Spinal degeneration is associated with lumbar multifidus morphology in secondary care patients with low back or leg pain

Associations between multifidus muscle morphology and degenerative pathologies have been implied in patients with non-specific low back pain, but it is unknown how these are influenced by pathology severity, number, or distribution. MRI measures of pure multifidus muscle cross-sectional area (CSA) were acquired from 522 patients presenting with low back and/or leg symptoms in an outpatient clinic. We explored cross-sectional associations between the presence, distribution, and/or severity of lumbar degenerative pathologies (individually and in aggregate) and muscle outcomes in multivariable analyses (beta coefficients [95% CI]). We identified associations between lower pure multifidus muscle CSA and disc degeneration (at two or more levels): − 4.51 [− 6.72; − 2.3], Modic 2 changes: − 4.06 [− 6.09; − 2.04], endplate defects: − 2.74 [− 4.58; − 0.91], facet arthrosis: − 4.02 [− 6.26; − 1.78], disc herniations: − 3.66 [− 5.8; − 1.52], and when > 5 pathologies were present: − 6.77 [− 9.76; − 3.77], with the last supporting a potential dose–response relationship between number of spinal pathologies and multifidus morphology. Our findings could hypothetically indicate that these spinal and muscle findings: (1) are part of the same degenerative process, (2) result from prior injury or other common antecedent events, or (3) have a directional relationship. Future longitudinal studies are needed to further examine the complex nature of these relationships

Evaluation of three different methods of distance learning for postgraduate diagnostic imaging education: A pilot study

Objective : The purpose of this study was to evaluate the perceived effectiveness and learning potential of 3 Web-based educational methods in a postgraduate radiology setting. Methods : Three chiropractic radiology faculty from diverse geographic locations led mini-courses using asynchronous discussion boards, synchronous Web conferencing, and asynchronous voice-over case presentations formatted for Web viewing. At the conclusion of each course, participants filled out a 14-question survey (using a 5-point Likert scale) designed to evaluate the effectiveness of each method in achieving specified course objectives and goals and their satisfaction when considering the learning potential of each method. The mean, standard deviation, and percentage agreements were tabulated. Results : Twenty, 15, and 10 participants completed the discussion board, Web conferencing, and case presentation surveys, respectively. All educational methods demonstrated a high level of agreement regarding the course objective (total mean rating >4.1). The case presentations had the highest overall rating for achieving the course goals; however, all but one method still had total mean ratings >4.0 and overall agreement levels of 70%-100%. The strongest potential for interactive learning was found with Web conferencing and discussion boards, while case presentations rated very low in this regard. Conclusions : The perceived effectiveness in achieving the course objective and goals was high for each method. Residency-based distance education may be a beneficial adjunct to current methods of training, allowing for international collaboration. When considering all aspects tested, there does not appear to be a clear advantage to any one method. Utilizing various methods may be most appropriate

Assessing lumbar paraspinal muscle cross-sectional area and fat composition with T1 versus T2-weighted magnetic resonance imaging: Reliability and concurrent validity

Purpose Studies using magnetic resonance imaging to assess lumbar multifidus cross-sectional area frequently utilize T1 or T2-weighted sequences, but seldom provide the rationale for their sequence choice. However, technical considerations between their acquisition protocols could impact on the ability to assess lumbar multifidus anatomy or its fat/muscle distinction. Our objectives were to examine the concurrent validity of lumbar multifidus morphology measures of T2 compared to T1-weighted sequences, and to assess the reliability of repeated lumbar multifidus measures. Methods The lumbar multifidus total cross-sectional area of 45 patients was measured bilaterally at L4 and L5, with histogram analysis determining the muscle/fat threshold values per muscle. Images were later re-randomized and re-assessed for intra-rater reliability. Matched images were visually rated for consistency of outlining between both image sequences. Bland-Altman bias, limits of agreement, and plots were calculated for differences in total cross-sectional area and percentage fat between and within sequences, and intra-rater reliability analysed. Results T1-weighted total cross-sectional area measures were systematically larger than T2 (0.2 cm2), with limits of agreement <±10% at both spinal levels. For percentage fat, no systematic bias occurred, but limits of agreement approached ±15%. Visually, muscle outlining was consistent between sequences, with substantial mismatches occurring in <5% of cases. Intra-rater reliability was excellent (ICC: 0.981–0.998); with bias and limits of agreement less than 1% and ±5%, respectively. Conclusion Total cross-sectional area measures and outlining of muscle boundaries were consistent between sequences, and intra-rater reliability for total cross-sectional area and percentage fat was high indicating that either MRI sequence could be used interchangeably for this purpose. However, further studies comparing the accuracy of various methods for distinguishing fat from muscle are recommended

Sampling Theorem and Discrete Fourier Transform on the Riemann Sphere

Using coherent-state techniques, we prove a sampling theorem for Majorana's (holomorphic) functions on the Riemann sphere and we provide an exact reconstruction formula as a convolution product of $N$ samples and a given reconstruction kernel (a sinc-type function). We also discuss the effect of over- and under-sampling. Sample points are roots of unity, a fact which allows explicit inversion formulas for resolution and overlapping kernel operators through the theory of Circulant Matrices and Rectangular Fourier Matrices. The case of band-limited functions on the Riemann sphere, with spins up to $J$, is also considered. The connection with the standard Euler angle picture, in terms of spherical harmonics, is established through a discrete Bargmann transform.Comment: 26 latex pages. Final version published in J. Fourier Anal. App

A comparison of spatially explicit and classic regression modelling of live coral cover using hyperspectral remote-sensing data in the Al Wajh lagoon, Red Sea

Live coral is a key component of the Al Wajh marine reserve in the Red Sea. The management of this reserve is dependent on a sound understanding of the existing spatial distribution of live coral cover and the environmental factors influencing live coral at the landscape scale. This study uses remote-sensing techniques to develop ordinary least squares and spatially lagged autoregressive explanatory models of the distribution of live coral cover inside the Al Wajh lagoon, Saudi Arabia. Live coral was modelled as a response to environmental controls such as water depth, the concentration of suspended sediment in the water column and exposure to incident waves. Airborne hyperspectral data were used to derive information on live coral cover as a response (dependent) variable at the landscape scale using linear spectral unmixing. Environmental controls (explanatory variables) were derived from a physics-based inversion of the remote-sensing dataset and validated against field-collected data. For spatial regression, cases referred to geographical locations that were explicitly drawn on in the modelling process to make use of the spatially dependent nature of coral cover controls. The transition from the ordinary least squares model to the spatially lagged model was accompanied by a marked growth in explanatory power (R 2 = 0.26 to 0.76). The theoretical implication that follows is that neighbourhood context interactions play an important role in determining live coral cover. This provides a persuasive case for building geographical considerations into studies of coral distribution

Developing clinical decision making skills: A collaborative, evidence based project for integrating diagnostic imaging into the clinical work-up

The need to transition students from an academic mindset towards an evidence based approach to the clinical work-up of their client/patient is an important component of the training of chiropractic students. Within the broad spectrum of diagnostic procedures students must become familiar with, imaging is an important tool in their decision making armament. With increasing awareness of the need to apply evidence based practice to this decision making process, the concept of "just do as you were taught" is slowly disappearing from the chiropractic practice ethos. Consequently, as teachers of clinical practice we must begin to place more onus on the students to find and use the best evidence before they "leave the educational nest". To move towards this outcome, we have implemented a unit in the first trimester of our Year 5 chiropractic course in which the students engage in their own, and each others, learning by becoming the principle teachers. Small groups of 4-5 students actively work-up all aspects of a clinical case from its initial presentation, learning how to grapple with clinical uncertainty and seek out the best evidence to support their next step in the diagnostic work-up. Students then present a full case to the class and ultimately develop the notes for the unit and their future clinical practice. This presentation will focus on the thought process underpinning the development of the unit, its basic design and operation, and the role of technology. A brief overview of the outcomes of a post unit survey will be offered. Overall, the students found the concepts and activities of the unit to be of great value in helping them understand how to find and apply new evidence to clinical practice. They felt that having the responsibility of developing the lectures and learning materials for the unit improved their learning experience