Effect of using local arterial input functions on cerebral blood flow estimation

Area of Science:

• Neuroimaging
• Medical Physics
• Radiology

Background:

• Perfusion-weighted MRI (PWI) is crucial for assessing cerebral blood flow (CBF) in stroke.
• Standard PWI methods can be affected by delay and dispersion (D/D) errors.
• Accurate CBF estimation is vital for stroke diagnosis and treatment planning.

Purpose of the Study:

• To evaluate a local arterial input function (AIF) method for PWI CBF estimation in stroke patients.
• To determine if local AIFs can correct D/D errors in CBF calculations.
• To compare local AIF-based CBF with global AIF-based CBF.

Main Methods:

• Dynamic susceptibility contrast data from 36 stroke patients were analyzed.
• CBF maps were generated using both global and local AIF techniques.
• Ratios of local-to-global CBF were calculated and analyzed for voxels with normal and abnormal timing parameters.

Main Results:

• CBF estimates using local AIFs were higher on average in voxels affected by D/D.
• High local-to-global CBF ratios were predominantly found in the ipsilateral hemisphere.
• Concentration-time curves in these voxels confirmed the presence of delay or dispersion.

Conclusions:

• The local-AIF technique effectively increases calculated CBF values in tissues with D/D.
• This suggests that the local-AIF method reduces D/D-associated errors in PWI.
• The findings support the use of local AIFs for more accurate stroke imaging.