Magnetic resonance angiography and perfusion. Gcdh
−/− and WT mice underwent MR perfusion-weighted imaging and angiography before and after lysine diet exposure. a Representative images showing index of cerebral blood flow (ICBF) as colorimetric scale (0–600 ml/100 mg tissue/ min). After 72-hours of lysine diet exposure, Gcdh
−/− mouse shows reduced ICBF bilaterally in the striatum (ICBF < 300 ml/100 mg tissue/min). After 96-hours, Gcdh
−/− mouse has globally reduced ICBF (< 200 ml/100 mg tissue/min). b Normal visualization of circle of Willis, with vertebral (VA), basilar (BA), posterior (PCA), middle (MCA) and anterior (ACA) cerebral arteries from bottom up in WT and Gcdh
−/− mouse on a standard diet (SD). Complete loss of signal in Gcdh
−/− mouse brain is noted after 96-hours of lysine diet using standard acquisition time (19 ms). Note signal from carotid arteries (large arrow) and circle of Willis (small arrow). Using 5-fold longer acquisition time (100 ms) a small area of the posterior circulation is visible just above the carotid arteries (large arrow). c Quantitative ICBF changes were significant in cortical and striatal ICBF in WT (n = 4) and Gcdh
−/− mice (n = 5) following lysine diet exposure (* p < 0.05 t-test, **p < 0.05 ANOVA with repeated measures).