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PT  - JOURNAL ARTICLE
AU  - Leu, K.
AU  - Boxerman, J.L.
AU  - Cloughesy, T.F.
AU  - Lai, A.
AU  - Nghiemphu, P.L.
AU  - Liau, L.M.
AU  - Pope, W.B.
AU  - Ellingson, B.M.
TI  - Improved Leakage Correction for Single-Echo Dynamic Susceptibility Contrast Perfusion MRI Estimates of Relative Cerebral Blood Volume in High-Grade Gliomas by Accounting for Bidirectional Contrast Agent Exchange
AID  - 10.3174/ajnr.A4759
DP  - 2016 Aug 01
TA  - American Journal of Neuroradiology
PG  - 1440--1446
VI  - 37
IP  - 8
4099  - http://www.ajnr.org/content/37/8/1440.short
4100  - http://www.ajnr.org/content/37/8/1440.full
SO  - Am. J. Neuroradiol.2016 Aug 01; 37
AB  - BACKGROUND AND PURPOSE: Contrast agent extravasation through a disrupted blood-brain barrier potentiates inaccurate DSC MR imaging estimation of relative CBV. We explored whether incorporation of an interstitial washout rate in a leakage-correction model for single-echo, gradient-echo DSC MR imaging improves relative CBV estimates in high-grade gliomas.MATERIALS AND METHODS: We modified the traditional model-based postprocessing leakage-correction algorithm, assuming unidirectional contrast agent extravasation (Boxerman-Weisskoff model) to account for bidirectional contrast agent exchange between intra- and extravascular spaces (bidirectional model). For both models, we compared the goodness of fit with the parent leakage-contaminated relaxation rate curves by using the Akaike Information Criterion and the difference between modeled interstitial relaxation rate curves and dynamic contrast-enhanced MR imaging by using Euclidean distance in 21 patients with glioblastoma multiforme.RESULTS: The bidirectional model had improved Akaike Information Criterion versus the bidirectional model in &amp;gt;50% of enhancing tumor voxels in all 21 glioblastoma multiformes (77% ± 9%; P &amp;lt; .0001) and had reduced the Euclidean distance in &amp;gt;50% of enhancing tumor voxels for 17/21 glioblastoma multiformes (62% ± 17%; P = .0041). The bidirectional model and dynamic contrast-enhanced-derived kep demonstrated a strong correlation (r = 0.74 ± 0.13). On average, enhancing tumor relative CBV for the Boxerman-Weisskoff model exceeded that for the bidirectional model by 16.6% ± 14.0%.CONCLUSIONS: Inclusion of the bidirectional exchange in leakage-correction models for single-echo DSC MR imaging improves the model fit to leakage-contaminated DSC MR imaging data and significantly improves the estimation of relative CBV in high-grade gliomas.AICAkaike Information Criterionbidir modelbidirectional modelBW modelBoxerman-Weisskoff modelΔR2*transverse relaxation rateDCEdynamic contrast-enhancedGBMglioblastoma multiformekeptransfer constant from the extracellular extravascular space back to the blood plasmaKtranscontrast transfer coefficientrCBVrelative cerebral blood volume