Brain connectivity in autistic individuals at clinical imaging strengths

Findings from our preliminary investigation, Brain network connectivity in autistic individuals, indicated that autistic individuals exhibit reduced intracellular volume fraction (ICVF) in their white matter (WM). This microstructural feature, detectable using multishell diffusion magnetic resonance imaging (MRI), therefore has potential as a structural biomarker to supplement existing autism diagnostic methods. However, before any further large-scale investigation into ICVF as a biomarker is conducted, it must first be shown that ICVF reductions in autistic individuals are detectable at clinical MRI magnetic field strengths and coarser image resolutions. 

Key project objectives include:

• determining clinical relevance (3T imaging) of data supporting brain microstructural alterations in autistic adults 
• further defining the intracellular volume fraction structural difference by using a combination of scanning techniques to investigate myelin thickness and axon density.

To this end, this project is undertaking a short 3T MRI study that involves the 26 participants from the original preliminary study; 13 autistic and 13 non-autistic individuals (controls). We will also simultaneously investigate whether the diagnostic capabilities of the ICVF analysis can be further augmented via the inclusion of a myelin specific MRI scan in our imaging protocol. This will determine whether previously observed reductions in ICVF are driven by a decrease in neurite density, myelin thinning, or a combination of both factors. Should myelin primarily drive reductions in ICVF, it would invite the possibility of developing potential therapeutic options for autistic individuals in the future.