Methods Patients undergoing clinically indicated coronary angiography underwent BOLD CMR scans using a clinical 1.5T scanner. Three short axis BOLD cine images were captured at baseline and during adenosine-induced coronary hyperemia. The mean segmental percent signal intensity (SI) changes were calculated between baseline and hyperemia in the subendocardial myocardium using the 16-segment mode...

Introduction: The blood oxygen level dependent (BOLD) effect is a potential mechanism for clinical measurement of myocardial perfusion reserve. During vasodilation, increased blood flow to the myocardium causes an increase in the venous blood oxygen saturation resulting in an increase in T2* and T2 relaxation times. In the past, cardiac BOLD imaging has been plagued by artifacts caused by low s...

Introduction Studies on humans at clinical field strengths have shown that the blood oxygen level dependent (BOLD) effect is increased in images acquired with pulse sequences detecting intermolecular multiple-quantum coherences (iMQC). Recently, hyperoxia-induced global BOLD contrast was observed in anesthetized mice [1] and rats [2] with the novel iMQC-imaging sequence TurboCRAZED. The aim of ...

Introduction: Blood-oxygen-level dependent (BOLD) MRI may be used for detecting myocardial oxygenation changes secondary to coronary artery stenosis (CAS) (1-3). Under pharmacological stress, areas of the myocardium supplied by a stenotic coronary artery appear hypointense relative to healthy regions in BOLD images. Manual windowing is often required to visualize these changes and segmentation ...

Methylene blue USP (MB) at low doses has metabolic-enhancing and antioxidant properties and exhibits experimental neurotherapeutic benefits, but little is known about its in vivo effects on cerebral blood flow (CBF), functional evoked responses, and the associated changes in cerebral metabolic rate of oxygen (CMRO2). This study used magnetic resonance imaging (MRI) to evaluate the in vivo effec...

Imbalance between renal oxygen delivery and demand in the first hours after reperfusion is suggested to be decisive in the pathophysiological chain of events leading to ischemia-induced acute kidney injury. Here we describe blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) for continuous monitoring of the deoxyhemoglobin-sensitive MR parameter T 2* in the renal cortex, o...

Background/purpose Blood oxygen level-dependent (BOLD) cardiac MRI (CMR) uses the signal generated by endogenous hemoglobin in the blood supply to directly measure tissue oxygenation. Therefore it may be useful as a non-contrast enhanced, non-invasive method to detect the presence of myocardial ischemia in patients suspected of having coronary artery disease (CAD). The aim of this study was to ...

Brain oscillatory activity has long been thought to have spatial properties, the details of which are unresolved. Here we examine spatial organizational rules for the human brain oscillatory activity as measured by blood oxygen level-dependent (BOLD) signal. Resting-state BOLD signal was transformed into frequency space (Welch's method) and averaged across subjects, and its spatial distribution...

The effect of relative language proficiency on the spatial distribution and magnitude of BOLD signal change was evaluated by studying two groups of right-handed English-Mandarin bilingual participants with contrasting language proficiencies as they made semantic judgments with words and characters. Greater language proficiency corresponded to shorter response times and greater accuracy in the s...

Introduction Coherent spontaneous hemodynamic fluctuations have been widely observed in many brain networks of different species, and they were hypothesized to reflect underlying “functional connectivity” [1] of the brain and imply many “resting networks” . Since it is known that the anesthesia can significantly affect brain activity and state; it can probably also influence these resting netwo...