• Journal of radiological science and technology
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• v.44 no.6
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• pp.623-627
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• 2021

Cervical foraminal stenosis is a disease in which the nerves that pass from the spinal canal to the limbs are narrowed and the nerves are compressed or damaged. Due to the lack of an imaging method that provides quantitatively stenosis, this study attempted to evaluate the area of the cervical vertebrae by reconstructing a three-dimensional computed tomography image, and to determine the area of the neural foramen in normal adults to calculate the stenosis rate. Using a three-dimensional image processing program, the surrounding bones including the posterior spinous process, lateral process, and lamellar bones of the cervical vertebra were removed so that the neural foramen could be observed well. A region of interest including the neural foraminal area of the three-dimensional image was set using ImageJ, and the number of pixels in the neural foraminal area was measured. The neural foraminal area was calculated by multiplying the number of measured pixels by the pixel size. To measure the largest neural foraminal area, it was measured between 40~50 degrees in the opposite direction and 15~20 degrees toward the head. The average area of the right C2-3 foramen was 44.32 mm², C3-4 area was 34.69 mm², C4-5 area was 36.41 mm², C5-6 area was 35.22 mm², C6-7 area was 36.03 mm². The average area of the left C2-3 foramen was 42.71 mm², C3-4 area was 32.23 mm², C5-6 area was 34.56 mm², and C6-7 area was 31.89 mm². By creating a reference table based on the neural foramen area of normal adults, the stenosis rate of patients with neural foraminal stenosis could be quantitatively calculated. It is expected that this method can be used as basic data for the diagnosis of cervical vertebral foraminal stenosis.

• Korean Journal of Radiology
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• v.24 no.3
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• pp.224-234
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• 2023

Magnetic resonance imaging (MRI) is a standard imaging modality for diagnosing spinal stenosis, which is a common degenerative disorder in the elderly population. Standardized interpretation of spinal MRI for diagnosing and grading the severity of spinal stenosis is necessary to ensure correct communication with clinicians and to conduct clinical research. In this review, we revisit the Lee grading system for central canal and neural foraminal stenosis of the cervical and lumbar spine, which are based on the pathophysiology and radiologic findings of spinal stenosis.

• Journal of the Korean Society of Radiology
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• v.14 no.7
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• pp.975-980
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• 2020

Cervical neural foraminal stenosis is a very common spinal disease that affects a relatively large number of people of all ages. However, since imaging methods that quantitatively provide neural foraminal stenosis are lacking, this study attempts to present quantitative measurement results by reconstructing 3D computed tomography images. Using a 3D reconstruction software, the surrounding bones were removed, including the spinous process, transverse process, and lamina of the cervical spine so that the neural foramen were well observed. Using Image J, a region of interest including the neural foramen area of the 3D image was set, and the number of pixels of the neural foramen area was measured. The neural foramen area was calculated by multiplying the number of measured pixels by the pixel size. In order to measure the widest area of the neural foramen, it was measured between 40-50 degrees in the opposite direction and 15-20 degrees toward the head. The measured cervical neural foramen area showed consistent measurement values. The largest measured area of the right neural foramen C5-6 was 12.21 ㎟, and after 2 years, the area was measured to be 9.95 ㎟, indicating that 18% stenosis had progressed. Since 3D reconstruction using axial CT scan images, no additional radiation exposure is required, and the area of stenosis can be objectively presented. In addition, it is good to explain to patients with neural stenosis while viewing 3D images, and it is considered a good method to be used in the evaluation of the progression of stenosis and post-operative evaluation.

• Journal of Korean Neurosurgical Society
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• v.41 no.6
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• pp.377-381
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• 2007

Objective : The aim of this study was to evaluate the morphometric changes in neuroforamen in grade I isthmic spondylolisthesis by anterior lumbar interbody fusion [ALIF]. Methods : Fourteen patients with grade I isthmic spondylolisthesis who underwent single level ALIF with percutaneous pedicle screw fixation were enrolled. All patients underwent standing lateral radiography and magnetic resonance imaging [MRI] before surgery and at 1 week after surgery. For quantitative analysis, the foraminal height, width, epidural foraminal height, epidural foraminal width, and epidural foraminal area were evaluated at the mid-portion of 28 foramens using T2-weighted sagittal MRI. For qualitative analysis, degree of neural compression in mid-portion of 28 foramens was classified into 4 grades using T2-weighted sagittal MRI. Clinical outcomes were assessed using Visual Analogue Sale [VAS] scores for leg pain and Oswestry disability index before surgery and at 1 year after surgery. Results : The affected levels were L4-5 in 10 cases and L5-S1 in 4. The mean foraminal height was increased [p<0.001], and the mean foraminal width was decreased [p=0.014] significantly after surgery. The mean epidural foraminal height [p<0.001], epidural foraminal width [p<0.001], and epidural foraminal area [p<0.001] showed a significant increase after surgery. The mean grade for neural compression was decreased significantly after surgery [p<0.001]. VAS scores for leg pain [p=0.001] and Oswestry disability index [p=0.001] was decreased significantly at one year after surgery. Conclusion : Foraminal stenosis in grade I isthmic spondylolisthesis may effectively decompressed by ALIF with percutaneous pedicle screw fixation.

• Journal of the Korean Society of Radiology
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• v.16 no.7
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• pp.919-925
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• 2022

This study is an image reconstruction method after cervical CT scan. According to the oblique coronal reconstruction angle, i would like to suggest the reconstruction angle that can best express neural foraminal bony stricture. The angle created by drawing a line passing through the center of the spinal cord in the midsagittal plane of the cervical spine and the uncovertebral joint was measured. A line passing through the center of the spinal cord was drawn from the neural foramen, and the angle formed with the midsagittal plane was measured and compared. At the C4-5 level, the average was 9.2°, at the C5-6 level, the average was 9.9°, and at the C6-7 level, the average was 8.4°, the neural foraminal angle was measured to be larger than the uncovertebral joint angle. There was a statistically significant difference in mean (p<0.01). Also, it was found that the angle increased toward the lower cervical vertebrae. The angle between the neural foramen of the lower cervical vertebrae (C5-6, C6-7) and the center of the spinal cord is between 55 and 60°. Here, if the oblique coronal image is reconstructed to be 90°, the degree of neural foramen stenosis can be observed well. Because it is an image reconstruction using a conventional CT scan image, it does not receive additional radiation exposure. It is of great significance in diagnosing cervical neural foramen bony stenosis.

• Journal of Korean Neurosurgical Society
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• v.65 no.1
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• pp.74-83
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• 2022

Objective : Oblique lumbar interbody fusion (OLIF) is a surgical technique that utilizes a large interbody cage to indirectly decompress neural elements. The position of the cage relative to the vertebral body could affect the degree of foraminal decompression. Previous studies determined the position of the cage using plain radiographs, with conflicting results regarding the influence of the position of the cage to the degree of neural foramen decompression. Because of the cage obliquity, computed tomography (CT) has better accuracy than plain radiograph for the measurement of the obliquely inserted cage. The objective of this study is to find the correlation between the position of the OLIF cage with the degree of indirect decompression of foraminal stenosis using CT and magnetic resonance imaging (MRI). Methods : We review imaging of 46 patients who underwent OLIF from L2-L5 for 68 levels. Segmental lordosis (SL) was measured in a plain radiograph. The positions of the cage were measured in CT. Spinal canal cross-sectional area (SCSA), and foraminal crosssectional area (FSCA) measurements using MRI were taken into consideration. Results : Patients' mean age was 69.7 years. SL increases 3.0±5.1 degrees. Significant increases in SCSA (33.3%), FCSA (43.7% on the left and 45.0% on the right foramen) were found (p<0.001). Multiple linear regression analysis shows putting the cage in the more posterior position correlated with more increase of FSCA and decreases SL correction. The position of the cage does not affect the degree of the central spinal canal decompression. Obliquity of the cage does not result in different degrees of foraminal decompression between right and left side neural foramen. Conclusion : Cage position near the posterior part of the vertebral body increases the decompression effect of the neural foramen while putting the cage in the more anterior position correlated with increases SL.

• Journal of Korean Neurosurgical Society
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• v.63 no.6
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• pp.747-756
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• 2020

Objective : To evaluate the effectiveness and long-term outcome predictors of percutaneous sacroplasty (PSP). Methods : This single-center study assessed 40 patients with sacral insufficiency fractures using the short-axis technique under C-arm flat-panel detector computed tomography (CT). Two radiologists reviewed the patients' magnetic resonance and CT images to obtain imaging findings before PSP and determine technical success, respectively. The short-term outcomes were visual analog scale score changes and opioid usage reductions. Long-term outcomes were determined using telephone interviews and the North American Spine Society (NASS) patient-satisfaction index at least one year after PSP. Results : Technical success was achieved without any significant complications in 39 patients (97.5%). Telephone interviews were possible with 12 patients and failed in 10 patients; death was confirmed in 18 patients. Fifteen patients (50%) re-visited the hospital and received conservative treatment, including spinal injections. Nine patients reported positive satisfaction (NASS patient-satisfaction index 1 or 2), while the negative satisfaction group (NASS patient-satisfaction index 3 or 4, n=3) showed a higher incidence of compression fractures at the thoracolumbar spine level (66.7% vs. 22.2%) and previous spinal injection history (66.7% vs. 33.3%). The poor response group also showed higher incidences of facet joint arthrosis (100% vs. 55.6%), central canal stenosis (100% vs. 22.2%), neural foraminal stenosis (33.3% vs. 22.2%), scoliosis (100% vs. 33.3%), and sagittal malalignment (100% vs. 44.4%). Conclusion : PSP was effective for sacral insufficiency fractures and showed good long-term outcomes. Combined compression fractures in the thoracolumbar spine and degenerative lumbar pathologies could be possible poor outcome predictors.

• Journal of the Korean Society of Radiology
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• v.82 no.4
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• pp.862-875
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• 2021

Purpose To investigate the MRI features associated with neural foraminal stenosis (NFS) in patients older than 60 years with lumbar (L) radiculopathy. Materials and Methods This study included 133 retrospectively selected patients older than 60 years with lumbar radiculopathy who had undergone a lumbar spine MRI (from January 2018 to April 2018). For L4/L5 and L5/sacral (S)1 levels, NFS was reviewed blindly by two radiologists. Spondylolisthesis, retrolisthesis, disc height loss, disc bulging/herniation/central canal stenosis, ligamentum flavum thickening, and facet hypertrophy were evaluated separately for the NFS and non-NFS groups, and they were compared using univariate and multivariate analyses. Results The univariate analysis revealed that disc height loss (p = 0.006) was associated with NFS for L4/L5. For L5/S1, both spondylolisthesis (p = 0.005) and facet hypertrophy (p = 0.006) were associated with NFS. The multivariate logistic analysis revealed that disc height loss was associated with NFS for L4/L5 [odds ratio (OR) = 4.272; 95% confidence interval (CI) 1.736-10.514]. For L5/S1, spondylolisthesis (OR = 3.696; 95% CI 1.297-10.530) and facet hypertrophy (OR = 6.468; 95% CI 1.283-32.617) were associated with NFS. Conclusion Disc height loss was associated with NFS for L4/L5 and spondylolisthesis and facet hypertrophy were associated with NFS for L5/S1.