Quantitative assessment of the lumbar intervertebral disc via T2 shows excellent long-term reliability

Methodologies for the quantitative assessment of the spine tissues, in particular the intervertebral disc (IVD), have not been well established in terms of long-term reliability. This is required for designing prospective studies. 1H water T2 in the IVD (“T2”) has attained wider use in assessment of the lumbar intervertebral discs via magnetic resonance imaging. The reliability of IVD T2 measurements are yet to be established. IVD T2 was assessed nine times at regular intervals over 368 days on six anatomical slices centred at the lumbar spine using a spin-echo multi-echo sequence in 12 men. To assess repeatability, intra-class correlation co-efficients (ICCs), standard error of the measurement, minimal detectable difference and co-efficients of variation (CVs) were calculated along with their 95% confidence intervals. Bland-Altman analysis was also performed. ICCs were above 0.93, with the exception of nuclear T2 at L5/S1, where the ICC was 0.88. CVs of the central-slice nucleus sub-region ranged from 4.3% (average of all levels) to 10.1% for L5/S1 and between 2.2% to 3.2% for whole IVD T2 (1.8% for the average of all levels). Averaging between vertebral levels improved reliability. Reliability of measurements was least at L5/S1. ICCs of degenerated IVDs were lower. Test-retest reliability was excellent for whole IVD and good to excellent for IVD subregions. The findings help to establish the long-term repeatability of lumbar IVD T2 for the implementation of prospective studies and determination of significant changes within individuals

Magnetism in reduced dimensions

We propose a short overview of a few selected issues of magnetism in reduced dimensions, which are the most relevant to set the background for more specialized contributions to the present Special Issue. Magnetic anisotropy in reduced dimensions is discussed, on a theoretical basis, then with experimental reports and views from surface to single-atom anisotropy. Then conventional magnetization states are reviewed, including macrospins, single domains, multidomains, and domain walls in stripes. Dipolar coupling is examined for lateral interactions in arrays, and for interlayer interactions in films and dots. Finally thermally-assisted magnetization reversal and superparamagnetism are presented. For each topic we sought a balance between well established knowledge and recent developments.Comment: 13 pages. Part of a Special Issue of the C. R. Physique devoted to spinelectronics (2005

Chromatin and DNA methylation dynamics during retinoic acid-induced RET gene transcriptional activation in neuroblastoma cells

Although it is well known that RET gene is strongly activated by retinoic acid (RA) in neuroblastoma cells, the mechanisms underlying such activation are still poorly understood. Here we show that a complex series of molecular events, that include modifications of both chromatin and DNA methylation state, accompany RA-mediated RET activation. Our results indicate that the primary epigenetic determinants of RA-induced RET activation differ between enhancer and promoter regions. At promoter region, the main mark of RET activation was the increase of H3K4me3 levels while no significant changes of the methylation state of H3K27 and H3K9 were observed. At RET enhancer region a bipartite chromatin domain was detected in unstimulated cells and a prompt demethylation of H3K27me3 marked RET gene activation upon RA exposure. Moreover, ChIP experiments demonstrated that EZH2 and MeCP2 repressor complexes were associated to the heavily methylated enhancer region in the absence of RA while both complexes were displaced during RA stimulation. Finally, our data show that a demethylation of a specific CpG site at the enhancer region could favor the displacement of MeCP2 from the heavily methylated RET enhancer region providing a novel potential mechanism for transcriptional regulation of methylated RA-regulated loci

Changes in intervertebral disc morphology persist 5 mo after 21-day bed rest

As part of the nutrition- countermeasures (NUC) study in Cologne, Germany in 2010, seven healthy male subjects underwent 21 days of head-down tilt bed rest and returned 153 days later to undergo a second bout of 21-day bed rest. As part of this model, we aimed to examine the recovery of the lumbar intervertebral discs and muscle cross-sectional area (CSA) after bed rest using magnetic resonance imaging and conduct a pilot study on the effects of bed rest in lumbar muscle activation, as measured by signal intensity changes in T2-weighted images after a standardized isometric spinal extension loading task. The changes in intervertebral disc volume, anterior and posterior disc height, and intervertebral length seen after bed rest did not return to prebed-rest values 153 days later. While recovery of muscle CSA occurred after bed rest, increases (P 0.016) in multifidus, psoas, and quadratus lumborum muscle CSA were seen 153 days after bed rest. A trend was seen for greater activation of the erector spinae and multifidus muscles in the standardized loading task after bed rest. Greater reductions of multifidus and psoas CSA muscle and greater increases in multifidus signal intensity with loading were associated with incidence of low back pain in the first 28 days after bed rest (P 0.044). The current study contributes to our understanding of the recovery of the lumbar spine after 21-day bed rest, and the main finding was that a decrease in spinal extensor muscle CSA recovers within 5 mo after bed rest but that changes in the intervertebral discs persist

T2-relaxation time increases in lumbar intervertebral disks after 21d head-down tilt bed-rest

Objectives: Spaceflight back pain and intervertebral disc (IVD) herniations cause problems in astronauts. Purpose of this study was to assess changes in T2-relaxation-time through MRI measurements before and after head-down tilt bed-rest, a spaceflight analog. Methods: 8 men participated in the bed-rest study. Subjects remained in 6° head down tilt bed-rest in two campaigns of 21 days, and received a nutritional intervention (potassium bicarbonate 90 mmol/d) in a cross-over design. MRI measurements were performed 2 days before bed-rest, as well as one and five days after getting up. Image Segmentation and data analysis were conducted for the IVDs Th12/L1 to L5/S1. Results: 7 subjects, average age of 27.6 (SD 3.3) years, completed the study. Results showed a significant increase in T2-time in all IVDs (p < 0.001), more pronounced in the nucleus pulposus than in the annulus fibrosus (p<0.001). Oral potassium bicarbonate did not show an effect p=0.443). Pfirrmanngrade correlated with the T2-time (p<0.001). Conclusions: 6° head-down tilt bed-rest leads to a T2-time increase in lumbar IVDs. Oral potassium bicarbonate supplementation does not have an effect on IVD T2-time

Fully Automatic Localization and Segmentation of 3D Vertebral Bodies from CT/MR Images via a Learning-Based Method

In this paper, we address the problems of fully automatic localization and segmentation of 3D vertebral bodies from CT/MR images. We propose a learning-based, unified random forest regression and classification framework to tackle these two problems. More specifically, in the first stage, the localization of 3D vertebral bodies is solved with random forest regression where we aggregate the votes from a set of randomly sampled image patches to get a probability map of the center of a target vertebral body in a given image. The resultant probability map is then further regularized by Hidden Markov Model (HMM) to eliminate potential ambiguity caused by the neighboring vertebral bodies. The output from the first stage allows us to define a region of interest (ROI) for the segmentation step, where we use random forest classification to estimate the likelihood of a voxel in the ROI being foreground or background. The estimated likelihood is combined with the prior probability, which is learned from a set of training data, to get the posterior probability of the voxel. The segmentation of the target vertebral body is then done by a binary thresholding of the estimated probability. We evaluated the present approach on two openly available datasets: 1) 3D T2-weighted spine MR images from 23 patients and 2) 3D spine CT images from 10 patients. Taking manual segmentation as the ground truth (each MR image contains at least 7 vertebral bodies from T11 to L5 and each CT image contains 5 vertebral bodies from L1 to L5), we evaluated the present approach with leave-one-out experiments. Specifically, for the T2-weighted MR images, we achieved for localization a mean error of 1.6 mm, and for segmentation a mean Dice metric of 88.7% and a mean surface distance of 1.5 mm, respectively. For the CT images we achieved for localization a mean error of 1.9 mm, and for segmentation a mean Dice metric of 91.0% and a mean surface distance of 0.9 mm, respectively

Heart Failure Treatment in Integrated Care Models According to </n> 140 SGB V

Zusammenfassung Deutschlandweit werden uber 20.000 Patienten in integrierten Herzinsuffizienz-Versorgungsmodellen betreut (Bundesverband Niedergelassener Kardiologen, personliche Kommunikation, 16. Juli 2020). Durch eine damit einhergehende, leitliniengerechte Pharmakotherapie und regelma ss ige Kontrolluntersuchungen lasst sich die Lebensqualitat von herzinsuffizienten Patienten deutlich verbessern. Daruber hinaus lassen sich Krankenhauseinweisungen und daraus resultierend Kosten fur die Krankenversicherungen minimieren. Eine enge Kooperation (in einem Netzwerk) zwischen Klinikkardiologen, niedergelassenen Kardiologen und Hausarzten ermoglicht eine optimale Herzinsuffizienz-Behandlung in allen Herzinsuffizienz-Schweregraden. Integrierte Versorgungmodelle wie CorBene oder KardioExpert tragen dazu bei, neben einer optimalen Patientenbetreuung, wissenschaftliche Auswertungen vorzunehmen und harte Endpunkte wie Re-Hospitalisierung oder kardiovaskulare Mortalitat zu reduzieren. Das hier vorgestellte KHAD-Modell (Kolner Herzen Atmen durch) ist ein integriertes Versorgungsmodell in dem die aktuellen Leitlinienempfehlungen zur poststationaren Versorgung von Herzinsuffizienzpatienten in der Region Koln umgesetzt werden sollen. Fast allen Krankenkassen unterstutzen das Modell. Es nehmen alle Kolner Krankenhauser und einige der niedergelassenen Kolner Kardiologen teil, um eine optimale Herzinsuffizienz-Versorgung gewahrleisten zu konnen. Solche Modelle fur eine Herzinsuffizienz-Betreuung konnten in allen deutschen Gro ss stadten praktiziert werden. Zum Wohle der Patienten, zur Einsparung von Potenzialen bei den Krankenkassen, fur eine angemessene Honorierung der behandelnden Arzte und zur Entlastung der Krankenhauser - ein Gewinn fur unsere Patienten und alle Beteiligten im Gesundheitssystem. Abstract Across Germany, more than 20,000 patients are cared for in integrated heart failure care models (Federal Association of General Practitioners of Cardiology, personal communication, 16 July 2020). The quality of life of patients with heart failure can be significantly improved by means of pharmacotherapy in accordance with guidelines and regular check-ups. In addition, hospital admissions and the resulting costs for health insurance companies can be minimised. Close cooperation (in a network) between clinical cardiologists, cardiologists in private practice and general practitioners enables optimal heart failure treatment in all degrees of heart failure. Integrated care models such as CorBene or KardioExpert contribute to optimal patient care, scientific evaluations and the reduction of hard endpoints such as re-hospitalisation or cardiovascular mortality. The KHAD model Kolner Herzen Atmen durch presented here is an integrated care model in which the current guidline recommendations for post-inpatient care of heart failure patients in the Cologne region are implemented. The model is supported by almost all health insurance companies. All Cologne hospitals and some of the Cologne cardiologists in private practice participate in order to ensure optimal heart failure care. Such models for heart failure care could be practised in all major German cities. For the benefit of the patients, for saving potential with the health insurance companies, for an appropriate remuneration of the attending physicians and to relieve the hospitals - a benefit for our patients and all those involved in the health system

Whey protein supplementation with vibration exercise ameliorates lumbar paraspinal muscle atrophy in prolonged bed rest

Optimizing countermeasures for musculoskeletal deterioration during spaceflight is a priority for space agencies. We examined the impact of adding whey protein supplementation to resistive vibration exercise (RVE) on lumbar deconditioning during prolonged bed rest. Participants (n = 12) were enrolled in a crossover design study of 21 days of bed rest with RVE (2 days/wk, 2-4 min/session time under tension), whey protein supplementation plus RVE (NeX), and no-intervention control (CNT). After bed rest, NeX [-2.2 (7.0)%, P = 0.370], but not RVE [-5.6 (6.4)%, P = 0.0027], reduced paraspinal muscle atrophy compared with CNT [-6.1 (5.5)%, P = 0.00035]. After 3 days of bed rest, whole intervertebral disk (IVD) T2 increased in all groups [CNT: +5.3 (2.5)%, P < 0.0001; NeX: +6.3 (1.8)%, P < 0.0001; RVE: +6.3 (1.9)%, P < 0.0001] and remained at this level on day 21 of bed rest [CNT: 5.5 (2.6)%, P < 0.0001; NeX: 6.0 (1.8)%, P < 0.0001; RVE: 6.2 (2.8)%, P < 0.0001]. Increases in IVD T2 were greatest in the nucleus [10.9 (1.1)%, P < 0.0001], with reductions of T2 observed in the anterior annulus [-4.4 (1.0) %, P = 0.00001] and increases in the posterior annulus [2.1 (0.8)%, P = 0.011]. At 6 and 28 days post-bed rest, IVD T2 was similar compared with baseline for all groups. A similar pattern was seen for IVD height, although a -3.8 (4.6)% (P = 0.0052) reduction of IVD height was seen 28 days after bed rest in the CNT group. The countermeasures did not impact on the presence or intensity of back pain during or after bed rest. Participants reporting back pain on day 3 of bed rest had greater (P = 0.013) increases in intervertebral disk volume than participants who did not. Although neither countermeasure impacted IVD changes or back pain in prolonged bed rest, NeX, but not RVE alone, ameliorated paraspinal muscle atrophy.NEW & NOTEWORTHY We examined the impact of adding protein supplementation to exercise (resistive vibration exercise) as a countermeasure against changes in the spine during spaceflight simulation. We found that adding the protein supplementation reduced spine muscle atrophy more than exercise alone. Neither countermeasure approach prevented changes in the disks in the spine or impacted back pain reports

Localization and Segmentation of 3D Intervertebral Discs in MR Images by Data Driven Estimation

This paper addresses the problem of fully-automatic localization and segmentation of 3D intervertebral discs (IVDs) from MR images. Our method contains two steps, where we first localize the center of each IVD, and then segment IVDs by classifying image pixels around each disc center as foreground (disc) or background. The disc localization is done by estimating the image displacements from a set of randomly sampled 3D image patches to the disc center. The image displacements are estimated by jointly optimizing the training and test displacement values in a data-driven way, where we take into consideration both the training data and the geometric constraint on the test image. After the disc centers are localized, we segment the discs by classifying image pixels around disc centers as background or foreground. The classification is done in a similar data-driven approach as we used for localization, but in this segmentation case we are aiming to estimate the foreground/background probability of each pixel instead of the image displacements. In addition, an extra neighborhood smooth constraint is introduced to enforce the local smoothness of the label field. Our method is validated on 3D T2-weighted turbo spin echo MR images of 35 patients from two different studies. Experiments show that compared to state of the art, our method achieves better or comparable results. Specifically, we achieve for localization a mean error of 1.6-2.0 mm, and for segmentation a mean Dice metric of 85%-88% and a mean surface distance of 1.3-1.4 mm

Initial estimation of the VB centers on one test CT image.

<p>The estimation is done in a coarse resolution. The response volume of L3, L4, and L5 are visualized in each row, with 3 randomly selected 2D sagittal slices. The diffused probability distribution is observed in the response volumes due to the repetitive pattern of the VBs.</p