be removed by directly correlating CSF-suppressed T2W-EP images with non-CSF-suppressed and CSF-suppressed DW-EP images. Separate phantom experiments can also be performed to provide eddy current calibration data. Here the ability of these methods to remove eddy current induced artefacts from DW-EP images collected in volunteer diffusion tensorimaging (DTI) experiments is investigated. Monte Carlo simulations show that in order for the ICC algorithm to produce accurate estimates of the eddycurrent induced distortions at b-values greater than 1000 s mm(-2), the degree of CSF suppression should be greater than approximately 80%. This condition is typically met for FLAIR inversion times between 0.5 and 0.8 of thespin-lattice relaxation time of CSF. In volunteer studies the most complete image realignment was provided by direct correlation of CSF-suppressed T2W-EP and DW-EP images acquired in the FLAIR DTI experiment. These results indicate that although calibration data obtained from brain or phantom images can significantly reduce eddy current induced distortions, the optimum image realignment achievable using post-processing methods is likely to be that obtained by direct image warping techniques. (C) 2001 Elsevier Science Inc. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 20/01/20 alle ore 23:04:46