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Purpose: Although signal intensity on T2W axial images is sensitive in detection of fatty infiltration to assess paraspinal muscle degeneration, it is affected by inhomogeneities of magnetic fields and individual variabilities. The purpose of this study was to propose reference adjusted signal measures on T2W axial images and determine their capacities in reflecting age-related lumbar paraspinal muscle degeneration. Methods: Lumbar MR images of 421 population-based subjects (177 men and 244 women, mean age 53.1 years, range 19.8–87.9 years) were studied. A custom software Spine Explore (Tulong 2.0) was used to automatically obtain paraspinal measurements of multifidus, erector spinae and psoas major. FCSA/TCSA was defined as functional cross-sectional area relative to total cross-sectional area of paraspinal muscle. Two new signal measures were canal-adjusted and cerebrospinal fluid (CSF)-adjusted signal, defined as the ratio between mean signal measurements and the mean signal of the canal and CSF. Results: The raw signal measurements of the paraspinal muscles were weakly correlated to age (r = 0.28–0.39, P < 0.001). When the signal of canal (r = 0.43–0.59, P < 0.001) or CSF (r = 0.45–0.61, P < 0.001) was used as reference, the correlations substantially increased. Signal measurements of three paraspinal muscles, adjusted or not, were strongly associated with Goutallier score (ρ = 0.60–0.65, P < 0.001) and FCSA/TCSA (r = −0.64 to −0.82, P < 0.001). Greater Goutallier score was associated with greater age (r = 0.38–0.60, P < 0.001), while Lumbar indentation value (LIV) not. Conclusion: On routine T2W axial MR images the adjusted signal measurements using an internal reference of CSF or canal can better reflect age-related degenerative changes in the paraspinal muscles. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the role of gravity in the sedimentation of lumbar spine nerve roots using magnetic resonance (MR) imaging of various body positions.Methods: A total of 56 patients, who suffered from back pain and underwent conventional supine lumbar spine MR imaging, were selected from sanmen hospital database. All the patients were called back to our hospital to perform MR imaging in prone position or lateral position. Furthermore, the sedimentation sign (SedSign) was determined based on the suspension of the nerve roots in the dural sac on cross-sectional MR images, and 31 cases were rated as positive and another 25 cases were negative.Results: The mean age of negative SedSign group was significantly younger than that of positive SedSign group (51.7 ± 8.7 vs 68.4 ± 10.5, P < 0.05). The constitutions of clinical diagnosis were significantly different between patients with a positive SedSign and those with a negative SedSign (P < 0.001). Overall, nerve roots of the vast majority of patients (48/56, 85.7%) subsided to the ventral side of the dural sac on the prone MR images, although that of 8 (14.3%) patients remain stay in the dorsal side of dural sac. Nerve roots of only one patient with negative SedSign did not settle to the ventral dural sac, while this phenomenon occurred in 7 patients in positive SedSign group (4% vs 22.6%, P < 0.001). In addition, the nerve roots of all the five patients subsided to the left side of dural sac on lateral position MR images.Conclusions: The nerve roots sedimentation followed the direction of gravity. Positive SedSign may be a MR sign of lumbar pathology involved the spinal canal. [ABSTRACT FROM AUTHOR]

Study Design: A cross-sectional magnetic resonance (MR) imaging study.Objective: To classify and characterize endplate defects using routine lumbar MR images and to determine associations of endplate defects with Modic changes (MCs) and disc degeneration.Summary Of Background Data: Previously, a cadaveric study revealed that endplate lesions were common and associated with back pain history. New in vivo approaches appropriate for clinical studies are needed to further this potentially important line of research on the clinical significance of endplate lesions, including their relation with MCs, disc degeneration, and back pain.Methods: Using a MRI archive, 1564 endplates of 133 subjects (59 men and 74 women, mean age 58.9 ± 11.9 years) with the presence of MCs were retrospectively collected from April of 2014 to June of 2015. On the basis of morphological characteristics, a protocol was proposed to identify three distinct types of endplate defects, including focal, corner, and erosive defects. The location, size, and distribution patterns of various endplate lesions were characterized. MCs and disc degeneration were measured to examine their associations with endplate defects.Results: Endplate defects were observed in 27.8% of endplates studied. Greater age was associated with the presence of endplate defects. Focal defects were the most common (13.5%), followed by erosive defects (11.1%) and corner defects (3.2%). Defect types also differed in size and distribution patterns. Endplate defects and MCs had similar distribution patterns in the lumbar spine. The presence of endplate defects were associated with the presence of MCs (odds ratio = 4.29, P < 0.001), and associated with less disc signal intensity and disc height, and greater disc bulging (P < 0.05).Conclusion: The three endplate defects identified on routine MR images appear to represent different pathologies and may play a key role in the pathogenesis of MCs. This classification system may facilitate clinical studies on endplate defects.Level Of Evidence: 4. [ABSTRACT FROM AUTHOR]

Objectives: The integrity of endplate is important for maintaining the health of adjacent disc and trabeculae. Yet, pathological impacts of traumatic vertebra and endplate fractures were less studied using clinical approaches. This study aims to investigate their effects on the development of adjacent disc degeneration, segmental kyphosis, Modic changes (MCs), and high-intensity zones (HIZs). Materials and methods: Magnetic resonance (MR) images of patients with acute traumatic vertebral compression fractures (T11-L5) were studied. On MR images, endplate fractures were evaluated as present or absent. Disc signal, height, bulging area, sagittal Cobb angle, MCs, and HIZs were measured on baseline and follow-up MR images to study the changes of the disc in relation to vertebra fractures and endplate fractures. Results: Ninety-seven patients were followed up for 15.4 ± 14.0 months. There were 123 fractured vertebrae, including 79 (64.2%) with endplate fractures and 44 (35.8%) without. Both the adjacent and control discs decreased in signal and height over time (p < 0.001), and the disc adjacent to vertebral fractures had greater signal and height loss than the control disc (p < 0.05). In the presence of endplate fractures, the adjacent discs had greater signal decrease in follow-up (p < 0.05), as compared to those without endplate fractures. Sagittal Cobb angle significantly increased in segments with endplate fractures (p < 0.05). Vertebra fractures were associated with new occurrence of MCs in the fractured vertebra (p < 0.001) but not HIZs in the adjacent disc. Conclusions: Traumatic vertebral fractures were associated with accelerated adjacent disc degeneration, which appears to be further promoted by concomitant endplate fractures. Endplate fractures were associated with progression of segmental kyphosis. [ABSTRACT FROM AUTHOR]

Objectives: The integrity of endplate is important for maintaining the health of adjacent disc and trabeculae. Yet, pathological impacts of traumatic vertebra and endplate fractures were less studied using clinical approaches. This study aims to investigate their effects on the development of adjacent disc degeneration, segmental kyphosis, Modic changes (MCs), and high-intensity zones (HIZs). Materials and methods: Magnetic resonance (MR) images of patients with acute traumatic vertebral compression fractures (T11-L5) were studied. On MR images, endplate fractures were evaluated as present or absent. Disc signal, height, bulging area, sagittal Cobb angle, MCs, and HIZs were measured on baseline and follow-up MR images to study the changes of the disc in relation to vertebra fractures and endplate fractures. Results: Ninety-seven patients were followed up for 15.4 ± 14.0 months. There were 123 fractured vertebrae, including 79 (64.2%) with endplate fractures and 44 (35.8%) without. Both the adjacent and control discs decreased in signal and height over time (p < 0.001), and the disc adjacent to vertebral fractures had greater signal and height loss than the control disc (p < 0.05). In the presence of endplate fractures, the adjacent discs had greater signal decrease in follow-up (p < 0.05), as compared to those without endplate fractures. Sagittal Cobb angle significantly increased in segments with endplate fractures (p < 0.05). Vertebra fractures were associated with new occurrence of MCs in the fractured vertebra (p < 0.001) but not HIZs in the adjacent disc. Conclusions: Traumatic vertebral fractures were associated with accelerated adjacent disc degeneration, which appears to be further promoted by concomitant endplate fractures. Endplate fractures were associated with progression of segmental kyphosis. [ABSTRACT FROM AUTHOR]

Study Design: An experimental study.Objective: The aim of this study was to determine the effect of polymethylmethacrylate (PMMA) augmentation on the adjacent disc.Summary Of Background Data: Vertebral augmentation with PMMA reportedly may predispose the adjacent vertebra to fracture. The influence of PMMA augmentation on the adjacent disc, however, remains unclear.Methods: Using a retroperitoneal approach, PMMA augmentation was performed for 23 rabbits. For each animal, at least one vertebra was augmented with 0.2 to 0.3 mL PMMA. The disc adjacent to the augmented vertebra and a proximal control disc were studied using magnetic resonance (MR) imaging, histological and molecular level evaluation at 1, 3, and 6 months postoperatively. Marrow contact channels in the endplate were quantified in histological slices and number of invalid channels (those without erythrocytes inside) was rated. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) was performed to determine disc cell apoptosis.Results: On MR images, the signal and height of the adjacent disc did not change 6 months after vertebral augmentation. Histological scores of the adjacent disc increased over time, particularly for the nucleus pulposus. The adjacent disc had greater nucleus degeneration score than the control disc at 3 months (5.7 vs. 4.5, P < 0.01) and 6 months (6.9 vs. 4.4, P < 0.001). There were more invalid marrow contact channels in the endplate of augmented vertebra than the control (43.3% vs. 11.1%, P < 0.01). mRNA of ADAMTS-5, MMP-13, HIF-1α, and caspase-3 were significantly upregulated in the adjacent disc at 3 and 6 months (P < 0.05 for all). In addition, there were more TUNEL-positive cells in the adjacent disc than in the control disc (43.4% vs. 24.0%, P < 0.05) at 6 months postoperatively.Conclusion: Vertebral augmentation can induce early degenerative signs in the adjacent disc, which may be due to impaired nutrient supply to the disc.Level Of Evidence: N/A. [ABSTRACT FROM AUTHOR]

Study Design: A radiological study of type II Modic changes (MCs).Objectives: The aim of this study was to determine the characteristics of type II MCs on fat suppression (FS) magnetic resonance (MR) images and its association with radiological disc degeneration.Summary Of Background Data: Type II MCs are common endplate signal changes on MR images. On the basis of limited histological samples, type II MCs are thought to be stable fat degeneration. FS technique on MR, which can quantify fat content, may be an alternative to explore the pathology of MCs. To date, however, the characteristics of type II MCs on FS sequence have not been studied.Methods: Lumbar MR images conducted in a single hospital during a defined period were reviewed to include those with type II MCs and FS images. On FS images, signal status of type II MCs was visually classified as suppressed or not-suppressed. Signal intensity of vertebral regions with and without MCs was measured quantitatively on T2-weighted (T2W) and FS images to calculate fat content index and validate the visual classification. Using image analysis program Osirix, MCs size and adjacent disc degeneration were measured quantitatively. Paired t-tests and logistic regressions were used to determine the associations studied.Results: Sixty-four lumbar MRIs were included and 150 endplates with type II MCs were studied. Although signal of 37 (24.7%) type II MCs was suppressed on FS images, that of 113 (75.3%) was not suppressed. The discs adjacent to type II MCs had lower signal intensity (0.13 ± 0.003 vs. 0.14 ± 0.004, P < 0.001), lesser disc height (9.73 ± 1.97 vs. 11.07 ± 1.99, P < 0.001) and greater bulging area (80.0 ± 31.4 vs. 61.3 ± 27.5 for anterior bulging, 33.72 ± 21.24 vs. 27.93 ± 12.79 for posterior bulging, and 113.7 ± 39.9 vs. 89.2 ± 35.2 for total bulging, P < 0.05) than normal controls. Type II MCs that were not suppressed on FS image were associated with greater age [odds ratio (OR) = 1.11, P < 0.001], lower height (OR = 0.94, P < 0.05), and greater posterior bulging (OR = 1.05, P < 0.001) at the adjacent disc.Conclusion: Signal of most type II MCs was not suppressed on FS MR images, suggesting that there are ongoing complicated pathologies. Type II MCs may not merely represent fat replacement.Level Of Evidence: 3. [ABSTRACT FROM AUTHOR]