Imaging Alzheimer in 2011

Integrative biomarker discovery in neurodegenerative diseases

“…In AD, a large number of studies considered imaging data as potential biomarkers . sMRI is used to assess diagnostic biomarkers such as brain atrophy and volume . Nonetheless, structural analysis is not sufficient as an AD diagnostic tool, especially considering the poor sensitivity to discriminate MCI patients converting to dementia from non converters .…”

“…Even though several studies report FDG–PET as having a better sensitivity to detect conversion to dementia, SPECT has shown higher specificity to AD . Moreover, the combination of several imaging modalities, as MRI, PET, and Dopamine SPECT, can help to differentiate AD from other types of dementia [such as FTD and dementia with Lewy bodies (DLB)] …”

“…23 Low levels of proteins such as A -42 and high levels of phosphorylated tau (as well as total tau) in CSF have revealed potential biomarkers for AD. 7,23,47,49,50,[79][80][81][82] However, the CSF tau/A -42 ratio yielded a greater diagnostic power, increasing both the sensitivity and specificity to distinguish AD from other dementias in early stages. 23 This highlighted the potential of using a simple biomarker integration in diagnosis improvement.…”

“…One of the most prominent brain changes associated to aging is an atrophy resulting from synaptic and neuronal loss, which is generally more pronounced in patients with dementia, and detectable using these data. 23 Concerning neuroimaging techniques, we highlight methods such as computed tomography (CT), 23,81,90 transcranial sonography (TCS), 84,91 structural and functional magnetic resonance imaging (s/fMRI), 23,59,90,91 including diffusion-weighted imaging, 90 DTI 59,90,91 and arterial spin labeling (ASL) perfusion 90 ; as well as PET 23,49,79,[90][91][92] and single-photon emission computed tomography (SPECT). 23,90,91 Structural imaging techniques, such as CT and sMRI, are usually useful to rule out different causes of dementia, such as normal pressure hydrocephalus or tumors.…”

“…8,23,90 sMRI is used to assess diagnostic biomarkers such as brain atrophy and volume. 23,81,90,92 Nonetheless, structural analysis is not sufficient as an AD diagnostic tool, 90 especially considering the poor sensitivity to discriminate MCI patients converting to dementia from non converters. 23,90 Functional MRI was used in several studies to indirectly measure brain activity, with individuals with AD generally presenting a decreased brain activity in parietal and hippocampal regions, 23 as well as in the medial temporal lobe.…”