Dynamic susceptibility MRI with a pre-bolus administration design for improved absolute quantification of perfusion

Purpose Reproducible absolute quantification of cerebral blood volume (CBV) and cerebral blood flow (CBF) by dynamic susceptibility contrast MRI (DSC-MRI) is difficult to achieve, for example, due to partial-volume effects (PVEs). Rescaling of the arterial input function (AIF) using a corrected venous output function (VOF) in DSC-MRI has been shown to improve the correlation between CBF estimates obtained by DSC-MRI and Xe-133 SPECT [1]. However, the VOF obtained from the superior sagittal sinus is often distorted at peak concentration by signal displacement caused by the low bandwidth of the single-shot GRE-EPI [2] and by signal saturation at the high TE required to obtain adequate signal reduction in tissue [3]. The purpose of this study was to correct for arterial PVEs by rescaling the AIF using a VOF obtained by injecting a fraction of the contrast-agent dose as a pre-bolus [4]. During the pre-bolus passage, a segmented EPI sequence in single-slice mode was used to register the VOF in the superior sagittal sinus. Using segmented EPI, a higher bandwidth can be used to avoid large-vessel geometric distortion during the bolus passage. Furthermore, since the brain tissue is not the target of this part of the examination, a short TE can be used during the pre-bolus passage to avoid large-vessel signal saturation.