Thangamadhan Bosemani
Our research team has focused on the clinical applications of advanced neuroimaging techniques, such as susceptibility-weighted imaging (SWI) in the evaluation of pediatric neurologic disorders. SWI provides useful functional information about blood oxygenation levels in intracranial vessels. In pediatric arterial ischemic stroke (PAIS), SWI focusing on venous drainage can provide noninvasive information about the degree of brain perfusion. We evaluated the influence of the SWI venous signal pattern in predicting stroke evolution.
The ischemic penumbra can be classically depicted as a mismatch between reduced perfusion and normal diffusion and represents salvageable brain tissue. In terms of long-term neurologic outcome, it is important to obtain information about ischemic penumbra quickly (time is brain) and easily (noninvasively, particularly in the pediatric population). In a large cohort of children with PAIS, we performed a semiquantitative analysis of venous signal intensity on SWI and diffusion characteristics on diffusion tensor imaging (DTI) in 16 vascular territories. Instead of reduced perfusion, we compared regions with SWI hypointense veins (increased content of deoxygenated blood) and regions of reduced diffusion to depict a SWI/DTI mismatch. Our results show that a mismatch between vascular territories with SWI-hypointense venous signal and restricted diffusion is associated with infarct progression in PAIS.
Our findings show that in PAIS, SWI provides valuable, time-sensitive, noninvasive information about salvageable brain tissue and may guide early treatment options to prevent infarct progression. In the pediatric population, this is of increasing relevance because multicenter international trials are assessing safety and necessary dose of intravenous tPA. In our hospital,