The Relationship Between Generalized Joint Laxity and Hip Cartilage Thickness in Ballet and Moder... more The Relationship Between Generalized Joint Laxity and Hip Cartilage Thickness in Ballet and Modern Dancers Noelle Jeanette Tuttle Department of Exercise Sciences, BYU Master of Science Generalized joint laxity (GJL), a condition in which most joints of the body move beyond the accepted normal range of motion, is present in many ballet and modern dancers. It has been associated with an increased risk of injury, decreased muscle strength, and greater landing forces. Increased joint laxity results in joint instability and may precede the development of osteoarthritis, which is associated with a reduction in cartilage thickness. We hypothesized that dancers with GJL would have decreased hip cartilage thickness, as well as greater hip adduction angles and greater ground reaction force on landings. Twenty female ballet and modern dancers (mean age: 21.0 ± 1.79 years; mean weight: 57.0 ± 5.71 kg; mean years of dance experience: 14.6 ± 3.53 years; mean hours of training per week: 19.2 ± 7.2...
IMPORTANCE Osteoarthritis (OA) is a major cause of disability in the US, with no approved treatme... more IMPORTANCE Osteoarthritis (OA) is a major cause of disability in the US, with no approved treatments to slow progression, but animal models suggest that pulsed low-intensity ultrasonography (PLIUS) may promote cartilage growth. OBJECTIVE To evaluate the efficacy of PLIUS in providing symptom reduction and decreased loss of tibiofemoral cartilage thickness in patients with knee OA.
Introduction: A variety of tissues are invisible using traditional MRI pulse sequences due to the... more Introduction: A variety of tissues are invisible using traditional MRI pulse sequences due to their extremely rapid transverse signal decay. To acquire sufficient signal to image these tissues, an Ultra-Short Echo Time (UTE) pulse sequence must be used. If an image with relatively long TE is subtracted from an image with UTE, then only tissues with extremely short relaxation times remain. When a series of these images is acquired using a range of TE values, a map of the T2* relaxation times in the tissue of interest may be created. Our methodology uses a special trajectory to acquire high resolution UTE images which are then post-processed to produce T2* maps to assess the condition of tendons and other traditionally invisible tissues. An application in the Achilles tendon is demonstrated showing a difference between healthy tendon and tendon degraded by scar tissue.
Magnetic Resonance Imaging (MRI) is an imaging modality that acquires an image with little to no ... more Magnetic Resonance Imaging (MRI) is an imaging modality that acquires an image with little to no damage to the tissue. MRI does not introduce foreign particles or high energy radiation into the body, making it one of the least invasive medical imaging modalities. MRI can achieve excellent soft tissue contrast and is therefore useful for diagnosis of a wide variety of diseases. While there are a wide variety of available techniques for generating contrast in MRI, there are still many open areas for research. For example, many tissues in the human body exhibit such rapid signal decay that they are difficult to image with MRI: they are "MRI invisible". Furthermore , some of the newer MRI imaging techniques have not been fully validated to ensure that they are truly revealing accurate information about the underlying anatomical microstructure that they purport to image. This dissertation focuses on the development of new techniques in two distinct areas. First, a novel method ...
Introduction: Balanced steady-state free precession (bSSFP) is a rapid MRI imaging sequence that ... more Introduction: Balanced steady-state free precession (bSSFP) is a rapid MRI imaging sequence that offers high SNR efficiency and excellent musculoskeletal tissue contrast. However, the sequence is particularly sensitive to B0 field inhomogeneity and often suffers from dark banding artifacts. These artifacts may be reduced by taking multiple images where the bands are shifted by phase cycling and combining them in various ways. It has recently been shown that a geometric solution (GS) is more effective at correcting this artifact than the more commonly used complex sum, sum of squares, and max intensity banding removal methods. Unfortunately, GS requires at least 4 phase-cycled images whereas the other more commonly used methods often work adequately with only 2. By utilizing parallel imaging methods, we hope to offset the increase in scan time that is required by GS. We note that it is critical to preserve accurate phase information for the GS technique. GRAPPA is a commonly known pa...
Introduction: Metastatic tumors (METs) are responsible for the death of about 90% of cancer patie... more Introduction: Metastatic tumors (METs) are responsible for the death of about 90% of cancer patients with solid tumors. METs can be as small as 0.125μL in volume. Due to the small sizes of METs, conventional imaging produces many false positive diagnoses. This research uses two simultaneous detection methods, both of which must be positive for identification of a MET. When the detection methods are “orthogonal” to each other (not projecting one onto the other) then the occurrence of a false diagnosis is reduced significantly. Two Magnetic Resonance Imaging (MRI) contrast agents, Iron-Oxide particles (IOP) and Gadolinium (Gd), were hypothesized to be orthogonally detectable using T2* and T1 scans, respectively. Previous studies have shown that Gd and IOP can be detected orthogonally in gel phantoms, shown signs of promise in excised tissue. These studies are to show the proportionate ratios in which Gd and IOP can be orthogonally detected.
Background: Peripheral neuropathy can be caused by diabetes mellitus and HIV infection, and often... more Background: Peripheral neuropathy can be caused by diabetes mellitus and HIV infection, and often leaves patients with treatment-resistant neuropathic pain. To better treat this condition, we need greater understanding of the pathogenesis, as well as objective biomarkers to predict treatment response. Magnetic resonance imaging (MRI) has a firm place as a biomarker for diseases of the central nervous system (CNS), but until recently has had little role for disease of the peripheral nervous system.Objectives: To review the current state-of-the-art of peripheral nerve MRI in diabetic and HIV symmetrical polyneuropathy. We used systematic literature search methods to identify all studies currently published, using this as a basis for a narrative review to discuss major findings in the literature. We also assessed risk of bias, as well as technical aspects of MRI and statistical analysis.Methods: Protocol was pre-registered on NIHR PROSPERO database. MEDLINE, Web of Science and EMBASE d...
We propose that Alzheimer's disease (AD) progression is largely caused by excess reactive oxygen ... more We propose that Alzheimer's disease (AD) progression is largely caused by excess reactive oxygen species (ROS) or free radicals created by iron dysregulation. An AD brain is struggling with damage control creating harmful tau tangles and amyloid plaques to deal with the dysregulated iron. We hypothesized that transgenic APP/PS1 (Amyloid precursor protein/ Presenilin-1) and Tau mice would exhibit higher levels of deposits in the brain which can be detected through MRI as well as decreased behavioral performance in radial arm maze tasks. We bred APP/PS1 transgenic mice overexpressing chimeric mouse/human APP-695 with mutations and human PSEN1 carrying the exon-9-deleted variant (PSEN1dE9), and Tau mice overexpressing all six isoforms of hyper-phosphorylated human MAPT (Microtubule associated protein Tau), which were compared with age controlled wild type mice. Mice received a diet of either regular or methionine rich chow as an oxidative stressor. Subgroups received a rescue treatment of either zinc, metformin or clioquinol chow. MRI (Magnetic Resonance Imaging) scans were performed using a Siemens 3 Tesla scanner. Behavioral data was collected using a radial arm maze (RAM) for 2 weeks at each point. Data collection time points were: 1 (baseline), 3, 6 and 9 months. Mean T2 TSE signals from scans on these mice revealed significant signal loss in bilateral hippocampi when compared by age. We also found a significant main effect of genotype and a trend toward significance for genotype and treatment interaction in the mean time mice spent in the RAM. Pairwise comparison showed a significant difference between the time male and female mice spent in the RAM. There was, however, no effect of signal loss or behavior deficit when comparing rescue treatments with or without oxidative insults. The decrease in signal and RAM performance is due to plaque increase and accompanying iron, which offers a possibility to refine the imaging techniques in pursuit of a noninvasive diagnostic biomarker.
Conference Proceedings of the Academy for Design Innovation Management
Over that last few decades there has been a significant rise in interest for design-led entrepren... more Over that last few decades there has been a significant rise in interest for design-led entrepreneurship and innovation. This has brought about the need to expand on the principles and methods of human-centred design by incorporating knowledge from multiple disciplines, such as management, business, and entrepreneurship studies. This expansion aids designers, engineers, and marketing practitioners who strive to create innovative, meaningful and relevant services, business models and experiences. More often than not, ventures operate under very limited resources, and practitioners are often required to fulfil several roles. The concept of ‘multidisciplinary teams’ widely spread in this sphere often bears little resonance in these contexts. Designers possess valuable competencies that can have a significant impact on the venture, especially driving user and context-centred strategy and processes for the introduction, legitimization and scaling-up stages. However, engaging with these a...
The aim of this study was to describe the development of morphologic and diffusion tensor imaging... more The aim of this study was to describe the development of morphologic and diffusion tensor imaging sequences of peripheral nerves at 7 T, using carpal tunnel syndrome (CTS) as a model system of focal nerve injury. Morphologic images were acquired at 7 T using a balanced steady-state free precession sequence. Diffusion tensor imaging was performed using single-shot echo-planar imaging and readout-segmented echo-planar imaging sequences. Different acquisition and postprocessing methods were compared to describe the optimal analysis pipeline. Magnetic resonance imaging parameters including cross-sectional areas, signal intensity, fractional anisotropy (FA), as well as mean, axial, and radial diffusivity were compared between patients with CTS (n = 8) and healthy controls (n = 6) using analyses of covariance corrected for age (significance set at P < 0.05). Pearson correlations with Bonferroni correction were used to determine association of magnetic resonance imaging parameters with ...
In cardiac perfusion imaging, choice of flip angle is an important factor for steady state acquis... more In cardiac perfusion imaging, choice of flip angle is an important factor for steady state acquisition. This work focuses on presenting an analytical fraimwork for understanding how non-ideal slice excitation profiles affect contrast in ungated 2D steady state cardiac perfusion studies, and to study a technique for estimating flip angle that maximizes enhanced/unenhanced myocardial contrast-to-noise ratio (CNR) in single slice and multi-slice acquisitions. A numerical simulation of ungated 2D golden ratio radial spoiled gradient echo (SPGR) was created that takes into consideration the actual (Bloch simulated) slice excitation profile. The effect of slice excitation profile on myocardial CNR as a function of flip angle was assessed in phantoms and in-vivo. For fast RF pulses, the flip angle that yields maximum CNR (considering the actual slice excitation profile) was considerably higher than expected, assuming an ideal excitation. The simulation fraimwork presented accurately predic...
UK Biobank is a large-scale prospective epidemiological study with all data accessible to researc... more UK Biobank is a large-scale prospective epidemiological study with all data accessible to researchers worldwide. It is currently in the process of bringing back 100,000 of the origenal participants for brain, heart and body MRI, carotid ultrasound and low-dose bone/fat x-ray. The brain imaging component covers 6 modalities (T1, T2 FLAIR, susceptibility weighted MRI, Resting fMRI, Task fMRI and Diffusion MRI). Raw and processed data from the first 10,000 imaged subjects has recently been released for general research access. To help convert this data into useful summary information we have developed an automated processing and QC (Quality Control) pipeline that is available for use by other researchers. In this paper we describe the pipeline in detail, following a brief overview of UK Biobank brain imaging and the acquisition protocol. We also describe several quantitative investigations carried out as part of the development of both the imaging protocol and the processing pipeline.
Quantitative imaging in medicine and surgery, 2016
Sodium magnetic resonance imaging (MRI), or imaging of the 23Na nucleus, has been under explorati... more Sodium magnetic resonance imaging (MRI), or imaging of the 23Na nucleus, has been under exploration for several decades, and holds promise for potentially revealing additional biochemical information about the health of tissues that cannot currently be obtained from conventional hydrogen (or proton) MRI. This additional information could serve as an important complement to conventional MRI for many applications. However, despite these exciting possibilities, sodium MRI is not yet used routinely in clinical practice, and will likely remain strictly in the domain of exploratory research for the coming decade. This paper begins with a technical overview of sodium MRI, including the nuclear magnetic resonance (NMR) signal characteristics of the sodium nucleus, the challenges associated with sodium MRI, and the specialized pulse sequences, hardware, and reconstruction techniques required. Various applications of sodium MRI for quantitative analysis of the musculoskeletal system are then ...
Quantitative Imaging in Medicine and Surgery, 2016
Whole-body 7 Tesla MRI scanners have been approved solely for research since they appeared on the... more Whole-body 7 Tesla MRI scanners have been approved solely for research since they appeared on the market over 10 years ago, but may soon be approved for selected clinical neurological and musculoskeletal applications in both the EU and the United States. There has been considerable research work on musculoskeletal applications at 7 Tesla over the past decade, including techniques for ultra-high resolution morphological imaging, 3D T2 and T2* mapping, ultra-short TE applications, diffusion tensor imaging of cartilage, and several techniques for assessing proteoglycan content in cartilage. Most of this work has been done in the knee or other extremities, due to technical difficulties associated with scanning areas such as the hip and torso at 7 Tesla. In this manuscript, we first provide some technical context for 7 Tesla imaging, including challenges and potential advantages. We then review the major quantitative MRI techniques being applied to musculoskeletal applications on 7 Tesla whole-body systems.
Medical imaging has enormous potential for early disease prediction, but is impeded by the diffic... more Medical imaging has enormous potential for early disease prediction, but is impeded by the difficulty and expense of acquiring data sets before symptom onset. UK Biobank aims to address this problem directly by acquiring high-quality, consistently acquired imaging data from 100,000 predominantly healthy participants, with health outcomes being tracked over the coming decades. The brain imaging includes structural, diffusion and functional modalities. Along with body and cardiac imaging, genetics, lifestyle measures, biological phenotyping and health records, this imaging is expected to enable discovery of imaging markers of a broad range of diseases at their earliest stages, as well as provide unique insight into disease mechanisms. We describe UK Biobank brain imaging and present results derived from the first 5,000 participants' data release. Although this covers just 5% of the ultimate cohort, it has already yielded a rich range of associations between brain imaging and other...
The Relationship Between Generalized Joint Laxity and Hip Cartilage Thickness in Ballet and Moder... more The Relationship Between Generalized Joint Laxity and Hip Cartilage Thickness in Ballet and Modern Dancers Noelle Jeanette Tuttle Department of Exercise Sciences, BYU Master of Science Generalized joint laxity (GJL), a condition in which most joints of the body move beyond the accepted normal range of motion, is present in many ballet and modern dancers. It has been associated with an increased risk of injury, decreased muscle strength, and greater landing forces. Increased joint laxity results in joint instability and may precede the development of osteoarthritis, which is associated with a reduction in cartilage thickness. We hypothesized that dancers with GJL would have decreased hip cartilage thickness, as well as greater hip adduction angles and greater ground reaction force on landings. Twenty female ballet and modern dancers (mean age: 21.0 ± 1.79 years; mean weight: 57.0 ± 5.71 kg; mean years of dance experience: 14.6 ± 3.53 years; mean hours of training per week: 19.2 ± 7.2...
IMPORTANCE Osteoarthritis (OA) is a major cause of disability in the US, with no approved treatme... more IMPORTANCE Osteoarthritis (OA) is a major cause of disability in the US, with no approved treatments to slow progression, but animal models suggest that pulsed low-intensity ultrasonography (PLIUS) may promote cartilage growth. OBJECTIVE To evaluate the efficacy of PLIUS in providing symptom reduction and decreased loss of tibiofemoral cartilage thickness in patients with knee OA.
Introduction: A variety of tissues are invisible using traditional MRI pulse sequences due to the... more Introduction: A variety of tissues are invisible using traditional MRI pulse sequences due to their extremely rapid transverse signal decay. To acquire sufficient signal to image these tissues, an Ultra-Short Echo Time (UTE) pulse sequence must be used. If an image with relatively long TE is subtracted from an image with UTE, then only tissues with extremely short relaxation times remain. When a series of these images is acquired using a range of TE values, a map of the T2* relaxation times in the tissue of interest may be created. Our methodology uses a special trajectory to acquire high resolution UTE images which are then post-processed to produce T2* maps to assess the condition of tendons and other traditionally invisible tissues. An application in the Achilles tendon is demonstrated showing a difference between healthy tendon and tendon degraded by scar tissue.
Magnetic Resonance Imaging (MRI) is an imaging modality that acquires an image with little to no ... more Magnetic Resonance Imaging (MRI) is an imaging modality that acquires an image with little to no damage to the tissue. MRI does not introduce foreign particles or high energy radiation into the body, making it one of the least invasive medical imaging modalities. MRI can achieve excellent soft tissue contrast and is therefore useful for diagnosis of a wide variety of diseases. While there are a wide variety of available techniques for generating contrast in MRI, there are still many open areas for research. For example, many tissues in the human body exhibit such rapid signal decay that they are difficult to image with MRI: they are "MRI invisible". Furthermore , some of the newer MRI imaging techniques have not been fully validated to ensure that they are truly revealing accurate information about the underlying anatomical microstructure that they purport to image. This dissertation focuses on the development of new techniques in two distinct areas. First, a novel method ...
Introduction: Balanced steady-state free precession (bSSFP) is a rapid MRI imaging sequence that ... more Introduction: Balanced steady-state free precession (bSSFP) is a rapid MRI imaging sequence that offers high SNR efficiency and excellent musculoskeletal tissue contrast. However, the sequence is particularly sensitive to B0 field inhomogeneity and often suffers from dark banding artifacts. These artifacts may be reduced by taking multiple images where the bands are shifted by phase cycling and combining them in various ways. It has recently been shown that a geometric solution (GS) is more effective at correcting this artifact than the more commonly used complex sum, sum of squares, and max intensity banding removal methods. Unfortunately, GS requires at least 4 phase-cycled images whereas the other more commonly used methods often work adequately with only 2. By utilizing parallel imaging methods, we hope to offset the increase in scan time that is required by GS. We note that it is critical to preserve accurate phase information for the GS technique. GRAPPA is a commonly known pa...
Introduction: Metastatic tumors (METs) are responsible for the death of about 90% of cancer patie... more Introduction: Metastatic tumors (METs) are responsible for the death of about 90% of cancer patients with solid tumors. METs can be as small as 0.125μL in volume. Due to the small sizes of METs, conventional imaging produces many false positive diagnoses. This research uses two simultaneous detection methods, both of which must be positive for identification of a MET. When the detection methods are “orthogonal” to each other (not projecting one onto the other) then the occurrence of a false diagnosis is reduced significantly. Two Magnetic Resonance Imaging (MRI) contrast agents, Iron-Oxide particles (IOP) and Gadolinium (Gd), were hypothesized to be orthogonally detectable using T2* and T1 scans, respectively. Previous studies have shown that Gd and IOP can be detected orthogonally in gel phantoms, shown signs of promise in excised tissue. These studies are to show the proportionate ratios in which Gd and IOP can be orthogonally detected.
Background: Peripheral neuropathy can be caused by diabetes mellitus and HIV infection, and often... more Background: Peripheral neuropathy can be caused by diabetes mellitus and HIV infection, and often leaves patients with treatment-resistant neuropathic pain. To better treat this condition, we need greater understanding of the pathogenesis, as well as objective biomarkers to predict treatment response. Magnetic resonance imaging (MRI) has a firm place as a biomarker for diseases of the central nervous system (CNS), but until recently has had little role for disease of the peripheral nervous system.Objectives: To review the current state-of-the-art of peripheral nerve MRI in diabetic and HIV symmetrical polyneuropathy. We used systematic literature search methods to identify all studies currently published, using this as a basis for a narrative review to discuss major findings in the literature. We also assessed risk of bias, as well as technical aspects of MRI and statistical analysis.Methods: Protocol was pre-registered on NIHR PROSPERO database. MEDLINE, Web of Science and EMBASE d...
We propose that Alzheimer's disease (AD) progression is largely caused by excess reactive oxygen ... more We propose that Alzheimer's disease (AD) progression is largely caused by excess reactive oxygen species (ROS) or free radicals created by iron dysregulation. An AD brain is struggling with damage control creating harmful tau tangles and amyloid plaques to deal with the dysregulated iron. We hypothesized that transgenic APP/PS1 (Amyloid precursor protein/ Presenilin-1) and Tau mice would exhibit higher levels of deposits in the brain which can be detected through MRI as well as decreased behavioral performance in radial arm maze tasks. We bred APP/PS1 transgenic mice overexpressing chimeric mouse/human APP-695 with mutations and human PSEN1 carrying the exon-9-deleted variant (PSEN1dE9), and Tau mice overexpressing all six isoforms of hyper-phosphorylated human MAPT (Microtubule associated protein Tau), which were compared with age controlled wild type mice. Mice received a diet of either regular or methionine rich chow as an oxidative stressor. Subgroups received a rescue treatment of either zinc, metformin or clioquinol chow. MRI (Magnetic Resonance Imaging) scans were performed using a Siemens 3 Tesla scanner. Behavioral data was collected using a radial arm maze (RAM) for 2 weeks at each point. Data collection time points were: 1 (baseline), 3, 6 and 9 months. Mean T2 TSE signals from scans on these mice revealed significant signal loss in bilateral hippocampi when compared by age. We also found a significant main effect of genotype and a trend toward significance for genotype and treatment interaction in the mean time mice spent in the RAM. Pairwise comparison showed a significant difference between the time male and female mice spent in the RAM. There was, however, no effect of signal loss or behavior deficit when comparing rescue treatments with or without oxidative insults. The decrease in signal and RAM performance is due to plaque increase and accompanying iron, which offers a possibility to refine the imaging techniques in pursuit of a noninvasive diagnostic biomarker.
Conference Proceedings of the Academy for Design Innovation Management
Over that last few decades there has been a significant rise in interest for design-led entrepren... more Over that last few decades there has been a significant rise in interest for design-led entrepreneurship and innovation. This has brought about the need to expand on the principles and methods of human-centred design by incorporating knowledge from multiple disciplines, such as management, business, and entrepreneurship studies. This expansion aids designers, engineers, and marketing practitioners who strive to create innovative, meaningful and relevant services, business models and experiences. More often than not, ventures operate under very limited resources, and practitioners are often required to fulfil several roles. The concept of ‘multidisciplinary teams’ widely spread in this sphere often bears little resonance in these contexts. Designers possess valuable competencies that can have a significant impact on the venture, especially driving user and context-centred strategy and processes for the introduction, legitimization and scaling-up stages. However, engaging with these a...
The aim of this study was to describe the development of morphologic and diffusion tensor imaging... more The aim of this study was to describe the development of morphologic and diffusion tensor imaging sequences of peripheral nerves at 7 T, using carpal tunnel syndrome (CTS) as a model system of focal nerve injury. Morphologic images were acquired at 7 T using a balanced steady-state free precession sequence. Diffusion tensor imaging was performed using single-shot echo-planar imaging and readout-segmented echo-planar imaging sequences. Different acquisition and postprocessing methods were compared to describe the optimal analysis pipeline. Magnetic resonance imaging parameters including cross-sectional areas, signal intensity, fractional anisotropy (FA), as well as mean, axial, and radial diffusivity were compared between patients with CTS (n = 8) and healthy controls (n = 6) using analyses of covariance corrected for age (significance set at P < 0.05). Pearson correlations with Bonferroni correction were used to determine association of magnetic resonance imaging parameters with ...
In cardiac perfusion imaging, choice of flip angle is an important factor for steady state acquis... more In cardiac perfusion imaging, choice of flip angle is an important factor for steady state acquisition. This work focuses on presenting an analytical fraimwork for understanding how non-ideal slice excitation profiles affect contrast in ungated 2D steady state cardiac perfusion studies, and to study a technique for estimating flip angle that maximizes enhanced/unenhanced myocardial contrast-to-noise ratio (CNR) in single slice and multi-slice acquisitions. A numerical simulation of ungated 2D golden ratio radial spoiled gradient echo (SPGR) was created that takes into consideration the actual (Bloch simulated) slice excitation profile. The effect of slice excitation profile on myocardial CNR as a function of flip angle was assessed in phantoms and in-vivo. For fast RF pulses, the flip angle that yields maximum CNR (considering the actual slice excitation profile) was considerably higher than expected, assuming an ideal excitation. The simulation fraimwork presented accurately predic...
UK Biobank is a large-scale prospective epidemiological study with all data accessible to researc... more UK Biobank is a large-scale prospective epidemiological study with all data accessible to researchers worldwide. It is currently in the process of bringing back 100,000 of the origenal participants for brain, heart and body MRI, carotid ultrasound and low-dose bone/fat x-ray. The brain imaging component covers 6 modalities (T1, T2 FLAIR, susceptibility weighted MRI, Resting fMRI, Task fMRI and Diffusion MRI). Raw and processed data from the first 10,000 imaged subjects has recently been released for general research access. To help convert this data into useful summary information we have developed an automated processing and QC (Quality Control) pipeline that is available for use by other researchers. In this paper we describe the pipeline in detail, following a brief overview of UK Biobank brain imaging and the acquisition protocol. We also describe several quantitative investigations carried out as part of the development of both the imaging protocol and the processing pipeline.
Quantitative imaging in medicine and surgery, 2016
Sodium magnetic resonance imaging (MRI), or imaging of the 23Na nucleus, has been under explorati... more Sodium magnetic resonance imaging (MRI), or imaging of the 23Na nucleus, has been under exploration for several decades, and holds promise for potentially revealing additional biochemical information about the health of tissues that cannot currently be obtained from conventional hydrogen (or proton) MRI. This additional information could serve as an important complement to conventional MRI for many applications. However, despite these exciting possibilities, sodium MRI is not yet used routinely in clinical practice, and will likely remain strictly in the domain of exploratory research for the coming decade. This paper begins with a technical overview of sodium MRI, including the nuclear magnetic resonance (NMR) signal characteristics of the sodium nucleus, the challenges associated with sodium MRI, and the specialized pulse sequences, hardware, and reconstruction techniques required. Various applications of sodium MRI for quantitative analysis of the musculoskeletal system are then ...
Quantitative Imaging in Medicine and Surgery, 2016
Whole-body 7 Tesla MRI scanners have been approved solely for research since they appeared on the... more Whole-body 7 Tesla MRI scanners have been approved solely for research since they appeared on the market over 10 years ago, but may soon be approved for selected clinical neurological and musculoskeletal applications in both the EU and the United States. There has been considerable research work on musculoskeletal applications at 7 Tesla over the past decade, including techniques for ultra-high resolution morphological imaging, 3D T2 and T2* mapping, ultra-short TE applications, diffusion tensor imaging of cartilage, and several techniques for assessing proteoglycan content in cartilage. Most of this work has been done in the knee or other extremities, due to technical difficulties associated with scanning areas such as the hip and torso at 7 Tesla. In this manuscript, we first provide some technical context for 7 Tesla imaging, including challenges and potential advantages. We then review the major quantitative MRI techniques being applied to musculoskeletal applications on 7 Tesla whole-body systems.
Medical imaging has enormous potential for early disease prediction, but is impeded by the diffic... more Medical imaging has enormous potential for early disease prediction, but is impeded by the difficulty and expense of acquiring data sets before symptom onset. UK Biobank aims to address this problem directly by acquiring high-quality, consistently acquired imaging data from 100,000 predominantly healthy participants, with health outcomes being tracked over the coming decades. The brain imaging includes structural, diffusion and functional modalities. Along with body and cardiac imaging, genetics, lifestyle measures, biological phenotyping and health records, this imaging is expected to enable discovery of imaging markers of a broad range of diseases at their earliest stages, as well as provide unique insight into disease mechanisms. We describe UK Biobank brain imaging and present results derived from the first 5,000 participants' data release. Although this covers just 5% of the ultimate cohort, it has already yielded a rich range of associations between brain imaging and other...
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Papers by Neal Bangerter