Etude de l'épaisseur, de la complexité corticales et du gradient dans l'épilepsie partielle réfractaire associée à une dysplasie corticale focale

AMIENS-BU Santé (800212102) / SudocSudocFranceF

A cadaveric simulation-teaching model for radiology residents.

Place: EnglandInternational audienc

Intradiscal oxygen-ozone therapy for the treatment of symptomatic lumbar disc herniation: A preliminary study.

Place: FranceInternational audiencePURPOSE: To assess safety and effectiveness of computed tomography (CT)-guided intradiscal oxygen-ozone therapy (O(2)-O(3) therapy) for the treatment of symptomatic lumbar disc herniation and radiological changes. MATERIALS AND METHODS: This study was conducted in twenty patients presenting lumbar disc herniation with resistant lumbar or lumbar radicular pain They underwent intradiscal oxygen-ozone therapy under CT guidance. They were treated at one- or two-disc levels, representing a total of 24 discs treated. MR imaging examinations were obtained before treatment and 2 months post-procedure to analyse treatment-related disc modifications including modification of the surfaces of the disc and of the herniated disc, and the variations in disc height according to the disc height index. Clinical outcomes were assessed using the visual analogue scale (VAS) to evaluate the severity of pain before the procedure, at primary (2 months) and at secondary (12 months) follow-ups. RESULTS: All the procedures were technically successful. The median VAS scores were 7.95 before the procedure, 3.9 at 2 months and 2.95 at 12 months. MRI analysis showed a significant decrease in herniation size at 2 months (-20%, p = 0.008). No immediate or late complications were observed. Only three patients (13.6%) underwent lumbar spine microdiscectomy in the year following ozone therapy. The treatment appeared to be more effective in cases of nerve root symptomatology. CONCLUSION: This study suggests that intradiscal O(2)-O(3) therapy is safe and effective for the treatment of lumbar disc herniation associated with resistant lumbar or lumbar radicular pain

Posture‐related stiffness mapping of paraspinal muscles

International audienceThe paraspinal compartment acts as a bone–muscle composite beam of the spine. The elastic properties of theparaspinal muscles play a critical role in spine stabilization. These properties depend on the subjects’ posture, andthey may be drastically altered by low back pain. Supersonic shear wave elastography can be used to providequantitative stiffness maps (elastograms), which characterize the elastic properties of the probed tissue. The aimof this study was to challenge shear wave elastography sensitivity to postural stiffness changes in healthyparaspinal muscles. The stiffness of the main paraspinal muscles (longissimus, iliocostalis, multifidus) wasmeasured by shear wave elastography at the lumbosacral level (L3 and S1) for six static postures performed byvolunteers. Passive postures (rest, passive flexion, passive extension) were performed in a first shear waveelastography session, and active postures (upright, bending forward, bending backward) with rest posture forreference were performed in a second session. Measurements were repeated three times for each posture. Sixteenhealthy young adults were enrolled in the study. Non-parametric paired tests, multiple analyses of covariance, andintra-class correlations were implemented for analysis. Shear wave elastography showed good to excellentreliability, except in the multifidus at S1, during bending forward, and in the multifidus at L3, during bendingbackward. Yet, during bending forward, only poor quality was recorded for nine volunteers in the longissimus.Significant intra- and inter-muscular changes were observed with posture. Stiffness significantly increased for theupright position and bending forward with respect to the reference values recorded in passive postures. Inconclusion, shear wave elastography allows reliable assessment of the stiffness of the paraspinal muscles except inthe multifidus at S1 and longissimus, during bending forward, and in the multifidus at L3, during bendingbackward. It reveals a different biomechanical behaviour for the multifidus, the longissimus, and the iliocostalis

Texture Parameters Measured by UHF-MRI and CT Scan Provide Information on Bone Quality in Addition to BMD: A Biomechanical Ex Vivo Study

The current definition of osteoporosis includes alteration of bone quality. The assessment of bone quality is improved by the development of new texture analysis softwares. Our objectives were to assess if proximal femoral trabecular bone texture measured in Ultra high field (UHF) 7 Tesla MRI and CT scan were related to biomechanical parameters, and if the combination of texture parameters and areal bone mineral density (aBMD) measured by dual-energy X-ray absorptiometry provided a better prediction of femoral failure than aBMD alone. The aBMD of 16 proximal femur ends from eight cadavers were investigated. Nineteen textural parameters were computed in three regions or volumes of interest for each specimen on UHF MRI and CT scan. Then, the corresponding failure load and failure stress were calculated thanks to mechanical compression test. aBMD was not correlated to failure load (R-2 = 0.206) and stress (R-2 = 0.153). The failure load was significantly correlated with ten parameters in the greater trochanter using UHF MRI, and with one parameter in the neck and the greater trochanter using CT scan. Eight parameters in the greater trochanter using UHF MRI combined with aBMD improved the failure load prediction, and seven parameters improved the failure stress prediction. Our results suggest that textural parameters provide additional information on the fracture risk of the proximal femur when aBMD is not contributive

Texture Parameters Measured by UHF-MRI and CT Scan Provide Information on Bone Quality in Addition to BMD: A Biomechanical Ex Vivo Study

The current definition of osteoporosis includes alteration of bone quality. The assessment of bone quality is improved by the development of new texture analysis softwares. Our objectives were to assess if proximal femoral trabecular bone texture measured in Ultra high field (UHF) 7 Tesla MRI and CT scan were related to biomechanical parameters, and if the combination of texture parameters and areal bone mineral density (aBMD) measured by dual-energy X-ray absorptiometry provided a better prediction of femoral failure than aBMD alone. The aBMD of 16 proximal femur ends from eight cadavers were investigated. Nineteen textural parameters were computed in three regions or volumes of interest for each specimen on UHF MRI and CT scan. Then, the corresponding failure load and failure stress were calculated thanks to mechanical compression test. aBMD was not correlated to failure load (R-2 = 0.206) and stress (R-2 = 0.153). The failure load was significantly correlated with ten parameters in the greater trochanter using UHF MRI, and with one parameter in the neck and the greater trochanter using CT scan. Eight parameters in the greater trochanter using UHF MRI combined with aBMD improved the failure load prediction, and seven parameters improved the failure stress prediction. Our results suggest that textural parameters provide additional information on the fracture risk of the proximal femur when aBMD is not contributive

Abdominal musculature segmentation and surface prediction from CT using deep learning for sarcopenia assessment

International audiencePurpose :The purpose of this study was to build and train a deep convolutional neural networks (CNN) algorithm to segment muscular body mass (MBM) to predict muscular surface from a two-dimensional axial computed tomography (CT) slice through L3 vertebra.Materials and methods :An ensemble of 15 deep learning models with a two-dimensional U-net architecture with a 4-level depth and 18 initial filters were trained to segment MBM. The muscular surface values were computed from the predicted masks and corrected with the algorithm's estimated bias. Resulting mask prediction and surface prediction were assessed using Dice similarity coefficient (DSC) and root mean squared error (RMSE) scores respectively using ground truth masks as standards of reference.Results :A total of 1025 individual CT slices were used for training and validation and 500 additional axial CT slices were used for testing. The obtained mean DSC and RMSE on the test set were 0.97 and 3.7 cm2 respectively.Conclusion :Deep learning methods using convolutional neural networks algorithm enable a robust and automated extraction of CT derived MBM for sarcopenia assessment, which could be implemented in a clinical workflow