Publications by authors named "E M Versteeg"
Background: Canada has the fourth highest per capita rate of opioid prescriptions in the world, contributing to the country's opioid crisis. Due to both their pain-relieving and euphoric properties, opioids can be highly addictive, leading to potential overdose and death. Deprescription is an endorsed and organized method of discontinuing a drug but very little is known about the barriers that Canadian physicians face when attempting to deprescribe opioids, particularly those who practice in rural areas (which have some of the highest rates of opioid users).
View Article and Find Full Text PDFArticle Synopsis
- A new 3D MR-STAT protocol was developed to address issues with cerebrospinal fluid (CSF) pulsation artifacts in brain imaging, which commonly affect image quality.
- The researchers optimized the sequence to reduce noise and CSF signal, validating its effectiveness using both phantoms and healthy volunteers, resulting in improved quantitative maps without CSF-related distortions.
- The final protocol demonstrates high-quality imaging with minimal variability across subjects, allowing for rapid and accurate whole-brain relaxometry scans in just 5.5 minutes.
Purpose: To demonstrate the feasibility of using a nonlinear gradient field for spatial encoding at the ultrasonic switching frequency of 20 kHz and present a framework to reconstruct data acquired in this way.
Methods: Nonlinear encoding at 20 kHz was realized by using a single-axis silent gradient insert for imaging in the periphery, that, is the nonlinear region, of the gradient field. The gradient insert induces a rapidly oscillating gradient field in the phase-encode direction, which enables nonlinear encoding when combined with a Cartesian readout from the linear whole-body gradients.
Purpose: To demonstrate the feasibility and robustness of the Magnetic Resonance Spin TomogrAphy in Time-domain (MR-STAT) framework for fast, high SNR relaxometry at 7T.
Methods: To deploy MR-STAT on 7T-systems, we designed optimized flip-angles using the BLAKJac-framework that incorporates the SAR-constraints. Transmit RF-inhomogeneities were mitigated by including a measured -map in the reconstruction.
Purpose: We present a novel silent echo-planar spectroscopic imaging (EPSI) readout, which uses an ultrasonic gradient insert to accelerate MRSI while producing a high spectral bandwidth (20 kHz) and a low sound level.
Methods: The ultrasonic gradient insert consisted of a single-axis (z-direction) plug-and-play gradient coil, powered by an audio amplifier, and produced 40 mT/m at 20 kHz. The silent EPSI readout was implemented in a phase-encoded MRSI acquisition.