This case illustrates the dramatic appearance of prolonged and intense contrast staining in a patient who received high contrast volume during DSA and who could not excrete contrast due to chronic renal failure. The initial appearance could easily be mistaken for parenchymal haemorrhage in the region of infarct, and lead to erroneous termination of anticoagulation.

Contrast staining is most commonly seen in gray matter (cortex and deep gray matter) but can involve white matter in up to 20% of patients. Unlike haemorrhage, contrast staining demonstrates lack of surrounding oedema and mass effect, and returns to normal structural appearance after hours to days. Of interest, contrast staining may be a prognostic indicator of brain injury, and there were likely ischaemic changes in both ACA and MCA territories in this patient. According to Amans et al., the majority of patients (86%) with contrast staining progress to ischaemic infarction, but very few (6%) progress to true haemorrhagic transformation. Furthermore, contrast staining is more likely to occur in patients with prolonged period between stroke symptom onset and diagnostic angiogram, i.e. established region of infarction. 

Contrast staining usually resolves by 24 hours post-DSA, but can be significantly prolonged (as in our case) in patients with renal failure.