Patient-oriented research: An essential driver of learning health system capacity development.

Canada's health system faces a lag in implementing high-quality evidence and research-driven innovation into service delivery, while demonstrating accountability and benefit to the public. To address these challenges, Patient-Oriented Research (POR) builds teams that engage researchers, healthcare providers, decision-makers, and most importantly, patients (people with lived and living experience) in the process of generating and applying evidence to inform health services and decision-making. A Learning Health System (LHS) systematically integrates external evidence with internal data and experience and puts that knowledge into practice in a continuous cycle. Using a POR/LHS example from a BC health authority, we describe nine enablers required to support LHS capacity development. The LHS case study, Walk With Me, addresses a health system high-priority topic: the toxic drug crisis. Understanding the value of learning health systems, along with the enablers required to support and implement them, will empower health leaders to champion and orchestrate positive change.

Symmetry of the fornix using diffusion tensor imaging.

PURPOSE: To: 1) Present fornix tractography in its entirety for 20 healthy individuals to assess variability. 2) Provide individual and groupwise whole tract diffusion parameter symmetry assessments prior to clinical application. 3) Compare whole tract diffusion parameter assessments with tract-based spatial statistics (TBSS). MATERIALS AND METHODS: Diffusion tensor imaging (DTI) data were acquired on a 3T Siemens magnetic resonance imaging (MRI) system using a single-shot spin echo planar imaging (EPI) sequence. Individual fornix tractography was conducted and whole tract diffusion parameter symmetries assessed. Whole tract results were compared with asymmetry contrasts conducted with voxelwise statistical analysis of diffusion parameters using TBSS. RESULTS: The fornix tract could be visualized in its entirety including the columns, body, crura, and fimbria. Contrary to the crus and body, there were some tractography inconsistencies of the columns and fimbria across subjects. Although whole tract diffusion parameter asymmetries were nonsignificant, fractional anisotropy (FA) values bordered on statistical significance (P = 0.052). Using TBSS, significant FA asymmetries were identified (P ≤ 0.01, corrected). CONCLUSION: The findings demonstrate consistency of fornix tractography as well as some variability in the columns and fimbria. While parametric assessment demonstrates diffusion parameter symmetry, permutation-based TBSS analysis reveals significant FA asymmetries in the crura and fimbriae.

Functional MRI of the thoracic spinal cord during vibration sensation.

PURPOSE: To demonstrate that it is possible to acquire accurate functional magnetic resonance images from thoracic spinal cord neurons. MATERIALS AND METHODS: The lower thoracic spinal dermatomes (T7-T11) on the right side of the body were mechanically stimulated by vibration for 15 participants. Neuronal responses to vibration sensation were measured in the thoracic spinal cord using a HASTE sequence on a 3 Tesla MRI system. RESULTS: Signal increases were observed in the corresponding lower thoracic spinal cord segments ipsilateral to the side of stimulation in the dorsal aspect of the spinal cord. CONCLUSION: This is the first study to provide proof of principle that functional imaging of the entire thoracic spinal cord is possible, by detecting neuronal activity in the thoracic spinal cord during sensory stimulation using spinal fMRI.

Human cervical spinal cord funiculi: investigation with magnetic resonance diffusion tensor imaging.

PURPOSE: To use spinal cord diffusion tensor imaging (DTI) for investigating human cervical funiculi, acquire axial diffusion magnetic resonance imaging (MRI) data with an in-plane resolution sufficient to delineate subquadrants within the spinal cord, obtain corresponding DTI metrics, and assess potential regional differences. MATERIALS AND METHODS: Healthy volunteers were studied with a 3 T Siemens Trio MRI scanner. DTI data were acquired using a single-shot spin echo EPI sequence. The spatial resolution allowed for the delineation of regions of interest (ROIs) in the ventral, dorsal, and lateral spinal cord funiculi. ROI-based and tractography-based analyses were performed. RESULTS: Significant fractional anisotropy (FA) differences were found between ROIs in the dorsal and ventral funiculi (P = 0.0001), dorsal and lateral funiculi (P = 0.015), and lateral and ventral funiculi (P = 0.0002). Transverse diffusivity was significantly different between ROIs in the ventral and dorsal funiculi (P = 0.003) and the ventral and lateral funiculi (P = 0.004). Tractography-based quantifications revealed DTI parameter regional differences that were generally consistent with the ROI-based analysis. CONCLUSION: Original contributions are: 1) the use of a tractography-based method to quantify DTI metrics in the human cervical spinal cord, and 2) reported DTI values in various funiculi at 3 T.

Tractography of Meyer's Loop asymmetries.

PURPOSE: The purpose of the current study was to use diffusion tensor imaging (DTI) to conduct tractography of the optic radiations (OR) and its component bundles and to assess both the degree of hemispheric asymmetry and the inter-subject variability of Meyer's Loop (ML). We hypothesized that there are significant left versus right differences in the anterior extent of ML to the temporal pole (TP) in healthy subjects. MATERIALS AND METHODS: DTI data were acquired on a 3T Siemens MRI system using a single-shot Spin Echo EPI sequence. The dorsal, central and ML bundles of the OR were tracked and visualized in forty hemispheres of twenty healthy volunteers. The uncinate fasciculus (UF) was also tracked in these subjects so that it could be used as a distinct anatomical reference. Measurements were derived for the distance between ML-TP, ML and the temporal horn (ML-TH) and ML and the uncinate fasciculus (ML-UF). Paired difference t-tests were carried out with SPSS 14.0. RESULTS: ML and the UF were successfully tracked and visualized in all 20 volunteers. Significant hemispheric asymmetries were found for all measurements with left distances shorter than the right (P<0.005). In 50% of the subjects the left ML-UF distance was ≤1.9 mm. CONCLUSION: The results support our hypothesis and demonstrate that left ML-TP distances are significantly shorter than right ML-TP distances. These asymmetries are also reflected in shorter left distances between ML-TH and ML-UF. Moreover, these results are of interest to left-sided temporal lobe epilepsy surgery because it is not only more likely to disturb the anterior extent of ML but also renders the often closely located posterior aspect of the left UF more vulnerable to potential surgical impact.

Default mode network functional connectivity altered in failed back surgery syndrome.

UNLABELLED: The purpose of this study was to identify alterations in the default mode network of failed back surgery syndrome patients as compared to healthy subjects. Resting state functional magnetic resonance imaging was conducted at 3 Tesla and data were analyzed with an independent component analysis. Results indicate an overall reduced functional connectivity of the default mode network and recruitment of additional pain modulation brain regions, including dorsolateral prefrontal cortex, insula, and additional sensory motor integration brain regions, including precentral and postcentral gyri, for failed back surgery syndrome patients. PERSPECTIVE: This article presents alterations in the default mode network of chronic low back pain patients with failed back surgery syndrome as compared to healthy participants.

Diffusion abnormality maps in demyelinating disease: correlations with clinical scores.

BACKGROUND AND PURPOSE: Magnetic resonance imaging (MRI) has been explored as a noninvasive tool to assess pathology in multiple sclerosis (MS) patients. However, the correlation between classical MRI measures and physical disability is modest in MS. The diffusion tensor imaging (DTI) MRI technique holds particular promise in this regard. The present study shows brain regions where FA and individual diffusivities abnormalities are present and check their correlations with physical disability clinical scores. METHODS: Eight patients and 12 matched healthy controls were recruited. The Multiple Sclerosis Functional Composite was administered. For MR-DTI acquisitions, a Genesis Signa 1.5 T MR system, an EP/SE scanning sequence, 25 gradient directions were used. RESULTS: Tract Based Spatial Statistics (TBSS) group comparisons showed reduced FA and increased individual diffusivities in several brain regions in patients. Significant correlations were found between FA and: EDSS, 9-HPT(NON)DOM and 25 FW score; between λ2 and: P100 (r&l), 9-HPT(NON)DOM and 25 FW; between λ3 and: 9-HPT(NON)DOM and 25 FW score. CONCLUSIONS: Fractional anisotropy and individual radial diffusivities proved to be important markers of motor disabilities in MS patients when the disease duration mean and the disability scores values range are relatively high.

Convertible pneumatic actuator for magnetic resonance elastography of the brain.

Here we present a novel pneumatic actuator design for brain magnetic resonance elastography (MRE). Magnetic resonance elastography is a phase contrast technique capable of tracing strain wave propagation and utilizing this information for the calculation of mechanical properties of materials and living tissues. In MRE experiments, the acoustic waves are generated in a synchronized way with respect to image acquisition, using various types of mechanical actuators. The unique feature of the design is its simplicity and flexibility, which allows reconfiguration of the actuator for different applications ranging from in vivo brain MRE to experiments with phantoms. Phantom and in vivo data are presented to demonstrate actuator performance.