IC‐O2‐04: High resolution 7T MR imaging of cerebral small vessel disease

Abstract

Autopsy studies report vascular pathology in the majority of patients with dementia, also in those with a clinical diagnosis of Alzheimer's disease (AD). Vascular co-morbidity in AD is potentially preventable, but we need more sensitive tools to study its etiology and to evaluate the effects of treatment. In this respect, microvascular lesions, in particular microinfarcts and microbleeds are of interest, because they appear to be very common, but may escape detection on regular clinical brain MRI. Ultra high field strength MRI scanners may offer a breakthrough in the detection of microvascular lesions, due to their high spatial resolution and high sensitivity to susceptibility effects. Our group studies small vessel disease on 7T MRI, focusing on microvascular lesions (i.e. microbleeds and microinfarcts), as novel imaging markers of the vascular burden in ageing-related cognitive decline and AD. Our projects involve different study populations, including 1) patients who had an ischaemic stroke, 2) patients with early AD or MCI, 3) patients with type 2 diabetes (a vascular risk factor predisposing to AD) and 4) healthy older controls. Patients (n>200 in total) underwent both a 3T and a 7T MRI scan. The 7T scan (T1-, T2-, and T2*-weighted and FLAIR images) is used for the detection of microvascular lesions and high resolution non-contrast enhanced time-of-flight MR angiography. The 3T scan (3DT1-, T2-, and T2*-weighted, IR, FLAIR, and PD images; DTI; two-dimensional flow-encoded phase-contrast images through the carotid and basilar arteries) is used for automated analyses of brain, cerebrospinal fluid and WMH volumes, DTI analyses of white matter integrity, and assessment of cerebral perfusion. In my presentation I will provide an overview of our 7T MRI studies in these different patient populations. The presentation will address MR angiography, intracranial vascular wall imaging and high resolution measurements of focal atrophy. A particular focus will be on microbleeds and minute cortical infarcts. Patterns of grey matter loss in hippocampal sparing (HpSp), limbic predominant (LP) and typical AD compared to controls (FDR P <0.005)