Figure 3

Blood oxygen level-dependent magnetic resonance imaging (BOLD MRI) in severe occlusive disease of the left kidney. T2 imaging by CT angiogram (a) and T2 MRI (b) demonstrating severe renal-artery stenosis (left kidney) and presence of a stent in the contralateral kidney. (c) and (d) Parametric maps of R2* (reflecting the deoxyhemoglobin level) from BOLD MRI in the same patient. In the right kidney ([c] normal, well-perfused), most of the cortex shows low R2* signal (blue) and there are some small areas with a high R2* signal in the medulla (red). Conversely, in the left kidney ([d] vascular compromise), there are higher levels of cortical R2* indicating the presence of more deoxygenated blood and a large, deep area with a high R2* signal (deoxygenated hemoglobin) in the medulla (from [75] with permission).