Magnetic Resonance Elastography of Nucleus Pulposus Shear Modulus: A New Approach for Disc Degeneration Biomarkers

2012 ◽  
Author(s):  
Daniel H. Cortes ◽  
Jeremy F. Magland ◽  
Alexander C. Wright ◽  
Victor H. Barocas ◽  
Dawn M. Elliott
Keyword(s):  
Magnetic Resonance ◽  
Early Diagnosis ◽  
Shear Modulus ◽  
Disc Degeneration ◽  
Intervertebral Disc Degeneration ◽  
Structural Changes ◽  
Morphological Changes ◽  
Mr Images ◽  
New Approach ◽  
Advanced Stages

Intervertebral disc degeneration is cell mediated cascade of biochemical, mechanical and structural changes that disrupts its function. These changes are difficult to overturn; consequently, early diagnosis is key for the success of any treatment. Clinically, disc degeneration is diagnosed by the interpretation of morphological changes observed in T2 weighted MR images. However, those changes in morphology are characteristic of moderate to advanced stages of degeneration. Therefore, this method is not useful to diagnose early stages of disc degeneration.

Magnetic Resonance Elastography for the Measurement of Annulus Fibrosus Material Properties

2011 ◽  
Author(s):  
Daniel H. Cortes ◽  
Lachlan J. Smith ◽  
Sung M. Moon ◽  
Jeremy F. Magland ◽  
Alexander C. Wright ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Magnetic Resonance ◽  
Shear Modulus ◽  
Disc Degeneration ◽  
Annulus Fibrosus ◽  
Pulse Sequence ◽  
Imaging Techniques ◽  
Mechanical Vibration ◽  
Magnetic Resonance Elastography

Intervertebral disc degeneration is characterized by a progressive cascade of structural, biochemical and biomechanical changes affecting the annulus fibrosus (AF), nucleus pulposus (NP) and end plates (EP). These changes are considered to contribute to the onset of back pain. It has been shown that mechanical properties of the AF and NP change significantly with degeneration [1,2]. Therefore, mechanical properties have the potential to serve as a biomarker for diagnosis of disc degeneration. Currently, disc degeneration is diagnosed based on the detection of structural and compositional changes using MRI, X-ray, discography and other imaging techniques. These methods, however, do not measure directly the mechanical properties of the extracellular matrix of the disc. Magnetic Resonance Elastography (MRE) is a technique that has been used to measure in vivo mechanical properties of soft tissue by applying a mechanical vibration and measuring displacements with a motion-sensitized MRI pulse sequence [3]. The mechanical properties (e.g., the shear modulus) are calculated from the displacement field using an inverse method. Since the applied displacements are in the order of few microns, fibers may not be stretched enough to remove crimping. Therefore, it is unknown if the anisotropy of the AF due to the contribution of the fibers is detectable using MRE. The objective of this study is twofold: to measure shear properties of AF in different orientations to determine the degree of AF anisotropy observable by MRE, and to identify the contribution of different AF constituents to the measured shear modulus by applying different biochemical treatments.

Alterations in intramuscular water movement associated with mechanical changes in human skeletal muscle fibers: an evaluation using magnetic resonance diffusion-weighted imaging and B-mode ultrasonography

2011 ◽  
Vol 52 (9) ◽  
pp. 1003-1008 ◽  
Author(s):  
Osamu Yanagisawa ◽  
Toshiyuki Kurihara ◽  
Toru Fukubayashi
Keyword(s):  
Magnetic Resonance ◽  
Ankle Joint ◽  
Structural Changes ◽  
Water Movement ◽  
Morphological Changes ◽  
Muscle Fibers ◽  
Medial Gastrocnemius ◽  
Plantar Flexors ◽  
Diffusion Weighted Images ◽  
Diffusion Weighted

Background Intramuscular water movement is expected to be affected by the mechanical changes of the muscle fibers. However, the effect of changes in fiber length (FL) and pennation angle (PA) on the water movement has not been sufficiently investigated in human skeletal muscles. Purpose To determine the relationship between intramuscular water movement and the mechanical changes in human muscle fibers. Material and Methods Axial magnetic resonance diffusion-weighted images of the right leg (eight men) were taken using a 1.5-Tesla device with the ankle joint maximally dorsiflexed and maximally plantar flexed. The apparent diffusion coefficient (ADC) values of both the dorsiflexors (the superficial and deep parts of the tibialis anterior) and the plantar flexors (medial gastrocnemius and soleus) were calculated along three orthogonal axes (S-I: superior-to-inferior, A-P: anterior-to-posterior, and R-L: right-to-left). FL and PA of both muscle groups were also calculated from longitudinal B-mode ultrasound images with the ankle joint maximally dorsiflexed and plantar flexed. Results There was a significant increase in the ADC in superficial ( P < 0.05) and deeP ( P < 0.05) parts of the dorsiflexors in the S-I direction when the ankle was plantar flexed and in the A-P and R-L directions when the ankle was dorsiflexed ( P < 0.05). The plantar flexors showed significantly elevated ADC in the S-I direction when the ankle was dorsiflexed ( P < 0.05), and in the A-P and R-L directions when the ankle was plantar flexed ( P < 0.05). The dorsiflexors also showed significantly increased PA and decreased FL values when the ankle was dorsiflexed ( P < 0.05). The plantar flexors displayed similar morphological changes when the ankle was plantar flexed ( P < 0.05). Conclusion Water diffusion is affected by structural changes in the long axis of the muscle fibers, namely the changes in PA and FL.

scholarly journals T1ρ Magnetic Resonance Imaging Quantification of Early Lumbar Intervertebral Disc Degeneration in Healthy Young Adults

Spine ◽  
2012 ◽  
Vol 37 (14) ◽  
pp. 1224-1230 ◽  
Author(s):  
Bruno Beomonte Zobel ◽  
Gianluca Vadalà ◽  
Riccardo Del Vescovo ◽  
Sofia Battisti ◽  
Francesca Maria Martina ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Young Adults ◽  
Magnetic Resonance ◽  
Intervertebral Disc ◽  
Disc Degeneration ◽  
Intervertebral Disc Degeneration ◽  
Resonance Imaging ◽  
Lumbar Intervertebral Disc

scholarly journals Sequential MR Images and Radiographs of Epiphyseal Osteomyelitis in the Distal Femur of an Infant

2013 ◽  
Vol 2013 ◽  
pp. 1-4
Author(s):  
Hitomi Hara ◽  
Toshihiro Akisue ◽  
Teruya Kawamoto ◽  
Masahiro Kurosaka
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Early Diagnosis ◽  
Early Phase ◽  
Therapeutic Response ◽  
Distal Femur ◽  
Acute Osteomyelitis ◽  
Resonance Imaging ◽  
Mr Images ◽  
Magnetic Resonance Imaging Mri

Magnetic resonance imaging (MRI) plays an important role in the diagnosis of osteomyelitis, especially during the early phase of the disease. The findings of sequential MRIs during the course of treatment in acute osteomyelitis in children have not yet been reported in the literature. We present a case of acute epiphyseal osteomyelitis in the distal femur of an infant. We monitored imaging changes by sequential MRIs and radiographs. MRI was more useful than radiograph for early diagnosis and evaluation of therapeutic response.

scholarly journals Follistatin-Like 1 Attenuation Suppresses Intervertebral Disc Degeneration in Mice through Interacting with TNF-α and Smad Signaling Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Shaoyi Wang ◽  
Jianlu Wei ◽  
Jie Shi ◽  
Qiting He ◽  
Xiaocong Zhou ◽  
...  
Keyword(s):  
Intervertebral Disc ◽  
Disc Degeneration ◽  
Intervertebral Disc Degeneration ◽  
Inflammatory Diseases ◽  
Morphological Changes ◽  
Intervertebral Discs ◽  
Inflammatory Factors ◽  
Wild Type ◽  
Tnf Α

Background. Inflammation plays an important role in intervertebral disc degeneration (IDD). The protein follistatin-like 1 (FSTL1) plays a proinflammatory role in a variety of inflammatory diseases. Objectives. The purpose of this study was to investigate whether IDD could be delayed by inhibiting FSTL-1 expression. Methods. We established a puncture-induced IDD model in wild-type and FSTL-1+/- mice and collected intervertebral discs (IVDs) from the mice. Safranin O staining was used to detect cartilage loss of IVD tissue, and HE staining was used to detect morphological changes of IVD tissue. We measured the expression of FSTL-1 and related inflammatory indicators in IVD tissues by immunohistochemical staining, real-time PCR, and Western blotting. Results. In the age-induced model of IDD, the level of FSTL-1 increased with the exacerbation of degeneration. In the puncture-induced IDD model, FSTL-1-knockdown mice showed a reduced degree of degeneration compared with that of wild-type mice. Further experiments showed that FSTL-1 knockdown also significantly reduced the level of related inflammatory factors in IVD. In vitro experiments showed that FSTL-1 knockdown significantly reduced TNF-α-induced inflammation. Specifically, the expression levels of the inflammatory factors COX-2, iNOS, MMP-13, and ADAMTS-5 were reduced. Knockdown of FSTL-1 attenuated inflammation by inhibiting the expression of P-Smad1/5/8, P-Erk1/2, and P-P65. Conclusion. Knockdown of FSTL-1 attenuated inflammation by inhibiting the TNF-α response and Smad pathway activity and ultimately delayed IDD.

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