Christopher M. Collins
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View article: First‐Order Spatial Encoding Simulations for Improved Accuracy in the Presence of Strong <scp> <i>B</i> <sub>0</sub> </scp> and Gradient Field Variations
First‐Order Spatial Encoding Simulations for Improved Accuracy in the Presence of Strong <span> <i>B</i> <sub>0</sub> </span> and Gradient Field Variations Open
Purpose Low‐cost and application‐specific scanners with unconventional designs can entail substantial inhomogeneities of the main magnetic field and non‐linearities of the gradient fields, which challenge assumptions made in MRI simulators…
View article: Dynamic fabrication method of SNAP microresonators
Dynamic fabrication method of SNAP microresonators Open
Surface Nanoscale Axial Photonics (SNAP) technology has demonstrated the record subangstrom fabrication precision of optical microresonators and resonant photonic circuits at the optical fiber surface. However, fabrication errors arising f…
View article: Power Scaling Methods for RF Excitation Fields in MRI Systems
Power Scaling Methods for RF Excitation Fields in MRI Systems Open
In this paper, we analyze the homogeneity of the transmitted radiofrequency (RF) field by applying different power scaling methods ranging from low-field (12.8 MHz, 0.3 T) to high-field (298 MHz, 7.0 T) magnetic resonance imaging (MRI) sys…
View article: SAR Image Reconstruction of RF Field Based on MR Temperature Image
SAR Image Reconstruction of RF Field Based on MR Temperature Image Open
View article: Preliminary Experience with Three Alternative Motion Sensors for 0.55 Tesla MR Imaging
Preliminary Experience with Three Alternative Motion Sensors for 0.55 Tesla MR Imaging Open
Due to limitations in current motion tracking technologies and increasing interest in alternative sensors for motion tracking both inside and outside the MRI system, in this study we share our preliminary experience with three alternative …
View article: CLINICAL IMPLEMENTATION OF PREEMPTIVE PHARMACOGENOMICS TESTING FOR PERSONALIZED MEDICINE AT AN ACADEMIC MEDICAL CENTER
CLINICAL IMPLEMENTATION OF PREEMPTIVE PHARMACOGENOMICS TESTING FOR PERSONALIZED MEDICINE AT AN ACADEMIC MEDICAL CENTER Open
Objective This paper describes the implementation of preemptive clinical pharmacogenomics (PGx) testing linked to an automated electronic clinical decision support (CDS) system delivering clinically actionable PGx information to clinicians…
View article: Three-row MRI receive array with remote circuitry to preserve radiation transparency
Three-row MRI receive array with remote circuitry to preserve radiation transparency Open
Objective. Up to this point, 1.5 T linac-compatible coil array layouts have been restricted to one or two rows of coils because of the desire to place radiation-opaque circuitry adjacent to the coils and outside the window through which th…
View article: Quantitative proteomics of pancreatic cyst fluid for early diagnosis of cancer.
Quantitative proteomics of pancreatic cyst fluid for early diagnosis of cancer. Open
View article: AB151. SOH23ABS_207. Needle in a haystack
AB151. SOH23ABS_207. Needle in a haystack Open
Background: A 46-year-old lady of Japanese ethnicity with a family history of gastric adenocarcinoma was referred with reflux symptoms. Diagnostic and staging investigations were contradicting on multiple biopsies for malignancy which prom…
View article: Evaluating Classroom Potential for Card-it: Digital Flashcards for Studying and Learning Italian Morphology
Evaluating Classroom Potential for Card-it: Digital Flashcards for Studying and Learning Italian Morphology Open
This paper presents Card-it, a web-based application for learning Italian verb conjugation. Card-it integrates a large-scale finite-state morphological~(FSM) analyzer and a flashcard application as a user-friendly way for learners to utili…
View article: Type I Interferon Signaling Controls Gammaherpesvirus Latency In Vivo
Type I Interferon Signaling Controls Gammaherpesvirus Latency In Vivo Open
Gammaherpesviruses, such as Epstein-Barr virus and Kaposi’s sarcoma-associated herpesvirus, are important human pathogens involved in lymphoproliferative disorders and tumorigenesis. Herpesvirus infections are characterized by a biphasic c…
View article: Neuronal activity under transcranial radio-frequency stimulation in metal-free rodent brains in-vivo
Neuronal activity under transcranial radio-frequency stimulation in metal-free rodent brains in-vivo Open
As the use of Radio Frequency (RF) technologies increases, the impact of RF radiation on neurological function continues to receive attention. Whether RF radiation can modulate ongoing neuronal activity by non-thermal mechanisms has been d…
View article: A Hybrid Volume-Surface Integral Equation Method for Rapid Electromagnetic Simulations in MRI
A Hybrid Volume-Surface Integral Equation Method for Rapid Electromagnetic Simulations in MRI Open
The efficiency of the novel hybrid-VSIE method could enable rapid simulations of complex and comprehensive MRI setups.
View article: High-permittivity pads to enhance SNR and transmit efficiency in MRI of the heart at 7T: a simulation study
High-permittivity pads to enhance SNR and transmit efficiency in MRI of the heart at 7T: a simulation study Open
View article: Improved whole‐brain SNR with an integrated high‐permittivity material in a head array at 7T
Improved whole‐brain SNR with an integrated high‐permittivity material in a head array at 7T Open
Purpose To demonstrate that strategic use of materials with high electric permittivity along with integrated head‐sized coil arrays can improve SNR in the entire brain. Methods Numerical simulations were used to design a high‐permittivity …
View article: Temperature‐based MRI safety simulations with a limited number of tissues
Temperature‐based MRI safety simulations with a limited number of tissues Open
Purpose Demonstrate ability to produce reasonable simulations of temperature using numerical models of the human body with a limited number of tissues. Methods For both a male and female human body model, numerical simulations were used to…
View article: <scp>7T MR</scp> Safety
<span>7T MR</span> Safety Open
Magnetic resonance imaging and spectroscopy (MRI/MRS) at 7T represents an exciting advance in MR technology, with intriguing possibilities to enhance image spatial, spectral, and contrast resolution. To ensure the safe use of this technolo…
View article: Murine gammaherpesvirus infection is skewed toward Igλ+ B cells expressing a specific heavy chain V-segment
Murine gammaherpesvirus infection is skewed toward Igλ+ B cells expressing a specific heavy chain V-segment Open
One of the defining characteristics of the B cell receptor (BCR) is the extensive diversity in the repertoire of immunoglobulin genes that make up the BCR, resulting in broad range of specificity. Gammaherpesviruses are B lymphotropic viru…
View article: Improvement of SNR in MRgFUS with strategic design of bath medium and transducer ground plane
Improvement of SNR in MRgFUS with strategic design of bath medium and transducer ground plane Open
MR-guided Focused Ultrasound (MRgFUS) of the head at 3 Tesla suffers from low image Signal-to-Noise ration in exactly the region of interest in the brain due to severe dielectric effects from the water bolus surrounding the head to facilit…
View article: Improved brain imaging with a head array with integrated high-permittivity material
Improved brain imaging with a head array with integrated high-permittivity material Open
High electric permittivity materials (HPM) have been used to improve transmit efficiency and receive sensitivity in targeted regions. In this work we demonstrate improvements in the entire b rain by designing and implementing an integrated…
View article: A 3D printed patient-specific dual compartment breast phantom for validating MRI acquisition and analysis techniques
A 3D printed patient-specific dual compartment breast phantom for validating MRI acquisition and analysis techniques Open
Anthropomorphic phantoms are essential tools that are used to validate MRI acquisition and analysis techniques. 3D printing technologies are rapidly advancing and can be utilized to achieve anatomically realistic geometries that are not at…
View article: Optimization of the order and spacing of sequences in an MRI exam to reduce the maximum temperature and thermal dose
Optimization of the order and spacing of sequences in an MRI exam to reduce the maximum temperature and thermal dose Open
Purpose Evaluate the possibility to reduce specific energy absorption rate (SAR)‐induced maximum temperature and thermal dose by rearranging the order and spacing of sequences without increasing duration of the MRI examination. Methods Usi…
View article: The Optimality Principle for MR signal excitation and reception: New physical insights into ideal radiofrequency coil design
The Optimality Principle for MR signal excitation and reception: New physical insights into ideal radiofrequency coil design Open
Purpose: Despite decades of collective experience, radiofrequency coil optimization for MR has remained a largely empirical process, with clear insight into what might constitute truly task-optimal, as opposed to merely 'good,' coil perfor…
View article: Transverse slot antennas for high field MRI
Transverse slot antennas for high field MRI Open
Purpose Introduce a novel coil design using an electrically long transversely oriented slot in a conductive sheet. Theory and Methods Theoretical considerations, numerical simulations, and experimental measurements are presented for transv…
View article: Improved detection of fMRI activation in the cerebellum at 7T with dielectric pads extending the imaging region of a commercial head coil
Improved detection of fMRI activation in the cerebellum at 7T with dielectric pads extending the imaging region of a commercial head coil Open
Background There is growing interest in detecting cerebro‐cerebellar circuits, which requires adequate blood oxygenation level dependent contrast and signal‐to‐noise ratio (SNR) throughout the brain. Although 7T scanners offer increased SN…
View article: Consequences of a changing US strategy in the global HIV investment landscape
Consequences of a changing US strategy in the global HIV investment landscape Open
Our synthesis of available evidence shows that the United States has played, and could continue to play, a vital role in the global HIV response. Reduced investment could allow more than two million avoidable AIDS deaths by 2032, whereas c…
View article: Predation on invasive snails, the Red-rimmed Melania (Melanoides tuberculata) and the Giant Ramshorn Snail (Marisa cornuarietis), by the Eastern Musk Turtle (Sternotherus odoratus) in a Texas spring
Predation on invasive snails, the Red-rimmed Melania (Melanoides tuberculata) and the Giant Ramshorn Snail (Marisa cornuarietis), by the Eastern Musk Turtle (Sternotherus odoratus) in a Texas spring Open
View article: A method to assess the loss of a dipole antenna for ultra‐high‐field MRI
A method to assess the loss of a dipole antenna for ultra‐high‐field MRI Open
Purpose To describe a new bench measurement based on quality ( Q ) factors to estimate the coil noise relative to the sample noise of dipole antennas at 7 T. Methods Placing a dipole antenna close to a highly conductive sample surrogate (H…
View article: Parallel transmission RF pulse design with strict temperature constraints
Parallel transmission RF pulse design with strict temperature constraints Open
RF safety in parallel transmission (pTx) is generally ensured by imposing specific absorption rate (SAR) limits during pTx RF pulse design. There is increasing interest in using temperature to ensure safety in MRI. In this work, we present…
View article: On the potential for <scp>RF</scp> heating in <scp>MRI</scp> to affect metabolic rates and <sup>18</sup><scp>FDG</scp> signal in <scp>PET</scp>/<scp>MR</scp>: simulations of long‐duration, maximum normal mode heating
On the potential for <span>RF</span> heating in <span>MRI</span> to affect metabolic rates and <sup>18</sup><span>FDG</span> signal in <span>PET</span>/<span>MR</span>: simulations of long‐duration, maximum normal mode heating Open
Purpose To examine the possibility that MR ‐induced RF power deposition ( SAR ) and the resulting effects on temperature‐dependent metabolic rates or perfusion rates might affect observed 18 FDG signal in PET / MR . Methods Using numerical…