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Intervertebral Disc
Published in Manoj Ramachandran, Tom Nunn, Basic Orthopaedic Sciences, 2018
Will Aston, Alexander Montgomery, Rajiv Bajekal
A normal disc has a high signal on T2-weighted imaging in the nucleus. The signal characteristics of the disc in T2-weighted MRIs reflect changes caused by aging or degeneration. The brightness of the nucleus has been shown to correlate directly with the proteoglycan concentration, but not with the water or collagen. Other MRI findings associated with degeneration include disc space narrowing, herniation, stenosis, facet hypertrophy and ligamentum buckling, rotational changes on axial views (indicating possible scoliosis) and scoliosis on coronal views. Changes in the signal intensity of the adjacent vertebral body marrow are described as Modic changes.
The back
Published in Ashley W. Blom, David Warwick, Michael R. Whitehouse, Apley and Solomon’s System of Orthopaedics and Trauma, 2017
MRI findings include annular fissures, Modic changes (subchondral changes thought to be degenerative — Figure 18.31), disc degeneration and disc herniation. Modic changes are found in 46% of patients with non-specific low back pain (LBP) and 6% in the asymptomatic general population. Type 1 Modic changes have been linked to Propionibacterium acnes and Corynebacterium propinquum low-grade infections. This remains contentious and research continues into the condition. Most patients with proven disc pathology will not have Modic changes. As diagnostic markers, Modic signs have relatively low sensitivity.
Animal Models and Imaging of Intervertebral Disc Degeneration
Published in Raquel M. Gonçalves, Mário Adolfo Barbosa, Gene and Cell Delivery for Intervertebral Disc Degeneration, 2018
Marion Fusellier, Johann Clouet, Olivier Gauthier, Catherine Le Visage, Jerome Guicheux
A semiquantitative evaluation of IVD degeneration is possible with the Pfirrmann five-level grading sometimes modified by increasing the number of grades from five to eight (Griffith et al. 2007). The Pfirrmann grading scale provides a reliable and reproducible evaluation of DDD on T2w images and is based on MRI signs: disc signal intensity, differentiation of AF and NP, and IVD height that demonstrated sufficient intraobserver and interobserver correlation (Pfirrmann et al. 2001b). In grade I, the disc structure is homogeneous with a net hypersignal of the NP and a normal disc height. In grade II, the disc structure becomes heterogeneous, with a slightly less intense hypersignal of the NP. The distinction between AF and NP is possible with a normal disc height and with or without a horizontal gray band. Lowering the T2 signal is thought to reflect a diminished GAG concentration in the IVD (Johannessen et al. 2006; Weidenbaum et al. 1992). In grade III, the IVD structure is heterogeneous with an intermediate signal. The distinction between AF and NP is not very clear and the IVD height is normal or slightly decreased. In grade IV, the IVD structure is heterogeneous with a marked hypointense signal. There is a complete loss of distinction between AF and NP and normal or decreased IVD height. Finally in grade V, the IVD structure is heterogeneous, with a deep hypointense signal and complete loss of a distinction between AF and NP, and IVD collapse starts to be detectable. This grading system is now largely used in all the studies related to disc degeneration (Bergknut et al. 2012; Clouet et al. 2011; Ohnishi et al. 2016; Omlor et al. 2009; Zhou et al. 2007), sometimes in association with the classification of Modic to better characterize degenerative discopathies. Associated with changes on the disc, modification of the adjacent structures can be observed: Modic described three types of endplate changes on MRI depending on the underlying bone marrow signal (De Roos et al. 1987; Modic et al. 1988). Type I Modic changes lead to T1w hypointense and T2w hyperintense endplate, probably because of an acute reaction of the bone marrow with replacement of the hematopoietic bone marrow by vascularized fibrous tissue (Table 2.3). Type II Modic changes are an increased signal on T1w and isointense to hyperintense signal on T2w because of the presence of fat marrow. Modic type III changes are seen as T1w and T2w hypointense signals because of the presence of dense woven bone and absence of bone marrow.
Factors associated with the recurrence of lumbar disk herniation: non-biomechanical–radiological and intraoperative factors
Published in Neurological Research, 2023
Anas Abdallah, Betül Güler Abdallah
Preoperative dynamic, lateral, and standing anteroposterior radiographs, sagittal and axial T1-weighted (T1W), T2-weighted (T2W), short tau inversion recovery (STIR), T2-weighted fast spin-echo (T2-FSE) magnetic resonance images were obtained from all patients. Modic changes (MCs) were distinct on T1W and T2W images. STIR images were used to distinguish borderline MCs types I and II. Near iso-intense on T1W images were rated as type II. That is type I requires a clear hypointensity on T1W and hyperintensity on STIR images. Type II shows hypointensity on STIR images [8] (Figure 2). The presence of the annular fissure/defect was detected on T2W images [9,10]. Radiological disk shapes (protruded, extruded, or sequestered) were detected on axial and sagittal T2W images. T2-FSE images were used to determine the disk degeneration grade according to the Pfirrmann classification [11,12]. Regarding their structural radiological features, such as distinguishability of nucleus from annulus fibrosus, signal intensity, and disk height, Pfirrmann et al. classified the degeneration of the lumbar disks into separated five grades [12] (Figure 3).
Biomechanical comparison of vertebral augmentation and cement discoplasty for the treatment of symptomatic Schmorl’s node: a finite element analysis
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2022
Kaiwen Cai, Zhang Zhang, Kefeng Luo, Feng Cao, Bin Lu, Yuanhua Wu, Hongxia Wang, Kai Zhang, Guoqiang Jiang
Previous studies that have examined the use of PVA and PCD in LBP have consistently demonstrated superior results, relative to other methods. He et al. followed 11 patients with a symptomatic Schmorl’s node treated by PVP for an average of 58 months, and reported satisfactory long-term pain relief with no evidence of surgery-related complications (He et al. 2017). Zhi-Yong et al. reported 32 patients treated with PKP for whom VAS, ODI, and SF-36 scores exhibited significant improvements after surgery and were well maintained over a 5-year follow-up period (Zhi-Yong et al. 2017). Of these patients, only three cases (6.98%) of cement disc leakage and two cases (4.65%) of adjacent vertebral fracture (AVF) were observed. In addition, Tian et al. reported that PCD treatment for patients with LBP with Modic changes provided satisfactory outcomes, with no obvious surgical-related complications (Tian et al. 2017, 2019). Based on these observations, the promise of these two minimally invasive surgical treatments has been proven. However, the evidence each of these therapies is based on a small number of case series reports, with no randomized controlled trials used to validate these outcomes. Due to the lack of high-level evidence, the understanding of the benefits and potential risks of these two therapies is still unclear, and theoretical demonstration is still necessary.
Modic changes and its association with other MRI phenotypes in east Anatolian low back pain patients
Published in British Journal of Neurosurgery, 2022
Modic changes (MCs) represent a type of spinal phenotypic features and are evaluated using magnetic resonance imaging (MRI). The relationship between LBP and MCs has not yet been completely evaluated. Several studies have demonstrated a relationship between MCs and LBP4–7; however, conflicting findings that do not relate to pain have also been reported.8 Through a systemic review, Jensen et al. reported that MC changes have a mean prevalence of 43% in patients with LBP and an average prevalence of 6% in the nonclinical population.4 However, the relative prevalence of MCs among patients with LBP compared with controls differs between the European and the Far Eastern populations. This highlights the lack of information concerning the development of MCs. Genetic factors reportedly affect the development and severity of disc degeneration.9 Furthermore, polymorphisms in proteins belonging to the interleukin-1 family are reportedly associated with MCs.10,11 These results indicate the possibility of differences in the prevalence of MCs among ethnic groups. Although several studies have explored the prevalence of MCs among the Asian and European populations, the prevalence of MCs and their correlations with other phenotypic features in patients with chronic LBP have not previously been investigated in the Eastern Anatolian population.