Articles by Emily C. Bush in JoVE
Fat-Water Phantoms for Magnetic Resonance Imaging Validation: A Flexible and Scalable Protocol Emily C. Bush1, Aliya Gifford2, Crystal L. Coolbaugh1, Theodore F. Towse1,3,4, Bruce M. Damon1,5,6,7, E. Brian Welch1,5 1Vanderbilt University Institute of Imaging Science (VUIIS), Vanderbilt University Medical Center, 2Department of Biomedical Informatics, Vanderbilt University Medical Center, 3Department of Physical Medicine and Rehabilitation, Vanderbilt University Medical Center, 4Department of Biomedical Sciences, Grand Valley State University, 5Department of Radiology & Radiological Sciences, Vanderbilt University Medical Center, 6Department of Biomedical Engineering, Vanderbilt University, 7Department of Molecular Physiology and Biophysics, Vanderbilt University The purpose of this work is to describe a protocol for creating a practical fat-water phantom that can be customized to produce phantoms with varying fat percentages and volumes.
Other articles by Emily C. Bush on PubMed
Comparison of Muscle BOLD Responses to Arterial Occlusion at 3 and 7 Tesla Magnetic Resonance in Medicine. Mar, 2016 | Pubmed ID: 25884888 The purpose of this study was to determine the feasibility of muscle BOLD (mBOLD) imaging at 7 Tesla (T) by comparing the changes in R2* of muscle at 3 and 7T in response to a brief period of tourniquet-induced ischemia.
Post-contractile BOLD Contrast in Skeletal Muscle at 7 T Reveals Inter-individual Heterogeneity in the Physiological Responses to Muscle Contraction NMR in Biomedicine. Dec, 2016 | Pubmed ID: 27753155 Muscle blood oxygenation-level dependent (BOLD) contrast is greater in magnitude and potentially more influenced by extravascular BOLD mechanisms at 7 T than it is at lower field strengths. Muscle BOLD imaging of muscle contractions at 7 T could, therefore, provide greater or different contrast than at 3 T. The purpose of this study was to evaluate the feasibility of using BOLD imaging at 7 T to assess the physiological responses to in vivo muscle contractions. Thirteen subjects (four females) performed a series of isometric contractions of the calf muscles while being scanned in a Philips Achieva 7 T human imager. Following 2 s maximal isometric plantarflexion contractions, BOLD signal transients ranging from 0.3 to 7.0% of the pre-contraction signal intensity were observed in the soleus muscle. We observed considerable inter-subject variability in both the magnitude and time course of the muscle BOLD signal. A subset of subjects (n = 7) repeated the contraction protocol at two different repetition times (TR : 1000 and 2500 ms) to determine the potential of T1 -related inflow effects on the magnitude of the post-contractile BOLD response. Consistent with previous reports, there was no difference in the magnitude of the responses for the two TR values (3.8 ± 0.9 versus 4.0 ± 0.6% for TR = 1000 and 2500 ms, respectively; mean ± standard error). These results demonstrate that studies of the muscle BOLD responses to contractions are feasible at 7 T. Compared with studies at lower field strengths, post-contractile 7 T muscle BOLD contrast may afford greater insight into microvascular function and dysfunction.
An Individualized, Perception-Based Protocol to Investigate Human Physiological Responses to Cooling Frontiers in Physiology. 2018 | Pubmed ID: 29593558 Cold exposure, a known stimulant of the thermogenic effects of brown adipose tissue (BAT), is the most widely used method to study BAT physiology in adult humans. Recently, individualized cooling has been recommended to standardize the physiological cold stress applied across participants, but critical experimental details remain unclear. The purpose of this work was to develop a detailed methodology for an individualized, perception-based protocol to investigate human physiological responses to cooling. Participants were wrapped in two water-circulating blankets and fitted with skin temperature probes to estimate BAT activity and peripheral vasoconstriction. We created a thermoesthesia graphical user interface (tGUI) to continuously record the subject's perception of cooling and shivering status during the cooling protocol. The protocol began with a 15 min thermoneutral phase followed by a series of 10 min cooling phases and concluded when sustained shivering (>1 min duration) occurred. Researchers used perception of cooling feedback (tGUI ratings) to manually adjust and personalize the water temperature at each cooling phase. Blanket water temperatures were recorded continuously during the protocol. Twelve volunteers (ages: 26.2 ± 1.4 years; 25% female) completed a feasibility study to evaluate the proposed protocol. Water temperature, perception of cooling, and shivering varied considerably across participants in response to cooling. Mean clavicle skin temperature, a surrogate measure of BAT activity, decreased (-0.99°C, 95% CI: -1.7 to -0.25°C, = 0.16) after the cooling protocol, but an increase in supraclavicular skin temperature was observed in 4 participants. A strong positive correlation was also found between thermoesthesia and peripheral vasoconstriction (ρ = 0.84, < 0.001). The proposed individualized, perception-based protocol therefore has potential to investigate the physiological responses to cold stress applied across populations with varying age, sex, body composition, and cold sensitivity characteristics.