11 results on '"Noseworthy, Michael D."'
Search Results
2. Characterizing blood oxygen level-dependent (BOLD) response following in-magnet quadriceps exercise
- Author
-
Caterini, Jessica E., Elzibak, Alyaa H., Michel, Emilie Jean St., McCrindle, Brian W., Redington, Andrew N., Thompson, Sara, Noseworthy, Michael D., and Wells, Greg D.
- Published
- 2015
- Full Text
- View/download PDF
3. Assessment of diffusion tensor imaging indices in calf muscles following postural change from standing to supine position
- Author
-
Elzibak, Alyaa H. and Noseworthy, Michael D.
- Published
- 2014
- Full Text
- View/download PDF
4. Potential Role of MRI Imaging for Myofascial Pain: A Scoping Review for the Clinicians and Theoretical Considerations.
- Author
-
Evans, Valerie, Behr, Michael, Gangwar, Anshika, Noseworthy, Michael D, and Kumbhare, Dinesh
- Subjects
MAGNETIC resonance imaging ,MEDICAL personnel ,MUSCULOSKELETAL pain ,ULTRASONIC imaging ,SKELETAL muscle ,MYOFASCIAL pain syndromes - Abstract
The most common cause of chronic musculoskeletal pain is chronic myofascial pain syndrome (MPS). MPS often presents with increased muscle stiffness, and the myofascial trigger point (MTrP). Imaging modalities have been used to identify the MTrP, but their role in the detection and diagnosis of MPS remains unclear. The purpose of this review was to identify evidence in literature for the use of imaging in the role of classifying and explaining the physiology of MTrPs. Since few imaging techniques have been performed on MTrPs, we explored the imaging techniques that can effectively image complex skeletal muscle microstructure, and how they could be used. As part of a scoping review, we conducted a systematic search from three medical databases (CINAHL, EMBASE and MEDLINE) from year to year to analyze past MTrP imaging, as well as analyzing imaging techniques performed on the microstructure of muscle. Previously, ultrasound has been used to differentiate active, latent MTrPs, but these studies do not adequately address their underlying anatomical structure. MRI remains the standard method of imaging skeletal muscle. The existing MRI literature suggests that the DTI technique can quantify muscle injury, strain, and structure. However, theoretically, HARDI and DKI techniques seem to provide more information for complex structural areas, although these modalities have a disadvantage of longer scan times and have not been widely used on skeletal muscle. Our review suggests that DTI is the most effective imaging modality that has been used to define the microstructure of muscle and hence, could be optimal to image the MTrP. HARDI and DKI are techniques with theoretical potential for analysis of muscle, which may provide more detailed information representative of finer muscle structural features. Future research utilizing MRI techniques to image muscle are necessary to provide a more robust means of imaging skeletal muscle and the MTrP. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
5. The association among skeletal muscle phosphocreatine recovery, adiposity, and insulin resistance in children.
- Author
-
Wells, Greg D., Banks, Laura, Caterini, Jessica E., Thompson, Sara, Noseworthy, Michael D., Rayner, Tammy, Syme, Catriona, McCrindle, Brian W., and Hamilton, Jill
- Subjects
AEROBIC exercises ,BODY weight ,INSULIN resistance ,METABOLISM ,CHILDHOOD obesity ,PHOSPHOCREATINE ,REGRESSION analysis ,STATISTICS ,DATA analysis ,OXIDATIVE stress ,AEROBIC capacity ,COOLDOWN ,CROSS-sectional method ,CASE-control method ,SKELETAL muscle - Abstract
Background: Obesity is associated with cardiometabolic disturbances, which may have significant implications for musculoskeletal health and exercise tolerance. Objective: We sought to determine the association between muscle structure, function, and metabolism in adolescents across the weight spectrum. Methods: This cross‐sectional case–control study included overweight and obese participants (n = 24) 8–18 years of age with a body mass index (BMI) ≥ 85th percentile for age and gender, and non‐obese participants (n = 24) with a BMI < 85th percentile. Body composition, physical activity, peak aerobic capacity, cardiometabolic blood markers and insulin resistance (measured by the homeostatic model assessment of insulin resistance, HOMA‐IR), skeletal muscle mitochondrial oxidative capacity (via 31Phosphorous‐Magnetic Resonance Spectroscopy, 31P‐MRS, to assess phosphocreatine (PCr) recovery after exercise), and extramyocellular and intramyocellular lipid (IMCL) levels (via 1Hydrogen‐MRS) were assessed. Stepwise regression was performed to examine the factors associated with oxidative capacity. Results: bese and overweight patients had similar age, height, and physical activity to non‐obese controls, but obese and overweight participants exhibited higher insulin resistance. Obese and overweight participants had longer PCr recovery than non‐obese controls following 5x30s of moderate‐intensity exercise (51.2 ± 20.1 s vs. 23.9 ± 7.5 s, p = 0.004). In univariate correlation analysis, impaired PCr recovery was associated with a higher BMI z‐score (rs = 0.51, p < 0.001), circulating triglycerides (rs = 0.41, p = 0.005), and HOMA‐IR (rs = 0.46, p = 0.001). In stepwise multivariate regression analysis, impaired PCr recovery was associated with a higher BMI z‐score (β = 0.47, p = 0.002), but not insulin resistance (β = 0.07, p = 0.07) or circulating triglycerides (β = 0.16 p = 0.33). Conclusion: A slower phosphocreatine recovery following aerobic exercise is strongly associated with increasing adiposity. A slower metabolic recovery following aerobic exercise stress suggests that endurance exercise training in obese adolescents may be an optimal strategy to target exercise intolerance in this cohort. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
6. Safe MRI-Compatible electrical muscle stimulation (EMS) system.
- Author
-
Akbari, Alireza, Rockel, Conrad P., Kumbhare, Dinesh A., and Noseworthy, Michael D.
- Subjects
MAGNETIC resonance imaging equipment ,DIAGNOSTIC imaging equipment ,MOLECULAR diagnosis ,SKELETAL muscle physiology ,OXYGEN metabolism ,ELECTRODES ,ELECTROTHERAPEUTICS ,PHOSPHOCREATINE ,RESEARCH evaluation ,MEDICAL equipment safety measures ,PRODUCT design ,MEDICAL equipment reliability ,SKELETAL muscle ,MEDICAL artifacts ,EQUIPMENT & supplies - Abstract
Purpose: To develop an inexpensive magnetic resonance imaging (MRI)-compatible electrical muscle stimulation (EMS) unit and test it for safety and efficacy.Materials and Methods: A simple MRI-compatible EMS device was developed using radiofrequency (RF) translucent electrodes at 3T. RF heating concerns were assessed using optical temperature measurements at electrode sites, during scanning of a phantom. EMS efficacy and consistency was investigated through in vivo (n = 5) measures of 31 P-MRS phosphocreatine (PCr) reduction, and altered blood oxygen level-dependent (BOLD) signal and the results were compared to effects from equivalent voluntary effort on the same subjects.Results: The presence of an EMS pulse did not interfere with the T2 * signal in a phantom. However, signal-to-noise ratio (SNR) was reduced by 70% at electrode sites, but only by 10% 4 cm distally. Under RF intense conditions, the temperature at the electrode site increased by only 4.7°C over a 16-minute time span. In vivo muscle stimulation resulted in 13.5 ± 1.8% reduction in PCr, which was not significantly (P < 0.195) different from voluntary contraction. Reproducible muscle BOLD signal changes following EMS were noted, with a maximal increase of 10.0 ± 2.6% seen in the central soleus. For soleus and gastrocnemius compartments, EMS produced significantly higher BOLD signal change compared to voluntary contraction (P < 0.05).Conclusion: A safe and inexpensive MRI-compatible EMS unit can be easily built for evaluating muscle function and metabolism within a 3T MRI scanner. Clinical applications might include evaluating skeletal muscle function in patients with limited or absent voluntary skeletal motor function or inadequate exercise capacity. J. Magn. Reson. Imaging 2016;44:1530-1538. [ABSTRACT FROM AUTHOR]- Published
- 2016
- Full Text
- View/download PDF
7. Motion and distortion correction of skeletal muscle echo planar images.
- Author
-
Davis, Andrew D. and Noseworthy, Michael D.
- Subjects
- *
SKELETAL muscle , *ECHO-planar imaging , *BLOOD flow , *MEDICAL artifacts , *MAGNETIC resonance imaging , *TIME series analysis - Abstract
This paper examines two artifacts facing researchers who use gradient echo (GRE) echo planar imaging (EPI) for time series studies of skeletal muscles in limbs. The first is through-plane blood flow during the acquisition, causing a vessel motion artifact that inhibits proper motion correction of the data. The second is distortion of EPI images caused by B 0 field inhomogeneities. Though software tools are available for correcting these artifacts in brain EPI images, the tools do not perform well on muscle images. The severity of the two artifacts was described using image similarity measures, and the data was processed with both a conventional motion correction program and custom written tools. The conventional program did not perform well on the limb images, in fact significantly degrading image quality in some trials. Data is presented which proves that arterial pulsatile signal caused the impairment in motion correction. The new tools were shown to perform much better, achieving substantial motion correction and distortion correction of the muscle EPI images. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
8. An exploration of diffusion tensor eigenvector variability within human calf muscles.
- Author
-
Rockel, Conrad and Noseworthy, Michael D.
- Subjects
SKELETAL muscle ,LEG ,ALGORITHMS ,DIAGNOSTIC imaging ,MAGNETIC resonance imaging ,COMPUTERS in medicine ,RESEARCH evaluation ,ANATOMY - Abstract
Purpose: To explore the effect of diffusion tensor imaging (DTI) acquisition parameters on principal and minor eigenvector stability within human lower leg skeletal muscles.Materials and Methods: Lower leg muscles were evaluated in seven healthy subjects at 3T using an 8-channel transmit/receive coil. Diffusion-encoding was performed with nine signal averages (NSA) using 6, 15, and 25 directions (NDD). Individual DTI volumes were combined into aggregate volumes of 3, 2, and 1 NSA according to number of directions. Tensor eigenvalues (λ1 , λ2 , λ3 ), eigenvectors (ε1 , ε2 , ε3 ), and DTI metrics (fractional anisotropy [FA] and mean diffusivity [MD]) were calculated for each combination of NSA and NDD. Spatial maps of signal-to-noise ratio (SNR), λ3 :λ2 ratio, and zenith angle were also calculated for region of interest (ROI) analysis of vector orientation consistency.Results: ε1 variability was only moderately related to ε2 variability (r = 0.4045). Variation of ε1 was affected by NDD, not NSA (P < 0.0002), while variation of ε2 was affected by NSA, not NDD (P < 0.0003). In terms of tensor shape, vector variability was weakly related to FA (ε1 :r = -0.1854, ε2 : ns), but had a stronger relation to the λ3 :λ2 ratio (ε1 :r = -0.5221, ε2 :r = -0.1771). Vector variability was also weakly related to SNR (ε1 :r = -0.2873, ε2 :r = -0.3483). Zenith angle was found to be strongly associated with variability of ε1 (r = 0.8048) but only weakly with that of ε2 (r = 0.2135).Conclusion: The second eigenvector (ε2 ) displayed higher directional variability relative to ε1 , and was only marginally affected by experimental conditions that impacted ε1 variability. [ABSTRACT FROM AUTHOR]- Published
- 2016
- Full Text
- View/download PDF
9. Phosphorus magnetic resonance spectroscopy and imaging (31P-MRS/MRSI) as a window to brain and muscle metabolism: A review of the methods.
- Author
-
Santos-Díaz, Alejandro and Noseworthy, Michael D.
- Subjects
NUCLEAR magnetic resonance spectroscopy ,BRAIN metabolism ,MUSCLE metabolism ,MAGNETIC resonance imaging ,SIGNAL-to-noise ratio ,SKELETAL muscle - Abstract
Phosphorus magnetic resonance spectroscopy and spectroscopic imaging (
31 P-MRS/MRSI) non-invasively provide very important information regarding energy metabolism as they can detect high-energy metabolites and membrane phospholipids in vivo. They have repeatedly proven their utility in the study of healthy and disease conditions in skeletal muscle and brain tissue, as many disorders are related to imbalances in bioenergetics processes. However, they are not often used in a clinic setting, as there are technical challenges imposed by the low sensitivity and low concentration of metabolites leading to low signal to noise ratio (SNR), coarse spatial resolution and very long acquisition times. This paper presents an overview of the main techniques used for the acquisition, data reconstruction and processing of31 P-MRS/MRSI experiments with emphasis in methodological aspects, as well as some of their main applications in the study of skeletal muscle and brain tissue. Also, recent advances in the development of accelerated methods for acquisition of31 P-MR data are discussed. [ABSTRACT FROM AUTHOR]- Published
- 2020
- Full Text
- View/download PDF
10. Temporal Diffusion MRI of Post-Exercise Human Calf Muscles
- Author
-
Rockel, Conrad P, Noseworthy, Michael D, and Biomedical Engineering
- Subjects
exercise ,diffusion ,magnetic resonance imaging ,skeletal muscle - Abstract
Diffusion tensor imaging (DTI) is a magnetic resonance imaging (MRI) method that resolves structures by three-dimensional measurement of water movement, and has shown to benefit studies of anisotropic tissues such as brain and skeletal muscle. While many studies have used DTI to non-invasively study static tissue architecture, little attempt has been made to use this technique to temporally characterize muscle during post-exercise recovery. Thus, the goal of this work was to use DTI to study the timecourse of changes in skeletal muscle following exercise. The first study was performed to test stability of DTI eigenvectors (ε1 ε2 ε3), and to determine how time-expensive parameters such as increased number of diffusion directions (NDD) or signal averages (NSA) improve vector stability. The ε2 vector was found to have more directional variability than ε1, and showed less improvement than ε1 with increased NDD or NSA. Furthermore, decreasing directional variability of ε1 was correlated with increasing NDD, not NSA (p
- Published
- 2016
11. LOWER LIMB MUSCLE ASSESSMENT USING DIFFUSION TENSOR AND BLOOD OXYGEN-LEVEL DEPENDENT IMAGING
- Author
-
Elzibak, Alyaa H., Noseworthy, Michael D., and Medical Physics
- Subjects
Skeletal Muscle ,Blood Oxygen-Level Dependent (BOLD) Imaging ,Physics ,Magnetic Resonance Imaging (MRI) ,Lower Limb ,Diffusion Tensor Imaging (DTI) - Abstract
Diffusion tensor (DT) and blood oxygen-level dependent (BOLD) imaging are two noninvasive magnetic resonance (MR) techniques that have been used to probe skeletal muscle microstructure and microvasculature, respectively. Over a series of four studies, the work in this thesis aimed at furthering our understanding of baseline DT metrics and BOLD signals in lower limb muscles (calf and foot) of healthy young subjects. Since postural changes have been shown to alter numerous quantities, including fluid volumes and muscle cross sectional area, DT indices and BOLD signal characteristics were examined in response to movement from upright to supine position. Reductions of 3.2-6.7% and 3.4-7.5% were measured in calf DT eigenvalues and apparent diffusion coefficient (ADC) in the various muscles, following 34 and 64 minutes of supine rest, respectively (P Establishment of baseline diffusion metrics in the foot region was feasible (chapter 6). Examination of foot DT indices in response to positional change showed that the metrics decreased from 2.7-4.6% following 34 minutes of supine rest (P Doctor of Philosophy (PhD)
- Published
- 2014
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.