Journal Article

Spontaneous BOLD Signal Fluctuations in Young Healthy Subjects and Elderly Patients with Chronic Kidney Disease

Tamura, Manjula Kurella, Jahanian, Hesamoddin, Ni, Wendy W., Zaharchuk, Greg, Moseley, Michael E., Christen, Thomas

2014

Overview

Spontaneous fluctuations in blood oxygenation level-dependent (BOLD) images are the basis of resting-state fMRI and frequently used for functional connectivity studies. However, there may be intrinsic information in the amplitudes of these fluctuations. We investigated the possibility of using the amplitude of spontaneous BOLD signal fluctuations as a biomarker for cerebral vasomotor reactivity. We compared the coefficient of variation (CV) of the time series (defined as the temporal standard deviation of the time series divided by the mean signal intensity) in two populations: 1) Ten young healthy adults and 2) Ten hypertensive elderly subjects with chronic kidney disease (CKD). We found a statistically significant increase (P<0.01) in the CV values for the CKD patients compared with the young healthy adults in both gray matter (GM) and white matter (WM). The difference was independent of the exact segmentation method, became more significant after correcting for physiological signals using RETROICOR, and mainly arose from very low frequency components of the BOLD signal fluctuation (f<0.025 Hz). Furthermore, there was a strong relationship between WM and GM signal fluctuation CV's (R(2)= 0.87) in individuals, with a ratio of about 1:3. These results suggest that amplitude of the spontaneous BOLD signal fluctuations may be used to assess the cerebrovascular reactivity mechanisms and provide valuable information about variations with age and different disease states.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Adult / Adults / Age / Aged / Aged, 80 and over / Aging / Bioindicators / Biology and Life Sciences / Biomarkers / Blood / Blood Pressure / Brain - blood supply / Brain - physiology / Brain research / Cerebrovascular system / Chronic kidney failure / Coefficient of variation / Comparative analysis / Diabetes / Elderly patients / Engineering and Technology / Female / Fluctuations / Functional magnetic resonance imaging / Geriatrics / Glomerular Filtration Rate / Humans / Hypertension / Hypertension - diagnosis / Hypertension - metabolism / Image Interpretation, Computer-Assisted / Image processing / Image segmentation / Kidney diseases / Kidney transplantation / Kidneys / Magnetic Resonance Imaging / Male / Medicine and Health Sciences / Mens health / Metabolism / Middle Aged / Older people / Oximetry - methods / Oxygen - metabolism / Oxygenation / Patients / Physiological aspects / Physiology / Prospective Studies / Renal Insufficiency, Chronic - diagnosis / Renal Insufficiency, Chronic - metabolism / Review boards / Segmentation / Statistical analysis / Studies / Substantia alba / Substantia grisea / Time series / Young Adult