Multi-delay multi-parametric arterial spin-labeled perfusion MRI in acute ischemic stroke — Comparison with dynamic susceptibility contrast enhanced perfusion imaging

Abstract

The purpose of the present study was to present a multi-delay multi-parametric pseudo-continuous arterial spin labeling (pCASL) protocol with background suppressed 3D GRASE (gradient and spin echo) readout for perfusion imaging in acute ischemic stroke. PCASL data at 4 post-labeling delay times (PLD = 1.5, 2, 2.5, 3 s) were acquired within 4.5 min in 24 patients (mean age 79.7 ± 11.4 years; 11 men) with acute middle cerebral artery (MCA) stroke who also underwent dynamic susceptibility contrast (DSC) enhanced perfusion imaging. Arterial transit times (ATT) were estimated through the calculation of weighted delays across the 4 PLDs, which were included in the calculation of cerebral blood flow (CBF) and arterial cerebral blood volume (CBV). Mean perfusion parameters derived using pCASL and DSC were measured within MCA territories and infarct regions identified on diffusion weighted MRI. The results showed highly significant correlations between pCASL and DSC CBF measurements (r > = 0.70, p < = 0.0001) and moderately significant correlations between pCASL and DSC CBV measurements (r > = 0.45, p < = 0.027) in both MCA territories and infarct regions. ASL ATT showed correlations with DSC time to the maximum of tissue residual function (Tmax)(r = 0.66, p = 0.0005) and mean transit time (MTT)(r = 0.59, p = 0.0023) in leptomeningeal MCA territories. The present study demonstrated the feasibility for noninvasive multi-parametric perfusion imaging using ASL for acute stroke imaging.

Optimization and Reliability of Multiple Postlabeling Delay Pseudo-Continuous Arterial Spin Labeling during Rest and Stimulus-Induced Functional Task Activation

“…Sequences that account for this variability in arterial arrival time (AAT) can be used to improve the reliability of ASL; thereby supporting its use to image more complex conditions where cerebral perfusion may be undermined by a particular pathology. 21 Recent work supports this by showing that: (1) it is possible to account for heterogeneity in AAT by incorporating multiple PLDs; 22,23 (2) acquisition of multiple PLDs improves the accuracy of CBF quantification by facilitating the removal of the macrovascular component of the ASL signal. 24 At present, no study has assessed the within-and betweensession reproducibility of multi-PLD pCASL.…”

Correlation of 3D Arterial Spin Labeling and Multi-Parametric Dynamic Susceptibility Contrast Perfusion MRI in Brain Tumors

“…According to the previous works, DSC MTT is different from transit time in ASL imaging. ASL transit time is defined as the duration time for the labeled blood between labeling region and brain tissue, whereas DSC MTT represents the mean time for contrast agent to traverse from the arterial to the venous end (19,29). It noted that transit time in ASL is conceptually similar with DSC Tmax.…”

“…In stroke assessment in which the hypoperfused area is identified, good correlations have been shown between ASL and DSC MRI parameters, including Tmax and MTT (8,19). It has also shown that DSC Tmax could assess the effect transit time on ASL perfusion (19).…”

“…It has also shown that DSC Tmax could assess the effect transit time on ASL perfusion (19). The purpose of this study was to compare ASL CBF with DSC MRI parameters including new parameter Tmax, and to assess the influence of transit time in ASL for brain tumors.…”

Operator-bias-free Comparison of Quantitative Perfusion Maps Acquired with Pulsed-continuous Arterial Spin Labeling and Single-photon-emission Computed Tomography

“…ASL has also been reported to provide information regarding the presence of collateral cortical flow using both CASL and PASL. 25,[27][28][29][30] The studies of the teams of Chalela, using CASL, 27 Viallon, using flow-sensitive alternating inversion recovery (FAIR) as an example of a PASL technique, 30 and Wang, using pCASL, 31 reported the cases of patients presenting with hyperperfusion in the ischemic territory. They explained hyperperfusion corresponding to bright intravascular signal with delayed arterial transit and luxury perfusion previously demonstrated by PET study.…”