An assessment of morphological and pathological changes in paravertebral muscle degeneration using imaging and histological analysis: a cross-sectional study

Background The high signal of paravertebral muscle (PVM) on T2-weighted image (T2WI) is usually considered to be fatty degeneration. However, it is difficult to distinguish inflammatory edema from fatty degeneration on T2WI. The purpose of this study was to identify different types of PVM high signal in patients with low back pain (LBP) through magnetic resonance imaging (MRI) and histology. Methods Seventy patients with LBP underwent MRI. The signal change of multifidus both on T2WI and fat suppression image (FSI) was quantified by Image J. Furthermore, 25 of the 70 patients underwent surgery for degenerative lumbar disease and their multifidus were obtained during the operation. Histological analysis of the samples was performed by HE staining. Result Three types of PVM signal changes were identified from the MRI. Type 1 (n = 36) indicated fatty degeneration characterized by a high signal on T2WI and low signal on FSI. High signal on both T2WI and FSI, signifying type 2 meant inflammatory edema (n = 9). Type 3 (n = 25) showed high signal on T2WI and partial signal suppression on FSI, which meant a combination of fatty degeneration and inflammatory edema. Histological results were consistent with MRI. Among the 25 patients who underwent surgery, type 1 (n = 14) showed adipocytes infiltration, type 2 (n = 3) showed inflammatory cells infiltration and type 3 (n = 8) showed adipocytes and inflammatory cells infiltration. Conclusion From our results, there are three types of pathological changes in patients with PVM degeneration, which may help to decide on targeted treatments for LBP.

Alleviating Paravertebral Muscle Spasm after Radiofrequency Ablation Treatment of Hypersensitive Basivertebral and Sinuvertebral Nerves for Chronic Discogenic Back Pain

BACKGROUND: Paraspinal muscle spasm caused by pain from a lumbar degenerative disc is frequently investigated in patients with low back pain. Radiofrequency ablation (RFA) surgery could alleviate paraspinal muscle spasms. OBJECTIVES: We performed RFA surgery on the high-intensity zone (HIZ) and hypersensitive sinuvertebral and basivertebral nerves to evaluate its outcome. The paravertebral muscle cross-sectional area (CSA) was measured on magnetic resonance imaging (MRI) before and after surgery to evaluate the effect of RFA surgery on the paravertebral muscle. STUDY DESIGN: Prospective cohort study. SETTING: A single spine surgery center. METHODS: A comparative study was performed on 2 different uniportal spinal endoscopic surgery groups; 23 patients who underwent RFA surgery for chronic discogenic back pain and 45 patients who underwent posterior decompression surgery for lumbar spinal stenosis with 12 months of follow-up. Paravertebral muscle cross-sectional area, Schiza grade, Modic type, and HIZ size were measured on pre- and post-operative MRI. An endoscopic video review was performed to evaluate the presence of intraoperative twitching and grade the degree of epidural neovascularization and adhesion. Visual analog scale VAS, modified Oswestry Disability Index, ODI and MacNab’s criteria were evaluated for outcome measures. RESULTS: Intraoperative endoscopic video evaluation showed neovascularization and adhesion adjacent to the disc and pedicle. In the RFA surgery group, there were 7 patients (30.43%) with grade 2 and 16 (69.57%) with grade 3 neovascularization; intraoperative twitching was observed in 19 out of 23 patients (82.61%). After performing an RFA on the sinuvertebral and basivertebral nerves for the treatment of discogenic back pain, the results showed significant improvement in pain and disability scores. The mean CSA of the paraspinal muscle in the RFA surgery group was significantly increased after surgery at the L4–L5 and L5–S1 levels (L4–L5: 3901 ± 1096.7 mm² to 4167 ± 1052.1 mm², P = 0.000; L5-S1: 3059 ± 968.5 mm² to 3323 ± 1046.2 mm², P = 0.000) compared to preoperative CSA. LIMITATIONS: This study was limited by its small sample size. CONCLUSION: Hypersensitive sinuvertebral and basivertebral nerves are strongly associated with epidural neovascularization with adhesion and the pathological pain pathway in degenerative disc disease. Epidural neovascularization with adhesion reflects aberrant neurological connections, which are associated with reflex inhibitory mechanisms of the multifidus muscle, which induces spasm. RFA treatment of the region of epidural neovascularization with adhesion effectively treated chronic discogenic back pain and could induce paraspinal muscle spasm release. KEY WORDS: Discogenic back pain, high-intensity zone, sinuvertebral nerve, basivertebral nerve, radiofrequency ablation, multifidus muscle

Influence of Adaptive Statistical Iterative Reconstructions on CT Radiomic Features in Oncologic Patients

Iterative reconstructions (IR) might alter radiomic features extraction. We aim to evaluate the influence of Adaptive Statistical Iterative Reconstruction-V (ASIR-V) on CT radiomic features. Patients who underwent unenhanced abdominal CT (Revolution Evo, GE Healthcare, USA) were retrospectively enrolled. Raw data of filtered-back projection (FBP) were reconstructed with 10 levels of ASIR-V (10–100%). CT texture analysis (CTTA) of liver, kidney, spleen and paravertebral muscle for all datasets was performed. Six radiomic features (mean intensity, standard deviation (SD), entropy, mean of positive pixel (MPP), skewness, kurtosis) were extracted and compared between FBP and all ASIR-V levels, with and without altering the spatial scale filter (SSF). CTTA of all organs revealed significant differences between FBP and all ASIR-V reconstructions for mean intensity, SD, entropy and MPP (all p < 0.0001), while no significant differences were observed for skewness and kurtosis between FBP and all ASIR-V reconstructions (all p > 0.05). A per-filter analysis was also performed comparing FBP with all ASIR-V reconstructions for all six SSF separately (SSF0-SSF6). Results showed significant differences between FBP and all ASIR-V reconstruction levels for mean intensity, SD, and MPP (all filters p < 0.0315). Skewness and kurtosis showed no differences for all comparisons performed (all p > 0.05). The application of incremental ASIR-V levels affects CTTA across various filters. Skewness and kurtosis are not affected by IR and may be reliable quantitative parameters for radiomic analysis.

Degeneration of lumbar paravertebral muscles in lumbar degenerative kyphosis with dynamic sagittal imbalance

Background: The aim of this study was to probe the degeneration of lumbar paravertebral muscles in lumbar degenerative kyphosis (LDK) with dynamic sagittal imbalance (DSI).Method: A total of 132 patients with LDK were enrolled in the study. According to the ΔSVA of the full-spine lateral radiographs before and after walking, enrolled patients were divided into two groups: DSI group (31 cases) and control group (42 case). Lumbar magnetic resonance imaging examination was taken for each subject. Fat infiltration area (FIA)and muscle muscularity of multifidus (MF) and erector spinae (ES) were quantitatively measured though Image J software. Independent-sample t test were performed for comparison of quantitative variables between two groups. P value<0.05 was considered statistically significant.Result: DSI group had lower muscle muscularity both in ES and MF than control group. ES muscularity at L2 level was 0.42±0.08 in DSI group and 0.82±0.17 in control group. (p=0.016). ES muscularity at L4 level was 0.36±0.11in DSI group and 0.76± 0.22 in control group. (p＜0.001).MF muscularity at L2 level was 0.17±0.08 in DSI group and 0.36±0.07in control group. (p＜0.001). MF muscularity at L4 level was 0.34±0.18 in DSI group and 0.48±0.14 in control group. (p＜0.001).DSI group had higher FIA both in ES and MF than control group.ES FIA at L2 level was 0.50±0.17 in DSI group and 0.31±0.10 in control group. (p=0.023). ES FIA at L4 level was 0.55±0.27 in DSI group and 0.34±0.07 in control group. (p＜0.001).MF FIA at L2 level was 0.63±0.22 in DSI group and 0.36±0.12 in control group. (p＜0.001). MF FIA at L4 level was 0.76±0.31 in DSI group and 0.40±0.19 in control group. (p＜0.001). Conclusions: LDK patients with DSI suffered lower muscle muscularity and higher FIA both in ES and MF compared to control group. Our study revealed that the weakness of the paravertebral muscles plays an important role in DSI process, targeted paravertebral muscle strengthening training may be a potentially effective treatment for this disease.

Degeneration of lumbar paravertebral muscles in lumbar degenerative kyphosis with dynamic sagittal imbalance: A case-control study.

Background: The aim of this study was to probe the degeneration of lumbar paravertebral muscles in lumbar degenerative kyphosis (LDK) with dynamic sagittal imbalance (DSI).Method: A total of 132 patients with LDK were enrolled in the study. According to the ΔSVA of the full-spine lateral radiographs before and after walking, enrolled patients were divided into two groups: DSI group (31 cases) and control group (42 case). Lumbar magnetic resonance imaging examination was taken for each subject. Fat infiltration area (FIA)and muscle muscularity of multifidus (MF) and erector spinae (ES) were quantitatively measured though Image J software. Independent-sample t test were performed for comparison of quantitative variables between two groups. P value<0.05 was considered statistically significant.Result: DSI group had lower muscle muscularity both in ES and MF than control group. ES muscularity at L2 level was 0.42±0.08 in DSI group and 0.82±0.17 in control group. (p=0.016). ES muscularity at L4 level was 0.36±0.11in DSI group and 0.76± 0.22 in control group. (p＜0.001).MF muscularity at L2 level was 0.17±0.08 in DSI group and 0.36±0.07in control group. (p＜0.001). MF muscularity at L4 level was 0.34±0.18 in DSI group and 0.48±0.14 in control group. (p＜0.001).DSI group had higher FIA both in ES and MF than control group.ES FIA at L2 level was 0.50±0.17 in DSI group and 0.31±0.10 in control group. (p=0.023). ES FIA at L4 level was 0.55±0.27 in DSI group and 0.34±0.07 in control group. (p＜0.001).MF FIA at L2 level was 0.63±0.22 in DSI group and 0.36±0.12 in control group. (p＜0.001). MF FIA at L4 level was 0.76±0.31 in DSI group and 0.40±0.19 in control group. (p＜0.001). Conclusions: LDK patients with DSI suffered lower muscle muscularity and higher FIA both in ES and MF compared to control group. Our study revealed that the weakness of the paravertebral muscles plays an important role in DSI process, targeted paravertebral muscle strengthening training may be a potentially effective treatment for this disease.

Methotrexate-associated lymphoproliferative disorder of the thoracic spine in a patient with rheumatoid arthritis receiving methotrexate: a case report

Methotrexate-associated lymphoproliferative disorder is recognized as a lymphoma that occurs following methotrexate administration. The lesion of the spine is extremely rare, and only one case of lesion in the lumbar spine has been reported so far. Here, we present a case of methotrexate-associated lymphoproliferative disorder of the thoracic spine in a 54-year-old woman with rheumatoid arthritis. The lesion formed an extra-skeletal tumor mass from lateral to the vertebral body to the paravertebral muscle extending posterior to the epidural space without bone destruction. Magnetic resonance imaging showed low signal intensities on both T1- and T2-weighted images and high signal intensity with short-tau inversion recovery. These radiological findings were similar to those for primary spinal lymphoma. The lesion rapidly paralyzed the patient, forcing her to be treated with posterior spinal decompression. The lesion could not be resected because it adhered to the dura. Following the histopathological diagnosis as methotrexate-associated lymphoproliferative disorder, methotrexate administration was terminated. The remaining mass lesion showed complete regression within 6 months. Methotrexate-associated lymphoproliferative disorder, which could be cured by the discontinuation of methotrexate, should be considered a differential diagnosis in spinal lesion cases showing lymphoma-like appearance with methotrexate treatment to avoid unnecessary treatments.