Study design
Investigation of the automation of radiological features from magnetic resonance images (MRIs) of the lumbar spine.
Objective
To automate the process of grading lumbar intervertebral ...discs and vertebral bodies from MRIs.
Summary of background data
MR imaging is the most common imaging technique used in investigating low back pain (LBP). Various features of degradation, based on MRIs, are commonly recorded and graded, e.g., Modic change and Pfirrmann grading of intervertebral discs. Consistent scoring and grading is important for developing robust clinical systems and research. Automation facilitates this consistency and reduces the time of radiological analysis considerably and hence the expense.
Methods
12,018 intervertebral discs, from 2009 patients, were graded by a radiologist and were then used to train: (1) a system to detect and label vertebrae and discs in a given scan, and (2) a convolutional neural network (CNN) model that predicts several radiological gradings. The performance of the model, in terms of class average accuracy, was compared with the intra-observer class average accuracy of the radiologist.
Results
The detection system achieved 95.6% accuracy in terms of disc detection and labeling. The model is able to produce predictions of multiple pathological gradings that consistently matched those of the radiologist. The model identifies ‘Evidence Hotspots’ that are the voxels that most contribute to the degradation scores.
Conclusions
Automation of radiological grading is now on par with human performance. The system can be beneficial in aiding clinical diagnoses in terms of objectivity of gradings and the speed of analysis. It can also draw the attention of a radiologist to regions of degradation. This objectivity and speed is an important stepping stone in the investigation of the relationship between MRIs and clinical diagnoses of back pain in large cohorts.
Level of Evidence: Level 3.
Variations in paraspinal muscle cross-sectional area (CSA) and composition, particularly of the multifidus muscle, have been of interest with respect to risk of, and recovery from, low back pain ...problems. Several investigators have reported on the reliability of such muscle measurements using various protocols and image analysis programs. However, there is no standard protocol for tissue segmentation, nor has there been an investigation of reliability or agreement of measurements using different software.
The purpose of this study was to provide a detailed muscle measurement protocol and determine the reliability and agreement of associated paraspinal muscle composition measurements obtained with 2 commonly used image analysis programs: OsiriX and ImageJ.
This was a measurement reliability study.
Lumbar magnetic resonance images of 30 individuals were randomly selected from a cohort of patients with various low back conditions. Muscle CSA and composition measurements were acquired from axial T2-weighted magnetic resonance images of the multifidus muscle, the erector spinae muscle, and the 2 muscles combined at L4-L5 and S1 for each participant. All measurements were repeated twice using each software program, at least 5 days apart. The assessor was blinded to all earlier measurements.
The intrarater reliability and standard error of measurement (SEM) were comparable for most measurements obtained using OsiriX or ImageJ, with reliability coefficients (intraclass correlation coefficients ICCs) varying between .77 and .99 for OsiriX and .78 and .99 for ImageJ. There was similarly excellent agreement between muscle composition measurements using the 2 software applications (inter-software ICCs = .81-.99).
The high degree of inter-software measurement reliability may not generalize to protocols using other commercial or custom-made software.
The proposed method to investigate paraspinal muscle CSA, composition, and side-to-side asymmetry was highly reliable, with excellent agreement between the 2 software programs.
Purpose
To investigate asymmetry in size and composition of the multifidus and erector spinae in patients with posterolateral disc herniation and concordant radicular symptoms, and determine whether ...symptom duration is associated with degree of asymmetry.
Methods
Thirty-three patients diagnosed with posterolateral disc herniation at L4–L5 verified on imaging and concordant leg pain were included. Multifidus and erector spinae cross-sectional area (CSA), functional cross-sectional area (FCSA, fat-free area), signal intensity and ratio of FCSA to total CSA were measured bilaterally from
T
2
-weighted axial magnetic resonance imaging (MRI) at L3–L4, L4–L5, L5–S1 and S1 levels.
Results
No side-to-side differences in multifidus CSA, FCSA, and ratio of FCSA/CSA reached statistical significance at any spinal level. The multifidus signal intensity at L5–S1 was significantly greater (more fatty infiltration) on the side of the disc herniation. The erector spinae FCSA (lean muscle mass) at L5–S1 was found to be significantly smaller on the side of the herniation and the ratio of FCSA/CSA was smaller (more fatty infiltration) on the side of the herniation at L4–L5 and L5–S1. The degree of muscle asymmetry was not associated with symptoms duration.
Conclusions
There was no significant asymmetry of the multifidus at spinal level above, same or level below the disc herniation. Instead, variations in muscle composition were observed, with greater fat infiltration on the side and at spinal levels adjacent to the disc herniation. Muscle asymmetry was not correlated with symptom duration.
Twin studies suggest that both disc degeneration and back pain have a genetic component. We were interested in estimating the heritability of low back pain in men and examining whether genetic ...influences on back pain are mediated through genetic influences on disc degeneration. Thus, we conducted a classic twin study with multivariate quantitative genetic models to estimate the degree to which genetic (or environmental) effects on back pain were correlated with genetic (or environmental) effects on disc degeneration. Subjects included 147 monozygotic and 153 dizygotic male twin pairs (N=600 subjects) from the population-based Finnish Twin Cohort. All subjects underwent lumbar magnetic resonance imaging and completed an extensive interview, including back pain history and exposure to suspected risk factors. Disc height narrowing was the degenerative finding most associated with pain history, and was used to index disc degeneration in the models. Statistically significant genetic correlations were found for disc height narrowing and different definitions of back pain, such as duration of the worst back pain episode (r(g)=0.46) and hospitalization for back problems (r(g)=0.49), as well as disability in the previous year from back pain (r(g)=0.33). The heritability estimates for these back pain variables ranged from 30% to 46%. There also were statistically significant, but weaker, environmental correlations for disc height narrowing with back symptoms over the prior year. A substantial minority of the genetic influences on pain was due to the same genetic influences affecting disc degeneration. This suggests that disc degeneration is one pathway through which genes influence back pain.
Low back pain Vlaeyen, Johan W S; Maher, Chris G; Wiech, Katja ...
Nature reviews. Disease primers,
12/2018, Volume:
4, Issue:
1
Journal Article
Peer reviewed
Open access
Low back pain affects individuals of all ages and is a leading contributor to disease burden worldwide. Despite advancements in assessment and treatment methods, the management of low back pain ...remains a challenge for researchers and clinicians alike. One reason for the limited success in identifying effective treatments is the large variation in the manifestations, possible causes, precipitating and maintaining factors, course, prognosis and consequences in terms of activity interference and quality of life. However, despite these challenges, steady progress has been achieved in the understanding of back pain, and important steps in the understanding of the psychological and social risk factors, genetics and brain mechanisms of low back pain have been made. These new findings have given impetus to the development of new diagnostic procedures, evidence-based screening methods and more targeted interventions, which underscore the need for a multidisciplinary approach to the management of low back pain that integrates biological, psychological and social aspects.
Paraspinal muscle asymmetry in cross-sectional area (CSA) and composition have been associated with low back pain and pathology. However, substantial multifidus muscle asymmetry also has been ...reported in men who were asymptomatic, and little is known about other factors influencing asymmetry.
The goal of this study was to identify behavioral, environmental, and constitutional factors associated with paraspinal muscle asymmetry.
A cross-sectional study of 202 adult male twins was conducted.
Data were collected through a structured interview, physical examination, and magnetic resonance imaging. Measurements of multifidus and erector spinae muscle CSA and the ratio of fat-free CSA to total CSA were obtained from T2-weighted axial images at L3-L4 and L5-S1.
In multivariable analyses, greater asymmetry in multifidus CSA at L3-L4 was associated with lower occupational physical demands and less disk height narrowing. Handedness was the only factor associated with multifidus muscle CSA asymmetry at L5-S1. For the erector spinae muscle, greater age, handedness, and disk height narrowing were associated with CSA asymmetry at L3-L4, and sports activity, handedness, disk height narrowing, and familial aggregation were associated with CSA asymmetry at L5-S1. In multivariable analyses of asymmetry in muscle composition, familial aggregation explained 7% to 20% of the variance in multifidus and erector spinae muscle side-to-side differences at both levels measured. In addition, handedness and pain severity entered the model for erector spinae muscle asymmetry at L5-S1, and disability, handedness, and disk height narrowing entered the model for multifidus muscle asymmetry at L5-S1.
Reliance on participants' recall for low back pain history, occupation, and physical activity levels was a limitation of this study.
Few of the factors investigated were associated with paraspinal muscle asymmetry, and associations were inconsistent and modest, explaining little of the variance in paraspinal muscle asymmetry.
Purpose
Clinical observations suggest that endplate shape and size are related to complications of disc arthroplasty surgery. Yet, the morphology of the vertebral endplate has not been well defined. ...This study was conducted to characterize the morphology of lumbar vertebral endplates and to quantify their morphometrics using radiographic, visual and digital measures.
Methods
A total of 591 vertebral endplates from 76 lumbosacral spines of men were studied (mean age 51.3 years). The shape of the vertebral endplates was classified as concave, flat and irregular, and was evaluated from both radiographs and cadaveric samples. Each endplate was further digitized using a laser scanner to quantify diameters, surface area and concavity for the whole endplate and its components (central endplate and epiphyseal rim). The morphological characteristics and morphometrics of the vertebral endplates were depicted.
Results
In both radiographic and visual assessments, more cranial endplates (relative to the disc) were concave and more caudal endplates were flat at all disc levels (
p
< 0.001). On average, the mean concavity depth was 1.5 mm for the cranial endplate and 0.7 mm for the caudal endplate. From L1/2 down to L5/S1 discs, the vertebral endplate gradually changed into a more oval shape. The central endplate was approximately 70 % of the diameter of the whole endplate and the width of the epiphyseal rim varied from 3 to 7 mm.
Conclusions
There is marked morphological asymmetry between the two adjacent endplates of a lumbar intervertebral disc: the cranial endplate is more concave than the caudal endplate. The size and shape of the vertebral endplate also vary considerably between the upper and lower lumbar regions.
Abstract
Objective
Back pain is an elusive symptom complicated by a variety of possible causes, precipitating and maintaining factors, and consequences. Notably, the underlying pathology remains ...unknown in a significant number of cases. Changes to the intervertebral disc (IVD) have been associated with back pain, leading many to postulate that the IVD may be a direct source of pain, typically referred to as discogenic back pain. Yet despite decades of research into the neuroanatomy of the IVD, there is a lack of consensus in the literature as to the distribution and function of neural elements within the tissue. The current scoping review provides a comprehensive systematic overview of studies that document the topography, morphology, and immunoreactivity of neural elements within the IVD in humans.
Method
Articles were retrieved from six separate databases in a three-step systematic search and were independently evaluated by two reviewers.
Results
Three categories of neural elements were described within the IVD: perivascular nerves, sensory nerves independent of blood vessels, and mechanoreceptors. Nerves were consistently localized within the outer layers of the annulus fibrosus. Neural ingrowth into the inner annulus fibrosus and nucleus pulposus was found to occur only in degenerative and disease states.
Conclusion
While the pattern of innervation within the IVD is clear, the specific topographic arrangement and function of neural elements in the context of back pain remains unclear.
Background The current literature supports the effectiveness of exercise, education, and self-management interventions for the long-term management of persistent low back pain. However, there is ...significant uncertainty about the implementation of interventions related to barriers, facilitators, and patient's preferences. This study will evaluate the Back to Living Well program implementation from a participant and organizational perspective. More specifically we address the following objectives: 1) identify program barriers and facilitators from participants' perspectives, 2) identify factors related to program, personal and contextual factors that contribute to negative and positive outcomes, and outcome trajectories, 3) identify factors influencing participants' selection of an in-person or e-health program, and 4) evaluate program specific barriers and facilitators from the organization and care delivery perspectives. Methods This study will utilize a mixed-method convergent design including a longitudinal cohort strand and a longitudinal qualitative interview strand. The RE-AIM framework will be used to assess program implementation. Participants (n = 90, 1:1: in person or virtual) who choose to register in the program as well as staff (n = 10 to 15) involved in the delivery of the program will be invited to participate. Participants will participate in a 12-week physical activity, education, and self-management program. Implementation outcomes will be measured at 3-, 6-, 12-months, and six months after the end of the follow-ups. Interview scripts and directed content analysis will be constructed based on the Theoretical Domains Framework and the Neuromatrix Model of Pain, Theoretical Domains Framework. Staff interviews will be constructed and analyzed using the Consolidated Framework for Implementation Research. Participants will also complete pain, disability, quality of life and psychological questionnaires, wear an activity tracker at all time points, and complete weekly pain and activity limitation questions using a mobile application. Discussion The study results will provide evidence to inform potential future implementation of the program. An effective, appropriately targeted, and well implemented exercise program for the long-term management (i.e., tertiary prevention) of LBP could minimize the burden of the condition on patients, the health care system and society. Trial registration ClinicalTrials.gov NCT05929846. This (Registration Date: July 3 2023) study has been approved by the Hamilton Integrated Research Ethics Board Project ID#15,354. Keywords: Implementation, Low back pain, Community-based programs, Tertiary prevention, Self-management
Essentials
Pregnancy is a risk factor for thrombosis.
Management of thrombosis risk in pregnancy remains a challenge.
Prophylaxis needs to be personalized.
Our score may be a helpful tool for the ...management of pregnancies at high risk of thrombosis.
Summary
Background
Patients with thrombophilia and/or a history of venous thromboembolism (VTE) are at risk of thrombosis during pregnancy. A risk score for pregnancies with an increased risk of VTE was previously described by our group (Lyon VTE score).
Objectives
The aim of this prospective study was to assess the efficacy and safety of our score‐based prophylaxis strategy in 542 pregnancies managed between 2005 and 2015 in Lyon University Hospitals.
Patients/Methods
Of 445 patients included in the study, 36 had several pregnancies during the study period. Among these 445 patients, 279 had a personal history of VTE (62.7%), 299 patients (67.2%) had a thrombophilia marker, and 131 (29.4%) thrombophilic women had a personal history of VTE. During pregnancy, patients were assigned to one of three prophylaxis strategies according to the risk scoring system.
Results
In the antepartum period, low molecular weight heparin (LMWH) prophylaxis was prescribed to 64.5% of patients at high risk of VTE. Among them, 34.4% were treated in the third trimester only, and 30.1% were treated throughout pregnancy. During the postpartum period, all patients received LMWH for at least 6 weeks. Two antepartum‐related VTEs (0.37%; one with a score of < 3 and the other with a score of > 6) and four postpartum‐related VTEs (0.73%; three with scores of 3–5 and one with a score of > 6) occurred. No case of pulmonary embolism was observed during the study period. The rate of bleeding was 0.37%. No serious bleeding requiring transfusions or surgery occurred during the study period.
Conclusion
The use of a risk score may provide a rational decision process to implement safe and effective antepartum thromboprophylaxis in pregnant women at high risk of VTE.
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