Arterial spin labeling compared to dynamic susceptibility contrast MR perfusion imaging for assessment of ischemic penumbra: A systematic review

Abstract

Background and Purpose: Dynamic susceptibility contrast (DSC) MR imaging is commonly used to estimate penumbra size in acute ischemic stroke; this technique relies on the administration of gadolinium contrast, which has limited use in certain populations, such as those with impaired renal function or allergies. Arterial spin labeling (ASL) is a relatively new technique that can provide information on cerebral perfusion without need for exogenous contrast agents. This systematic review examines published studies that specifically compared ASL to DSC for assessment of ischemic penumbra. Methods:We searched PubMed, Embase, Web of Science, and the Cochrane Library for papers which compared ASL with DSC for assessment of ischemic penumbra in acute ischemic stroke among adult human populations. Two independent reviewers screened studies using predefined inclusion and exclusion criteria. Study characteristics and findings regarding the utility of ASL compared to DSC for identification of penumbra were then extracted and anlyzed for results and risk of bias. Results: Seventeen articles met inclusion and exclusion criteria. Studies compared ASLwith DSC on a range of metrics (hypoperfusion, hyperperfusion, mismatch, and reperfusion). Most studies concluded that agreement of ASL with DSC was moderate to very high.A small subset of studies found discrepancy in agreement of ASL with DSC for size or location of perfusion abnormalities. A heterogeneity of perfusion parameters studied for DSC was noted, along with the need for more standardization of research methods. Conclusion:ASL shows moderate to high agreement with DSC for detection of penumbra among ischemic stroke patients.

Acute Ischemic Stroke in Pregnancy

“…It is also reasonable to utilize arterial spin labeling (ASL) MRI as a noninvasive, non-contrast technique that enables not only cerebral blood flow (CBF), but also occlusion site and collateral flow evaluation [45]. In a systematic review by Liu et al the agreement on several metrics (hypoperfusion, hyperperfusion, mismatch, and reper-fusion) for ASL and DSC was concluded to be moderate to very high, with some heterogeneity of perfusion parameters in analyzed studies [46]. ASL-MRP is a valuable imaging method in certain populations with contraindications for contrast administration, including childbearing women in cases of AIS.…”

Advances in cerebral perfusion imaging techniques in acute ischemic stroke

“…Indeed, Rivard et al 55 discovered that ASL underestimated CBF in hypoperfused white matter. Moreover, Liu et al 56 reported that ASL and DSC have moderate to high consistency in estimating the penumbra in AIS. This study also demonstrated that DSC had higher relative cerebral blood flow than ASL in hypoperfused areas after recanalization, whereas a comparison revealed that the findings of ASL and DSC were comparable before reperfusion, implying that ASL may underperform in the presence of minor perfusion abnormalities.…”

Arterial Spin Labeling technique and clinical applications of the intracranial compartment in stroke and stroke mimics - A case-based review

“…MRI perfusion (MRP) techniques can improve selection of acute ischemic stroke patients for treatment by estimating this salvageable area of decreased perfusion. 1,2,10,14 There are several approaches to quantifying penumbra. Dynamic susceptibility contrast (DSC) MR imaging is a first-pass technique that relies on injection of a gadolinium-based contrast agent (GBCA).…”

“…DSC is commonly used to assess penumbra size in acute ischemic stroke. 8,[14][15][16][17] DSC is a very rapid scan (∼2 min), relatively robust to motion artefact, and available in most stroke centers. The main disadvantage of DSC is requiring IV contrast meaning it requires durable intravenous access for power injection of contrast, which is often unavailable in people with chronic disease or injection drug abuse history.…”