In vivo quantification of regional myocardial blood flow: Validity of the fast-exchange approximation for intravascular T1 contrast agent and long inversion time
✍ Scribed by Marlene Wiart; Sabin Carme; Wilfried Maï; Henrik B.W. Larsson; Bruno Neyran; Emmanuelle Canet-Soulas
- Publisher
- John Wiley and Sons
- Year
- 2006
- Tongue
- English
- Weight
- 329 KB
- Volume
- 56
- Category
- Article
- ISSN
- 0740-3194
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✦ Synopsis
Abstract
In the present study we investigated the effects of water exchange between intra‐ and extravascular compartments on absolute quantification of regional myocardial blood flow (rMBF) using a saturation‐recovery sequence with a rather long inversion time (TI, 176 ms) and a T~1~‐shortening intravascular contrast agent (CMD‐A2‐Gd‐DOTA). Data were acquired in normal and ischemically injured pigs, with radiolabeled microsphere flow measurements used as the gold standard. Five water exchange rates (fast, 6 Hz, 3 Hz, 1 Hz, and no exchange) were tested. The results demonstrate that the fast‐exchange approximation may be appropriate for rMBF quantification using the described experimental setting. Relaxation rate change (Δ__R__~1~) analysis improved the accuracy of the analysis of rMBF compared to the MR signal. In conclusion, the current protocol could provide sufficient accuracy for estimating rMBF assuming fast exchange and a linear relationship between signal and tissue concentration when quantification of precontrast T~1~ is not an option. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.