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Precision in measurements of perfusion and microvascular permeability with T 1 ‐weighted dynamic contrast‐enhanced MRI
Author(s) -
Kershaw Lucy E.,
Buckley David L.
Publication year - 2006
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.21040
Subject(s) - homogeneity (statistics) , dynamic contrast enhanced mri , contrast (vision) , accuracy and precision , perfusion , blood flow , mathematics , coefficient of variation , nuclear medicine , statistics , biological system , magnetic resonance imaging , computer science , biomedical engineering , medicine , radiology , artificial intelligence , biology
Dynamic contrast‐enhanced MRI is used to estimate microvascular parameters by tracer kinetics analysis. The time for the contrast agent to travel from the artery to the tissue of interest (bolus arrival time (BAT)) is an important parameter that must be measured in such studies because inaccurate estimates or neglect of BAT contribute to inaccuracy in model fitting. Furthermore, although the precision with which these parameters are estimated is very important, it is rarely reported. To address these issues, two investigations were undertaken. First, simulated data were used to validate an independent method for estimation of BAT. Second, the adiabatic approximation to the tissue homogeneity model was fitted to experimental data acquired in prostate and muscle tissue of 22 patients with prostate cancer. A bootstrap error analysis was performed to estimate the precision of parameter estimates. The independent method of estimating BAT was found to be more accurate and precise than a model‐fitting approach. Estimated precisions for parameters measured in the prostate gland were 14% for extraction fraction (median coefficient of variation), 19% for blood flow, 28% for permeability‐surface area product, 35% for volume of the extravascular‐extracellular space, and 36% for blood volume. Techniques to further reduce uncertainty are discussed. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.