Temporal sampling requirements for reference region modeling of DCE-MRI data in human breast cancer.
OBJECTIVE
To assess the temporal sampling requirements needed for quantitative analysis of dynamic contrast-enhanced MRI (DCE-MRI) data with a reference region (RR) model in human breast cancer.


METHODS
Simulations were used to study errors in pharmacokinetic parameters (K(trans) and v(e)) estimated by the RR model using six DCE-MRI acquisitions over a range of pharmacokinetic parameter values, arterial input functions, and temporal samplings. DCE-MRI data were acquired on 12 breast cancer patients and parameters were estimated using the native resolution data (16.4 seconds) and compared to downsampled 32.8-second and 65.6-second data.


RESULTS
Simulations show that, in the majority of parameter combinations, the RR model results in an error less than 20% in the extracted parameters with temporal sampling as poor as 35.6 seconds. The experimental results show a high correlation between K(trans) and v(e) estimates from data acquired at 16.4-second temporal resolution compared to the downsampled 32.8-second data: the slope of the regression line was 1.025 (95% confidence interval [CI]: 1.021, 1.029), Pearson's correlation r = 0.943 (95% CI: 0.940, 0.945) for K(trans), and 1.023 (95% CI: 1.021. 1.025), r = 0.979 (95% CI: 0.978, 0.980) for v(e). For the 64-second temporal resolution data the results were: 0.890 (95% CI: 0.894, 0.905), r = 0.8645, (95% CI: 0.858, 0.871) for K(trans), and 1.041 (95% CI: 1.039, 1.043), r = 0.970 (95% CI: 0.968, 0.971) for v(e).


CONCLUSIONS
RR analysis allows for a significant reduction in temporal sampling requirements and this lends itself to analyze DCE-MRI data acquired in practical situations.
Planey
Catherine R
CR
Department of Biomedical Engineering, Yale University, New Haven, Connecticut, USA.
Welch
E Brian
EB
Xu
Lei
L
Chakravarthy
A Bapsi
AB
Gatenby
J Christopher
JC
Freehardt
Darla
D
Mayer
Ingrid
I
Meszeoly
Ingrid
I
Kelley
Mark
M
Means-Powell
Julie
J
Gore
John C
JC
Yankeelov
Thomas E
TE
D001940:Breast / Q000473:pathology; D001943:Breast Neoplasms / Q000473:pathology*; D003198:Computer Simulation / Q000706:statistics & numerical data; D003287:Contrast Media / Q000493:pharmacokinetics; D005260:Female; D019786:Gadolinium DTPA / Q000493:pharmacokinetics; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008954:Models, Biological; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013997:Time Factors
D003287:Contrast Media; D019786:Gadolinium DTPA