Jackie Leung, Presenter: Nothing to Disclose

Jaichander Swaminathan, Abstract Co-Author: Nothing to Disclose

Adrian P. Crawley PhD, Abstract Co-Author: Nothing to Disclose

Andrea Kassner PhD, Abstract Co-Author: Nothing to Disclose

We have shown a linear relation between the extent of cortical thinning and reduced CVR in children with SCD in specific regions of the brain. This regionally dependent correlation could indicate that certain cortical areas are particularly sensitive to disruptions in normal blood flow regulation.

Sickle cell disease (SCD) is a genetic life-long disorder with a significant rate of neurological complications. There is growing evidence that children with SCD are cognitively impaired despite normal conventional MRI exams. Recently, the measurement of cerebrovascular reactivity (CVR), defined as a change in cerebral blood flow in response to a vasoactive stimulus, using MRI has demonstrated potential in the assessment of these patients. Compared to healthy controls, SCD patients have exhibited globally reduced CVR even in cases with no visible ischemic injury on conventional MRI. However, it is not known whether reduced CVR has a physiological impact on cortical integrity and could serve as a biomarker of cognitive decline.

Six pediatric patients with SCD (age 13-18 years) and five healthy controls were imaged on a clinical 3T MRI scanner. BOLD-CVR was acquired in combination with a computer-controlled gas sequencer, which delivered the vasoactive stimulus, CO2, via a rebreathing mask. T1-weighted anatomical images were also acquired. CVR maps were computed using FSL by correlating the voxel-wise BOLD signal change to the measured end-tidal CO2 waveform, followed by coregistration to the anatomical space. Using Freesurfer, the anatomical T1 data was converted into cortical thickness surface maps and the CVR volume data was projected onto the pial surface. The Desikan-Killiany atlas was used to partition the cortical surface into 34 subregions for each dataset. CVR and cortical thickness data were normalized and a correlation analysis was performed for each region.

Of the 34 cortical subregions, 31 had a lower average cortical thickness in SCD patients compared to healthy controls. The regional correlation analysis identified multiple regions where cortical thickness showed a dependence on CVR, especially in the precentral, paracentral, and inferior parietal regions.

Leung, J, Swaminathan, J, Crawley, A, Kassner, A, Reduced Cerebrovascular Reactivity Is Associated with Cortical Thinning in Patients with Sickle Cell Disease.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12022880.html