Document Detail


A method for rapid in vivo measurement of blood T(1).
MedLine Citation:
PMID:  20669148     Owner:  NLM     Status:  In-Data-Review    
Abstract/OtherAbstract:
We present a technique to measure the longitudinal relaxation time constant of venous blood (T(1b) ) in vivo in a few seconds. The MRI sequence consists of a thick-slab adiabatic inversion, followed by a series of slice-selective excitations and single-shot echo planar imaging readouts. The time intervals between excitations were chosen so that blood in macroscopic vessels is fully refreshed between excitations, making the blood signal follow an unperturbed inversion recovery curve. Static tissue, which experiences the inversion and all excitation pulses, quickly reaches a steady state at a low signal as a result of partial saturation. This allows blood-filled voxels to be discriminated from those containing static tissue, and to be fitted voxel-by-voxel to a simple inversion recovery model. The sequence was tested on a flow phantom with the proposed method, yielding T(1) values consistent to within 3% of those obtained using a conventional inversion recovery sequence with a spin-echo readout. The method was applied to seven adult volunteers and 18 neonates. The blood T(1) of the neonates (1799 ± 206 ms; range, 1393-2035 ms) was found to be more variable than that of adults (1717 ± 39 ms; range, 1662-1779 ms). A linear correlation between the inverse of T(1b) and the haematocrit was established in 12 neonates (R(2)  = 0.90). Copyright © 2010 John Wiley & Sons, Ltd.
Authors:
Marta Varela; Joseph V Hajnal; Esben T Petersen; Xavier Golay; Nazakat Merchant; David J Larkman
Related Documents :
18495028 - Ventricular assist device implant (ab 5000) prototype cannula: in vitro assessment of m...
7811608 - Quantitative magnetic resonance flow imaging.
1545678 - Mr angiography with pulsatile flow.
19532258 - Resonant doppler flow imaging and optical vivisection of retinal blood vessels.
19244588 - Tissue kallikrein deficiency and renovascular hypertension in the mouse.
17195048 - Indomethacin and cerebral autoregulation in severe head injured patients: a transcrania...
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  NMR in biomedicine     Volume:  24     ISSN:  1099-1492     ISO Abbreviation:  NMR Biomed     Publication Date:  2011 Jan 
Date Detail:
Created Date:  2011-01-24     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8915233     Medline TA:  NMR Biomed     Country:  England    
Other Details:
Languages:  eng     Pagination:  80-8     Citation Subset:  IM    
Copyright Information:
Copyright © 2010 John Wiley & Sons, Ltd.
Affiliation:
Imaging Sciences Department, MRC Clinical Sciences Centre, Imperial College London, London, UK.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  The use of MR-detectable reporter molecules and ions to evaluate diffusion in normal and ischemic br...
Next Document:  Non-3D domain swapped crystal structure of truncated zebrafish alphaA crystallin.