A comparison study between the saturation-recovery-T₁ and CASL MRI methods for quantitative CBF imaging

Area of Science:

• Magnetic Resonance Imaging
• Neuroscience
• Physiology

Background:

• Cerebral blood flow (CBF) is a critical physiological parameter.
• Accurate and quantitative CBF measurement is essential for understanding brain function and disease.
• Existing methods for CBF quantification have limitations.

Purpose of the Study:

• To compare the novel saturation-recovery T1 (SR-T1) MRI method for CBF change (ΔCBF) quantification with a continuous arterial spin labeling (CASL) approach.
• To validate the SR-T1 MRI method in normal and middle cerebral artery occlusion (MCAo) rat models.
• To determine the intrinsic longitudinal relaxation rate (R1int) in vivo.

Main Methods:

• SR-T1 MRI was used to measure ΔCBF during hypercapnia in rat models.
• CASL MRI was employed as a reference perfusion imaging method.
• Experimental determination of R1int by comparing R1app and CBF measurements.

Main Results:

• Excellent agreement was observed between ΔCBF values measured by SR-T1 MRI and CASL.
• The intrinsic longitudinal relaxation rate (R1int) was successfully determined in vivo.
• The study validated the relationship between brain tissue water relaxation rates and cerebral perfusion.

Conclusions:

• The SR-T1 MRI method provides a feasible and accurate approach for quantitative in vivo imaging of CBF and its changes.
• This method holds promise for clinical applications in assessing cerebrovascular health.
• The determination of R1int enables direct CBF calculation from R1app measurements in healthy brain.