fig 1.

58-year-old man with neurosyphilis and progressive neurologic symptoms. SPECT scans before right MCA angioplasty show relatively normal baseline perfusion (top row) but significantly decreased perfusion in the right ACA, MCA, and PCA territories after acetazolamide administration (bottom row), consistent with decreased rCVR. (The printed color scale representing brain perfusion is different from the linear 10-level color scale used for interpreting nuclear medicine studies; however, it allows easier comparison with fig 3.)