title: Assessment of a simplified spin and gradient echo (sSAGE) approach for human brain tumor perfusion imaging.
abstract: The goal of this study was to validate a simplified spin- and gradient-echo (sSAGE) approach to obtain T1-corrected dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) data in a clinical brain tumor population. A five-echo SAGE sequence was used to acquire DSC-MRI data (n=8 patients, 3 primary glioma, and 5 brain metastases). The ΔR2⁎and ΔR2time series obtained from a nonlinear fit of all echoes (SAGE) were compared to ΔR2⁎and ΔR2time series obtained analytically (sSAGE) using three echoes (two GEs and one SE). Through the use of multiple echoes, both methods removed T1leakage effects from the ΔR2⁎and ΔR2time series, and the sSAGE ΔR2⁎and ΔR2time series were highly correlated with those from SAGE, with average correlations of 0.9. The resulting hemodynamic parameters included GE and SE cerebral blood volume (CBV), cerebral blood flow (CBF), mean vessel diameter (mVD), volume transfer constant (Ktrans), and volume fraction of the extravascular extracellular space (ve). For each metric, there was good correlation (>0.86) between sSAGE and SAGE, with no significant differences. The sSAGE method provides T1-corrected GE and SE DSC-MRI parameters in an efficient and clinically feasible manner.
authors.affiliation: Institute of Imaging Science, Vanderbilt University, 1161 21st Ave. S, Nashville, TN 37232, USA.
authors.forename: Ashley M
authors.initials: AM
authors.lastname: Stokes
authors.affiliation: Institute of Imaging Science, Vanderbilt University, 1161 21st Ave. S, Nashville, TN 37232, USA.
authors.forename: Jack T
authors.initials: JT
authors.lastname: Skinner
authors.affiliation: Institute of Imaging Science, Vanderbilt University, 1161 21st Ave. S, Nashville, TN 37232, USA.
authors.forename: Thomas
authors.initials: T
authors.lastname: Yankeelov
authors.affiliation: Institute of Imaging Science, Vanderbilt University, 1161 21st Ave. S, Nashville, TN 37232, USA. Electronic address: Christopher.Quarles@DignityHealth.org.
authors.forename: C Chad
authors.initials: CC
authors.lastname: Quarles
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000098:blood supply / Q000000981:diagnostic imaging; D001932:Brain Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000473:pathology; D002560:Cerebrovascular Circulation; D003287:Contrast Media; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results
chemical_list: D003287:Contrast Media
keywords: Contrast agent leakage; Dynamic susceptibility-contrast MRI; Perfusion imaging; Permeability; Spin-echo and gradient-echo EPI