Quantitative cerebral MR perfusion imaging: preliminary results in stroke

Area of Science:

• Neuroimaging
• Cerebrovascular Medicine
• Radiology

Background:

• Assessing cerebral blood flow (CBF) is crucial for managing ischemic stroke.
• Traditional metrics like time to peak (Tmax) and mean transit time (MTT) have limitations in stroke assessment.
• Quantitative MRI perfusion (qCBF) offers a potential alternative for evaluating cerebral perfusion.

Purpose of the Study:

• To evaluate quantitative cerebral blood flow (qCBF) against traditional time-based metrics (Tmax, MTT) in stroke patients.
• To determine the utility of qCBF in differentiating brain regions with varying degrees of ischemic injury.

Main Methods:

• Nine ischemic stroke patients underwent quantitative MRI perfusion using the Bookend method.
• Regions of interest (ROIs) were defined in critically ischemic (CI), presumed penumbra (PP), and presumed normal (PN) brain tissues.
• Mean values of qCBF, Tmax, and MTT were calculated for gray and white matter separately.

Main Results:

• qCBF measures significantly distinguished between CI and PP tissues, unlike Tmax and MTT.
• Receiver operating characteristic (ROC) analysis showed qCBF had high utility in discriminating between CI and PN regions (AUC=0.96).
• qCBF provided superior discrimination of CI and PP regions compared to Tmax and MTT (AUC=0.82 vs. 0.65 and 0.52).

Conclusions:

• Quantitative MRI perfusion is feasible in ischemic stroke patients.
• qCBF demonstrates enhanced discrimination of critically ischemic and penumbra tissues compared to time-based metrics.
• This qCBF strategy warrants further investigation in larger clinical trials.