P1‐375: utility of mri in the assessment of ad/mci: findings from the ontario neurodegenerative disease research initiative (ondri) study

Current diagnostic criteria for Alzheimer's disease (AD) or Mild Cognitive Impairment (MCI) specifically do not recommend magnetic resonance imaging (MRI) for the diagnostic workup since universally accepted quantitative biomarkers have not been established. MRI can serve an important role in the diagnosis of AD or MCI by identifying comorbid pathologies that may alter treatment or prognosis. We aimed to determine the frequency with which inclusion of clinical review of MRI results detects comorbid vascular and non-vascular pathologies that could impact clinical management or alter findings from clinical trials and whether those with and without incidental findings have different degrees of cognitive impairment or brain atrophy. Hypotheses: There will be >5% of people with potentially important comorbid findings detected on MRI and those with and without comorbid findings (vascular or non-vascular) will differ on measures of cognition, function or medial temporal / hippocampal atrophy. Study sample will include all Ontario Neurodegenerative Disease Research Initiative (ONDRI) screened/consented patients who met diagnostic criteria for AD and MCI and completed an MRI scan. Patients with incidental findings will be identified. The proportion of AD/MCI patients with incidental MRI findings will be established and differences in demographic, neuropsychological, functional and medial temporal/hippocampal brain volume measures between those with and without incidental findings will be examined. One hundred and forty-one patients met clinical criteria for the ONDRI AD/MCI cohort. Preliminary data analysis revealed at least 22 cases (16%) of incidental MRI findings, of which 15 cases (11%) were identified as exclusionary pathology from the AD/MCI cohort. Imaging exclusions included large vessel strokes, smaller strategic infarcts, tumors and prior undisclosed neurosurgeries. Further analysis will elucidate whether those with and without incidental findings have different degrees of cognitive impairment or brain atrophy. The current absence of an MRI requirement in the diagnostic criteria of AD/MCI limits detection of alternate or comorbid conditions that could influence management of AD/MCI as well as comorbid conditions. Diagnostic guidelines should consider endorsing qualitative MRI results in disease diagnosis and management.