BACKGROUND:
Treatment guidelines for amyloid therapies mandate MRI scans to monitor for ARIA at regular intervals. As a non-contrast MRI technique that measures cerebral perfusion, arterial spin labelling (ASL) can be readily included in existing ARIA monitoring sessions with little change to workflows. This abstract builds upon prior work to demonstrate the suitability of ASL MRI to track and predict cognitive change during amyloid therapy.
METHODS:
Data were collected from 13 patients (5M 8F, aged 73.4 ± 8.6 years) undergoing amyloid therapy at Weill Cornell Medicine, New York, USA. T1-weighted structural and ASL images were acquired at baseline and during ARIA monitoring sessions on GE 3T scanners. Pseudo-continuous ASL (PCASL) was used with a 1.8s label duration, 2.025s post-label delay, 3D readout and TR/TE = 5.338s/53.6ms. Cognition was assessed using MOCA before and during treatment, with change in MOCA used to measure treatment response. T1w images were processed using recon-all-clinical from FreeSurfer 7.4.1 to segment the Desikan-Killiany-Tourville (DKT) atlas structures. ASL images were processed using the QASL pipeline (Quantified Imaging, UK), a derivative of FSL’s BASIL to quantify cerebral blood flow (CBF). To mitigate the effect of demographics on baseline CBF, each subject’s map was normalised to a value of 60 units using a reference region method. Pearson’s correlation was calculated between MOCA change and mean whole-brain cortical CBF change. Additionally, baseline regional CBF was correlated against cognition change to assess the predictability of treatment response.
RESULTS:
Change in mean whole-brain cortical CBF correlated significantly with change in cognition (r=0.90, p<0.001). Among the 62 cortical structures in the DKT atlas, the right entorhinal cortex showed the strongest correlation between baseline CBF and change in MOCA (r=0.75, p=0.003).
CONCLUSION:
In a small cohort, changes in cortical CBF from ASL MRI showed an excellent correlation with changes in MOCA during amyloid therapy. Further, right entorhinal CBF at baseline correlated well with future cognition change, demonstrating that ASL may be used to predict treatment response. Further work is needed to validate these findings in a larger cohort, with the aim of establishing ASL as a valuable tool for monitoring and predicting treatment outcomes.