Bolus dispersion issues related to the quantification of perfusion MRI data

Abstract

Quantification of cerebral blood flow (CBF) using dynamicsusceptibility contrast (DSC) MRI relies on the deconvolution of the arterial input function (AIF). The AIF is commonly measured in a major artery (e.g., the middle cerebral artery), and the estimated function is used as a global AIF for the whole slice. However, the presence of bolus delay and dispersion between the artery and the tissue of interest can introduce significant errors in CBF quantification. While several methods have been introduced to minimize or eliminate the effects of bolus delay, the correction of bolus dispersion is more difficult to address because it requires a model for the vascular bed. This article summarizes how this dispersion effect can be incorporated into the model for CBF quantification, and discusses the magnitude of the errors introduced. Furthermore, alternative methods for correcting or minimizing the effects of bolus dispersion in the quantification of CBF are reviewed.

SCALE-PWI: A Pulse Sequence for Absolute Quantitative Cerebral Perfusion Imaging

“…Dynamic susceptibility contrast (DSC)-MRI methods using an extraneous paramagnetic contrast agent are widely used to produce images of cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time. However, absolute quantification of cerebral perfusion using DSC-MRI methods has been elusive and challenging (Calamante, 2005;Kiselev, 2005;Takasawa et al, 2008;van Osch et al, 2001). Various approaches have been proposed to find the rescaling factor for relative CBF (rCBF) and relative CBV (rCBV) for the quantification of cerebral perfusion.…”

Partial volume effect (PVE) on the arterial input function (AIF) in T1‐weighted perfusion imaging and limitations of the multiplicative rescaling approach

“…However, imaging more caudally may compromise spatial coverage and enhance inflow effects on the AIF. Furthermore, such an approach increases quantification errors due to delay and dispersion of the bolus (11), which on the contrary motivates the use of a local AIF (12). Thus several studies, either based on dynamic susceptibility contrast (DSC) perfusion imaging (6,13,(15)(16)(17)(18)(19) or dynamic contrast-enhanced (DCE) perfusion imaging (14), have compensated the PVE by a multiplicative rescaling.…”

Comparison of Blood Oxygenation Level–Dependent fMRI and Provocative DSC Perfusion MR Imaging for Monitoring Cerebrovascular Reserve in Intracranial Chronic Cerebrovascular Disease

“…[10][11][12] In CVD, the substantial collateral pathways are longer and smaller, so the AIF can be displaced temporally from that of the stenotic cerebral arteries. The multiple temporally displaced arterial inputs from both primary and collateral leptomeningeal vessels may become more exaggerated with vasodilation.…”

“…8,9 The fitted points were limited to the initial baseline, leading edge, and the initial portion of the trailing edge after the peak (Ͻ4 points) to avoid contamination from contrast recirculation. Although other methods may be used, 10 this ␥ variate method avoids bias from the choice of the arterial input function in the setting of CVD. 11,12 The MTT was defined as the first moment of the ␥ variate function fitted to the contrast agent concentration-time-series.…”