Method for improving the accuracy of quantitative cerebral perfusion imaging

Area of Science:

• Neuroimaging
• Medical Physics
• Radiology

Background:

• Dynamic susceptibility contrast (DSC) perfusion imaging is crucial for assessing cerebral blood flow (CBF) and cerebral blood volume (CBV).
• Standard DSC methods can exhibit variability, impacting diagnostic accuracy, particularly in conditions like acute stroke.
• Improving the precision of DSC measurements is essential for reliable clinical interpretation.

Purpose of the Study:

• To enhance the accuracy of dynamic susceptibility contrast (DSC) measurements for cerebral blood flow (CBF) and cerebral blood volume (CBV).
• To introduce a calibration method using steady-state CBV (CBV(SS)) to refine standard DSC perfusion assessments.
• To reduce measurement variability in CBF and CBV for improved clinical utility.

Main Methods:

• Steady-state CBV (CBV(SS)) was measured using TrueFISP readout of inversion recovery (IR) in eight volunteers.
• Standard DSC perfusion measurements were performed using echo-planar imaging (EPI) during contrast bolus passage.
• A subject-by-subject calibration was applied by using the ratio of CBV(SS) to DSC-derived CBV (CBV(DSC)) to adjust CBF and CBV values.

Main Results:

• Calibrated CBV and CBF values showed improved agreement with published gold-standard data.
• A significant reduction in the variability of CBV measurements was observed in both white matter (WM) (P < 0.001) and gray matter (GM) (P < 0.03) after calibration.
• Calibration led to a significant reduction in the variability of CBF measurements in WM (P < 0.0001).

Conclusions:

• Integrating a CBV(SS) measurement with standard DSC perfusion imaging enhances the accuracy of CBF and CBV quantification.
• The proposed calibration method offers a more reliable approach to assessing cerebral perfusion.
• This refined DSC technique holds promise for evaluating patients with acute stroke and other cerebrovascular conditions.