Fig. 3.

Images and maps from a high-grade tumor in a 2-year-old boy with a glioblastoma (classified as grade IV) scanned at center 4 on a 3-T Achieva (Philips, Best, the Netherlands). a Pre-contrast axial T2-weighted MR image (turbo spin-echo sequence, repetition time/echo time [TR/TE] = 6,272/85 ms, number of signals averaged [NSA] = 1, acquired with 4-mm slice thickness and 10% gap, reformatted to the dynamic susceptibility-contrast acquisition of 3.5-mm slice thickness, no gap and 1.8×1.8-mm in-plane resolution), on which the tumor region of interest was defined. b Post-contrast axial T1-weighted MR image (spin-echo sequence, TR/TE=1,179/14 ms, NSA=1, acquired with 4-mm slice thickness, 10% gap, reformatted as in (a) shows high signal in the tumor. c–e Uncorrected (c) and leakage-corrected (d) relative cerebral volume (rCBV) maps and K₂ map (e) acquired in the axial plane. Dynamic susceptibility-contrast data were acquired with an sPRESTO sequence (TR/TE=15.9/23.9 ms, flip angle 7^o, with 30 slices at 1.8×1.8×3.5-mm resolution). The uncorrected rCBV map shows high values within the tumor. After correction, rCBV is shown to decrease. The K₂ map shows negative values within the tumor compared to surrounding normal tissue. Normalized uncorrected rCBV was high both before and after leakage correction (3.66 vs. 2.68) and K₂ was −0.013. sPRESTO sensitivity-encoded Philips principles of echo-shifting with a train of observations