Alzheimer's Disease

Recent clinical trials for treating Alzheimer’s Disease (AD) have achieved the reduction of amyloid burden but this has not resulted in cognitive improvement. Thus, many AD investigators believe that the pathological processes must be attacked before the cognitive phenotype is manifest, while damage is still reversible or can be minimized1. In this context, the development of predictive biomarkers and models is critical for identifying patients with high risk of rapid progression along the AD continuum, i.e. transitioning from normal cognition to mild cognitive impairment (MCI) and from MCI to dementia. Emory Brain Imgaging Project is a component of the Emory Healthy Brain Study . It is jointly led by Drs Deqiang Qiu and Bruce Crosson and aims to develop imaging biomarkers that can predict the risk of conversion.

Stroke Imaging

Stroke is the fifth leading cause of death, and the leading cause of adult disability in the U.S. Imaging plays an important role in the management of acute stroke. We are interested in developing imaging methods in stratifying risks of secondary stroke among patients with stenosis or occlusion of carotid or intracranial arteries. Our strategy to addressing this problem is through measurement of cerebrovascular reactivity using both Acetozolamide and CO2 gas challenge as vasodilatory stimuli and novel MRI imaging techniques.

Diamox CVR

Machine Learning

Machine learning, particularly with the recent popularity of deep convolutional neural networks, has become a powerful tool for many areas, we have started working on using ML for image reconstruction, segmentation as well as disease diagnosis and prognosis.

Chen S, Qi K, Qiu D. Is MRI all we need? Prediction of conversion between normal cognitive function, mild cognitive impairment and Alzheimer’s disease. Proceeding of International Society of Magnetic Resonance in Medicine 26th Annual Meeting. June 2018

Cerebrovascular Reactivity

Perfusion and Blood Brain Barrier Imaging

The measurement of cerebral blood flow, cerebral blood volume as well as cerebral permeability provides important insights into different neurological diseases, including tumors, multiple sclerosis, and Alzheimer's Disease. We have developed a novel multi-band multi-echo EPI (M2-EPI) sequence for simultaneous perfusion (CBF, CBV) and permeability imaging.

M2-EPI

Wu J, Saindane AM, Zhong X, Qiu D. Simultaneous perfusion and permeability assessments using multiband multi-echo EPI (M2-EPI) in brain tumors. Magn Reson Med. 2018 Oct 9. doi: 10.1002/mrm.27532.

Magnetic Susceptibility Imaging

Quantitative susceptibility mapping is an MR imaging technique that provides semi-quantitative measures of magnetic susceptibility values of tissues. In the brain, the primary source of magnetic susceptibility contrast comes from iron content, myelin and deoxygenated hemoglobin. We have used susceptibility imaging to measure oxygenation extraction fraction with and without Acetazolamide in patients with cerebrovascular disease

QSM OEF

Leatherday C, Dehkharghani S, Nahab F, Allen JW, Wu J, Hu R, Qiu D. Cerebral MR oximetry during acetazolamide augmentation: Beyond cerebrovascular reactivity in hemodynamic failure. JMRI. 2018

Quantitative Magnetic Resonance Imaging (qMRI)

Quantitative magnetic resonance imaging (qMRI) provides quantitative measurements of specific physical properties related to focal tissue microstructures. qMRI parameters include longitudinal and transverse relaxation rates (R1 and R2), effective transverse relaxation rates (R2*), magnetic susceptibility, magnetization transfer (MT), and proton density, etc. These parameters carry important information about the tissue microstructures such as iron content, myelination, cellularity, cell membranes and tissue composition in brain tissue. In one of our recent studies (Lin et al., 2023), we used quantitative MR relaxometry and CSF biomarker data from human volunteers to explore iron accumulation in the brain as an early biomarker for Alzheimer’s disease. Our study revealed significant iron over-accumulation in subcortical regions in asymptomatic AD participants and the elevated iron content was associated with neuropsychological performance primarily related to visuospatial functions.

R2* ALL

Lin Q, Shahid S, Hone‐Blanchet A, Huang S, Wu J, Bisht A, Loring D, Goldstein F, Levey A, Crosson B, Lah J, Qiu D. Magnetic resonance evidence of increased iron content in subcortical brain regions in asymptomatic Alzheimer's disease. Human Brain Mapping. 2023 Jun 1;44(8):3072-83.

Magnetic Resonance Spectroscopy (MRS)

Magnetic Resonance Spectroscopy (MRS) is an MR-based technique that noninvasively allows estimation of concentrations of various brain metabolites in vivo within a voxel of interest, including myo-inositol (mI), gamma-aminobutyric acid (GABA), glutamate+glutamine (Glu+Gln; Glx), creatine (Cr) and phosphocreatine (PCr), choline (Cho) and n-acetylaspartate (NAA). Our two recent studies used MRS techniques to study the frontal metabolites in cognitively normal older adults (Hone-Blanchet et al., 2022a) and mild cognitive impairment (MCI) patients (Hone-Blanchet et al., 2022b). These studies demonstrated age- and biomarker-related changes in brain metabolites in both healthy aging and early Alzheimer's disease.

MRS ALL

Hone-Blanchet A, Bohsali A, Krishnamurthy LC, Shahid S, Lin Q, Zhao L, Loring D, Goldstein F, John SE, Fleischer CC, Levey A, Lah J, Qiu D, Crosson B. Relationships between frontal metabolites and Alzheimer's disease biomarkers in cognitively normal older adults. Neurobiology of Aging. 2022 Jan 1;109:22-30.

Hone-Blanchet A, Bohsali A, Krishnamurthy LC, Shahid S, Lin Q, Zhao L,Bisht A, Samantha E, Loring D, Goldstein F, Levey A, Lah J, Qiu D, Crosson B. Frontal metabolites and Alzheimer’s disease biomarkers in healthy older women and women diagnosed with mild cognitive impairment. Journal of Alzheimer's Disease. 2022 Jan 1;87(3):1131-41.