Hyperintense acute reperfusion marker is associated with higher contrast agent dosage in acute ischaemic stroke.

Objective: The hyperintense acute reperfusion marker (HARM) on fluid-attenuated inversion recovery (FLAIR) images is associated with blood-brain barrier (BBB) permeability changes. The aim of this study was to examine the influence of contrast agent dosage on HARM incidence in acute ischaemic stroke patients.

Methods: We prospectively included 529 acute ischaemic stroke patients (204 females, median age 71 years). Patients underwent a first stroke-MRI within 24 hours from symptom onset and had a follow-up on day 2. The contrast agent Gadobutrol was administered to the patients for perfusion imaging or MR angiography. The total dosage was calculated as ml/kg body weight and ranged between 0.04 and 0.31 mmol/kg on the first examination. The incidence of HARM was evaluated on day 2 FLAIR images.

Results: HARM was detected in 97 patients (18.3%). HARM incidence increased significantly with increasing dosages of Gadobutrol. Also, HARM positive patients were significantly older. HARM was not an independent predictor of worse clinical outcome, and we did not find an association with increase risk of haemorrhagic transformation.

Conclusions: A higher dosage of Gadobutrol in acute stroke patients on initial MRI is associated with increased HARM incidence on follow-up. MRI studies on BBB should therefore standardize contrast agent dosages.

Key Points: • Hyperintense acute reperfusion marker on MRI indicates blood-brain barrier disruption. • This observational study on stroke patients characterizes HARM. • Incidence depends on contrast agent dosage on the previous day. • HARM is also associated with older age and poor kidney function. • Interpretation of HARM must take dosage into consideration.