Figure 12:82-year-old male with bilateral carotid artery stenosis.
(A) NCCT is normal.
(B) CTA-SI reveals calcified plaque at the carotid artery bifurcations bilaterally (arrows), with associated severe stenosis.
(C) CTP baseline study shows no focal perfusion abnormality.
(D) CTP after Diamox challenge demonstrates normal robust increased CBF and CBV diffusely, consistent with an intact cerebrovascular reserve capacity. Note: MTT may slightly decrease or remain unchanged, as per the calculation of MTT from the Central Volume Principle.