Model-free parameters from dynamic contrast-enhanced-MRI: Sensitivity to EES volume fraction and bolus timing
✍ Scribed by John A. Jesberger; Niusha Rafie; Jeffrey L. Duerk; Jeffrey L. Sunshine; Matthew Mendez; Scot C. Remick; Jonathan S. Lewin
- Publisher
- John Wiley and Sons
- Year
- 2006
- Tongue
- English
- Weight
- 167 KB
- Volume
- 24
- Category
- Article
- ISSN
- 1053-1807
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✦ Synopsis
Abstract
Purpose
To quantify the unknown relative sensitivities of semiquantitative measures from dynamic contrast‐enhanced (DCE) MRI to variations in the volume fraction V~e~ of the extravascular extracellular space (EES), and the duration of the contrast injection.
Materials and Methods
Tissue‐uptake curves were simulated across various values of F, PS, V~e~, and bolus timings, with and without additive noise and at different image reacquisition rates. From each, the peak of the first derivative (G~peak~), the total uptake after the rapid first phase (CE), and the IAUC were calculated and plotted against F for each experimental condition. Relationships between each measure and the corresponding quantitative measure K^trans^ were also examined, particularly for linearity.
Results
The highest sensitivity to flow was achieved for shorter bolus timings for G~peak~, CE, and IAUC. G~peak~ and IAUC were most linearly related to K^trans^. The sensitivity to V~e~ was lowest for G~peak~, followed by IAUC and CE. Long sampling intervals resulted in severe underestimation of G~peak~, while IAUC was unaffected provided that the limits of integration were properly applied. G~peak~ could not be properly calculated in the presence of noise without a prior smoothing of the acquired curves, while IAUC was again unaffected by noise.
Conclusion
G~peak~ and IAUC are both useful model‐free analogs of blood flow (i.e., K^trans^) for pre‐ and posttreatment comparisons. G~peak~ may be the better choice in cases where larger changes in V~e~ are likely, but only if sufficient noise reduction and fast image sampling are applied. If V~e~ is expected to remain stable, IAUC is superior to G~peak~ by virtue of its stability in the face of noise and more reliable estimation over a wider range of sampling rates. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.