scholarly journals Correlation between magnetic resonance, X-ray imaging alterations and histological changes in an ovine model of age-related disc degeneration

2021 ◽  
Vol 42 ◽  
pp. 166-178
Author(s):  
N Bouhsina ◽  
◽  
C Decante ◽  
JB Hardel ◽  
S Madec ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Disc Degeneration ◽  
Disc Height ◽  
Strongly Correlated ◽  
X Ray ◽  
Age Related ◽  
Magnetic Resonance Imaging Mri ◽  
The Many ◽  
Tissue Alterations ◽  
Ivd Degeneration

Sheep are one of the many animal models used to investigate the pathophysiology of disc degeneration and the regenerative strategies for intervertebral disc (IVD) disease. To date, few studies have thoroughly explored ageing of ovine lumbar IVDs. Hence, the objective of the present study was to concomitantly assess the development of spontaneous age-related lumbar IVD degeneration in sheep using X-ray, magnetic resonance imaging (MRI) as well as histological analyses. 8 young ewes (< 48 months old) and 4 skeletally mature ewes (> 48 months old) were included. Disc height, Pfirrmann and modified Pfirrmann grades as well as T2-wsi and T2 times were assessed by X-ray and MRI. The modified Boos score was also determined using histology sections. Pfirrmann (2 to 3) and modified Pfirrmann (2 to 4) grades as well as Boos scores (7 to 13) gradually increased with ageing, while T2-weighted signal intensity (1.18 to 0.75), T2 relaxation time (114.36 to 70.65 ms) and disc height (4.1 to 3.2 mm) decreased significantly. All the imaging modalities strongly correlated with the histology (p < 0.0001). The present study described the suitability of sheep as a model of age-related IVD degeneration by correlation of histological tissue alterations with the changes observed using X-ray and MRI. Given the structural similarities with humans, the study demonstrated that sheep warrant being considered as a pertinent animal model to investigate IVD regenerative strategies without induction of degeneration.

scholarly journals Denosumab Alleviates Intervertebral Disc Degeneration Adjacent to a Lumbar Fusion by Inhibiting Endplate Osteochondral Remodeling and Vertebral Osteoporosis in Ovariectomized Rats

2020 ◽  
Author(s):  
Qi Sun ◽  
Fa-Ming Tian ◽  
Fang Liu ◽  
Jia-Kang Fang ◽  
Yun-Peng Hu ◽  
...  
Keyword(s):  
Bone Formation ◽  
Intervertebral Disc ◽  
Disc Degeneration ◽  
Intervertebral Disc Degeneration ◽  
Lumbar Fusion ◽  
Biomechanical Properties ◽  
Disc Height ◽  
X Ray ◽  
Manual Palpation ◽  
Trap Staining

Abstract Background: Although adjacent segmental intervertebral disc degeneration (ASDD) is one of the most common complications after lumbar fusion, its exact mechanism remains unclear. As an antibody to RANKL, denosumab (Dmab) effectively reduces bone resorption and stimulates bone formation, which can increase bone mineral density (BMD) and improve osteoporosis. However, it has not been confirmed whether Dmab has a reversing or retarding effect on ASDD. Methods: Three-month-old female Sprague-Dawley rats that underwent L4–L5 posterolateral lumbar fusion (PLF) with spinous-process wire fixation four weeks after OVX surgery were given Dmab four weeks after PLF surgery (OVX+PLF+Dmab group). In addition, the following control groups were defined: Sham, OVX, PLF, and OVX+PLF (n=12 each).Then, manual palpation and X-ray were used to evaluate the state of lumbar fusion. The bone microstructure in the lumbar vertebra and endplate as well as the disc height index (DHI) of the L5/6 were evaluated by microcomputed tomography (μCT). The characteristic alterations of ASDD were identified via Safranin-O green staining staining. Osteoclasts were detected using tartrate-resistant acid phosphatase (TRAP) staining and the biomechanical properties of vertebra were evaluated. Aggrecan (Agg), metalloproteinase-13 (MMP-13), a disintegrin and metalloproteinase with thrombospondin motifs 4 (ADAMTS-4) expression in the intervertebral disc were detected by immunohistochemistry and real-time polymerase chain reaction (RT-PCR) analysis.Results: Manual palpation showed clear evidence of the fused segment’s immobility. Compared to the OVX+PLF group, more new bone formation was observed by X-ray examination in the OVX+PLF+Dmab group. Dmab significantly alleviated ASDD by retaining disc height index (DHI), decreasing porosity of endplate, and increasing the biomechanical properties and BMD of vertebra. TRAP staining results showed a significantly decreased number after Dmab treatment, especially in subchondral bone and cartilaginous endplate. Moreover, the results of protein and mRNA expression in intervertebral disc (IVD) showed that Dmab not only inhibited matrix degradation by decreasing MMP-13 and ADAMTS-4 but also promoted matrix synthesis by increasing Agg. Conclusions: These results suggest that Dmab may be a novel therapeutic target for the treatment of ASDD.

Steerable Guidewire for Magnetic Resonance Guided Endovascular Interventions

2014 ◽  
Vol 8 (2) ◽  
Author(s):  
H. C. M. Clogenson ◽  
J. Dankelman ◽  
J. J. van den Dobbelsteen
Keyword(s):  
Magnetic Resonance ◽  
Vascular System ◽  
Proof Of Concept ◽  
X Ray ◽  
Endovascular Interventions ◽  
Tissue Contrast ◽  
Current Design ◽  
Magnetic Resonance Imaging Mri ◽  
To Come ◽  
Flexible Instruments

In endovascular interventions, thin, flexible instruments are inserted through the skin into the blood vessels to diagnose and treat various diseases of the vascular system. One drawback is that the instruments are difficult to maneuver in the desired direction due to limitations in shape and flexibility. Another disadvantage is that the interventions are performed under intermittent fluoroscopy/angiography imaging. Magnetic resonance imaging (MRI) may offer advantages over X-ray guidance. It presents a good soft tissue contrast without the use of nephrotoxic media or ionizing radiation. The aim of this study is to develop a guidewire that is compatible with MRI and includes a steerable segment at the tip. This added degree-of-freedom may improve the maneuverability of the devices thereby the efficiently and safety of the navigation. A 1.6 m (5 ft, 3 in.) long and 0.035 in. diameter guidewire that consists of MR compatible materials and has a flexible tip was designed. The only metallic part was a nitinol rod that was implemented at the distal flexible tip. To limit the risk of heating in the MRI, this rod was kept shorter than 30 mm. The tip could be deflected in one direction by pulling on a Dyneema wire that was placed in the lumen of the shaft of the guidewire. To drive the steerable tip, a handle that could be easily attached/detached from the instrument was designed and implemented. Using the handle, the tip of the 1.60 m long guidewire prototype could be actuated to reach angles from 30 deg to 250 deg. The handle could easily be placed on and removed from the guidewire, so conventional 0.035 in.–compatible catheters could slide over from the proximal end. However, in order to make the guidewire more efficient to enter a bifurcation, the stiffness of the tip should progressively increase from its proximal to its distal end. The guidewire was imaged in a 1.5T MRI using real-time imaging without producing artifacts that would have shaded the anatomy. It was possible to assemble a guidewire with a steerable segment in the required size, using MR compatible materials. Therefore, the current design is a promising proof of concept and allowed us to clearly identify the features that need to be improved in order to come to a clinically applicable instrument.

scholarly journals Relationship between Echocardiographic and Magnetic Resonance-Derived Measurements of the Thoracic Aorta in Turner Syndrome Patients

2019 ◽  
Vol 2019 ◽  
pp. 1-6
Author(s):  
Rūta Krikščiūnienė ◽  
Inesa Navickaitė ◽  
Eglė Ereminienė ◽  
Saulius Lukoševičius ◽  
Birutė Žilaitienė ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Turner Syndrome ◽  
Cardiovascular Complications ◽  
Cross Sectional Study ◽  
Ascending Aorta ◽  
Strongly Correlated ◽  
Aortic Sinus ◽  
Cross Sectional ◽  
Magnetic Resonance Imaging Mri ◽  
Aortic Size

Introduction. Turner syndrome (TS) is assigned to the rare diseases group. Morbidity and mortality of TS patients are high, particularly due to the cardiovascular disorders, so monitoring for cardiovascular complications must be ensured. The data demonstrate a strong correlation between 2-dimensional echocardiographic (2Decho) evaluation and magnetic resonance imaging (MRI); still, according to recent guidelines, MRI remains a gold standard. In this study, we aimed to compare aortic dimensions on MRI and 2Decho in TS patients. Methods. 50 TS patients (≥18 years) were enrolled into the cross-sectional study. 2Decho and MRI were performed. The measurements of the aorta were assessed in five standard positions on 2Decho and in 9 standard positions on MRI; ASI (aortic size index) of the ascending aorta was calculated since reduced adult height is observed in TS patients. Results. ASI on echocardiography strongly correlated with ASI on MRI in all positions of the ascending aorta, but significantly larger medians of ASI were found on 2Decho in all positions of the ascending aorta and arch when compared with MRI measurements. Still, the prevalence of aortic sinus dilation was significantly and more frequently (52% vs. 38%, p<0.001) observed on MRI when compared with 2Decho. Conclusion. The relation of aortic size was significant in all positions when comparing the MRI and 2Decho methods; still, the dilatation of the sinus of aorta was more frequently found on MRI compared with echocardiography.

A porcine model of intervertebral disc degeneration induced by annular injury characterized with magnetic resonance imaging and histopathological findings

2008 ◽  
Vol 8 (5) ◽  
pp. 450-457 ◽  
Author(s):  
Seung-Hwan Yoon ◽  
Masashi Miyazaki ◽  
Soon-Woo Hong ◽  
Ben Tow ◽  
Yuichiro Morishita ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Mr Imaging ◽  
Disc Degeneration ◽  
Annulus Fibrosus ◽  
Porcine Model ◽  
Disc Height ◽  
Final Time ◽  
Progressive Degeneration ◽  
Final Time Point ◽  
Time Point

Object Appropriate animal models of disc degeneration are critical for the study of proposed interventions as well as to further delineate the degenerative process. The purpose of this study was to characterize a porcine model for disc degeneration confirmed on magnetic resonance (MR) imaging studies and histological analysis. Methods Twelve miniature pigs were used (weight 48–65 kg) to study degeneration in the lumbar spine. Under fluoroscopic guidance, the disc was percutaneously punctured with a 3.2-mm-diameter trephine to a 5-mm depth into the annulus fibrosus. Control and experimental levels were randomized among 6 levels in the lumbar spine. The unlesioned spinal levels were used as controls and were compared with lesioned levels. Magnetic resonance imaging grading and disc height were serially recorded preoperatively, and at 5, 8, 19, 32, and 39 weeks postoperatively. The animals were killed in groups of 3 at 7, 18, 32, and 41 weeks postinjury, and the discs were examined histopathologically. Results Consistent, sequential, and progressive degeneration of the annular injury was observed on MR imaging and histopathological studies from the time of injury to the final time point. The disc height and the disc height index also sequentially decreased from the time of the injury in a consistent manner. The uninjured control levels did not show any progressive degeneration and maintained their normal state. Conclusions Based on MR imaging and histopathological findings, the authors demonstrated and characterized a reliable model of sequential disc degeneration in miniature pigs with percutaneous injury to the annulus fibrosus. In the early stages, as soon as 5 weeks after injury, significant disc degeneration was seen on MR imaging grading with decreases in disc height. This degeneration did not improve by the final time point of 39 weeks.

scholarly journals A Clinical Prospective Observational Cohort Study on the Prevalence and Primary Diagnostic Accuracy of Occult Vertebral Fractures in Aged Women with Acute Lower Back Pain Using Magnetic Resonance Imaging

2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Atsushi Terakado ◽  
Sumihisa Orita ◽  
Kazuhide Inage ◽  
Go Kubota ◽  
Tomohiro Kanzaki ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Back Pain ◽  
Magnetic Resonance ◽  
Diagnostic Accuracy ◽  
Elderly Women ◽  
Resonance Imaging ◽  
Mineral Density ◽  
X Ray ◽  
Acute Low Back Pain ◽  
Magnetic Resonance Imaging Mri

Background.Elderly female patients complaints of acute low back pain (LBP) may involve vertebral fracture (VF), among which occult VF (OVF: early-stage VF without any morphological change) is often missed to be detected by primary X-ray examination. The current study aimed to investigate the prevalence of VF and OVF and the diagnostic accuracy of the initial X-ray in detecting OVF.Method.Subjects were elderly women (>70 years old) complaining of acute LBP with an accurate onset date. Subjects underwent lumbar X-ray, magnetic resonance imaging (MRI), and bone mineral density (BMD) measurement at their first visit. The distribution of radiological findings from X-ray and magnetic resonance imaging (MRI) as well as the calculation of the prevalence of VF and OVF are investigated.Results. The prevalence of VF among elderly women with LBP was 76.5% and L1 was the most commonly injured level. Among VF cases, the prevalence of OVF was 33.3%. Furthermore, osteoporotic patients tend to show increased prevalence of VF (87.5%). The predictive values in detecting VF on the initial plain X-ray were as follows: sensitivity, 51.3%; specificity, 75.0%; and accuracy rate, 56.7%.Conclusions.Acute LBP patients may suffer vertebral injury with almost no morphologic change in X-ray, which can be detected using MRI.

Radiology

2014 ◽  
Author(s):  
Murray Longmore ◽  
Ian B. Wilkinson ◽  
Andrew Baldwin ◽  
Elizabeth Wallin
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Magnetic Resonance ◽  
Ionizing Radiation ◽  
Resonance Imaging ◽  
X Ray ◽  
Chest X Ray ◽  
Effective Doses ◽  
Magnetic Resonance Imaging Mri

Principles in radiology:Typical effective dosesJustifying exposure to ionizing radiationThe art of the requestInterpreting an imagePresenting an imageModalities:Chest x-ray (cxr) –740Plain abdominal x-rayComputed tomography (ct) –746Magnetic resonance imaging (mri...

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