Contrast Agent Dose Effects in Cerebral Dynamic Susceptibility Contrast Magnetic Resonance Perfusion Imaging

Purpose: To study the contrast. agent dose sensitivity of hemodynamic parameters derived from brain dynamic susceptibility contrast MRI (DSC-MRI). Materials and Methods: Sequential DSC-MRI (1.5T gradient-echo echo-planar imaging using an echo time of 61-64 msec) was performed using contrast agent closes of 0.1 and 0.2 mmol/kg delivered at a fixed rate of 5.0 mL/second ill 12 normal subjects and 12 stroke patients. Results: 1) Arterial signal showed the expected doubling in relaxation response (Delta R2*) to dose doubling. 2) The brain signal showed a less than doubled Delta R2* response to dose doubling. 3) The 0.2 mmol/kg dose Studies subtly underestimated cerebral blood volume (CBV) and cerebral blood flow (CBF) relative to the 0.1 mmol/kg studies. 4) In the range of low CBV and CBF. the 0.2 mmol/kg studies over-estimated the CBV and CBF compared with the 0.1 niniol/kg studies. 5) The 0.1 mmol/kg studies reported larger ischemic Volumes in stroke. Conclusion: Subtle but statistically significant dose sensitivities were found. Therefore. it is advisable to carefully control the contrast agent dose when DSC-MRI is used in clinical trials. The study also suggests that a 0.1 mmol/kg dose is adequate for hemodynamic measurements.