MRI Detects Oxidative Stress Induced by Methaemoglobin

Fluorescence than Ferrous Hb In the absence of haemoglobin (Hb) products, no cisparinaric Acid (PnA) fluorescence is lost. However, upon addition of ferrous Hb, there is an increasing amount of fluorescence lost. Substantial fluorescence quenching is seen on the addition of extracellular mHb, with significantly less using an intracellular product. This suggests that the cellular membrane is an important inhibitor of lipid oxidation via Hb sequestration. Error bars are standard deviation of the mean from three separate trials. PnA is a mixture of LDL and cis-parinaric acid, H2O2 is hydrogen peroxide, X is the PnA, LDL and H2O2 solution, oHb is oxyhaemoglobin, dHb deoxyhaemoglobin and mHb methaemoglobin. The e prefix indicates extracellular. Figure 1: MR Detected Intraplaque Haemorrhage Identifies Patients with Increased Risk of Cerebrovascular Events Independent of Stenosis Panel A shows a coronal slice of a T1 weighted three dimensional, spoiled gradient echo volume that is fat and flow suppressed. Focal T1 hyperintensity, denoted by the arrowhead, appearing in the left carotid bifurcation is indicative of intraplaque haemorrhage in the arterial wall. Furthermore, natural history trials have correlated this presentation to an increased risk of future clinical events. Inset is a bright blood MR angiogram showing stenosis at the carotid bifurcation of the same artery. This level of stenosis is similar to that of the stenosis seen in the inset of panel B. However, despite having similar stenosis, the absence of a T1 hypertintense signal is suggestive of stable plaque morphology.