Premium
Continuous saturation EPI with diffusion weighting at 3.0 T
Author(s) -
Francis Susan T.,
Gowland Penny A.,
Bowtell Richard W.
Publication year - 1999
Publication title -
nmr in biomedicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.278
H-Index - 114
eISSN - 1099-1492
pISSN - 0952-3480
DOI - 10.1002/(sici)1099-1492(199911)12:7<440::aid-nbm592>3.0.co;2-d
Subject(s) - saturation (graph theory) , perfusion , weighting , nuclear magnetic resonance , chemistry , nuclear medicine , biomedical engineering , mathematics , physics , medicine , cardiology , combinatorics , acoustics
This paper presents a steady‐state method of arterial spin labelling using continuous saturation in conjunction with echo‐planar imaging (EPI), which has been implemented at 3 T. The continuous saturation technique has the advantage of having high sensitivity compared to transient labelling techniques, when long repetition times are used. It is also easy to implement and requires minimal data to be acquired for quantitation. Like other arterial spin labelling techniques, continuous saturation is potentially prone to overestimation of perfusion rates due to the effect of tagged blood in vessels within the image slice. Using a simple model of the vasculature, the degree of diffusion weighting required to suppress the arterial signal has been determined, with the results indicating that a value of 2 s/mm 2 is adequate. Histogram analysis of the experimental data has been used to evaluate the effect of diffusion weighting. Using a b ‐value of 2 s/mm 2 , the mean perfusion‐related signal change in grey matter on continuous saturation was found to be 1.5 ± 0.2%, yielding a mean perfusion rate of 87 ± 9 ml/100 g/min. Brain activation studies using the diffusion weighted continuous saturation technique gave a mean increase in perfusion of 36 ± 12% in activated motor cortex. Copyright © 1999 John Wiley & Sons, Ltd.