Automated Detection and Segmentation of Bone Metastases on Spine MRI Using U-Net: A Multicenter Study.

OBJECTIVE: To develop and evaluate a deep learning model for automated segmentation and detection of bone metastasis on spinal MRI. MATERIALS AND METHODS: We included whole spine MRI scans of adult patients with bone metastasis: 662 MRI series from 302 patients (63.5 ± 11.5 years; male:female, 151:151) from three study centers obtained between January 2015 and August 2021 for training and internal testing (random split into 536 and 126 series, respectively) and 49 MRI series from 20 patients (65.9 ± 11.5 years; male:female, 11:9) from another center obtained between January 2018 and August 2020 for external testing. Three sagittal MRI sequences, including non-contrast T1-weighted image (T1), contrast-enhanced T1-weighted Dixon fat-only image (FO), and contrast-enhanced fat-suppressed T1-weighted image (CE), were used. Seven models trained using the 2D and 3D U-Nets were developed with different combinations (T1, FO, CE, T1 + FO, T1 + CE, FO + CE, and T1 + FO + CE). The segmentation performance was evaluated using Dice coefficient, pixel-wise recall, and pixel-wise precision. The detection performance was analyzed using per-lesion sensitivity and a free-response receiver operating characteristic curve. The performance of the model was compared with that of five radiologists using the external test set. RESULTS: The 2D U-Net T1 + CE model exhibited superior segmentation performance in the external test compared to the other models, with a Dice coefficient of 0.699 and pixel-wise recall of 0.653. The T1 + CE model achieved per-lesion sensitivities of 0.828 (497/600) and 0.857 (150/175) for metastases in the internal and external tests, respectively. The radiologists demonstrated a mean per-lesion sensitivity of 0.746 and a mean per-lesion positive predictive value of 0.701 in the external test. CONCLUSION: The deep learning models proposed for automated segmentation and detection of bone metastases on spinal MRI demonstrated high diagnostic performance.

[Imaging Evaluation of Early and Long-Term Complications Associated with the Postoperative Spine]. / 척추 ìˆ˜ìˆ í›„ 영상 평가: 초기 및 중장기 합병증.

As the number of spinal surgeries being performed expands, the number of medical imaging procedures such as radiography, CT, and MRI is also increasing, and the importance of their interpretation is becoming more significant. Herein, we present the radiological findings of a variety of complications that can occur after spinal surgery and discuss how effectively and accurately they can be diagnosed through imaging. In particular, this study details the characteristic imaging findings specific to the early and long-term postoperative periods. Early complications of spinal surgery include improper placement of surgical instruments (instrument malpositioning), seromas, hematomas, pseudomeningoceles, and infections in the region surrounding the surgical site. Conversely, long-term complications may include osteolysis around surgical instruments, failure of fusion, adjacent segment disease, and the formation of epidural fibrosis or scar tissue. A precise understanding of the imaging assessments related to complications arising after spinal surgery is crucial to ensure timely and accurate diagnosis, which is necessary to achieve effective treatment.

Assessing visibility and bone changes of spinal metastases in CT scans: a comprehensive analysis across diverse cancer types.

OBJECTIVES: To analyze the characteristics of spinal metastasis in CT scans across diverse cancers for effective diagnosis and treatment, using MRI as the gold standard. METHODS: A retrospective study of 309 patients from four centers, who underwent concurrent CT and spinal MRI, revealing spinal metastasis, was conducted. Data on metastasis including total number, volume, visibility on CT (visible, indeterminate, or invisible), and type of bone change were collected. Through chi-square and Mann-Whitney U tests, we characterized the metastasis across diverse cancers and investigated the variation in the intra-individual ratio representing the percentage of lesions within each category for each patient. RESULTS: Out of 3333 spinal metastases from 309 patients, 55% were visible, 21% indeterminate, and 24% invisible. Sclerotic and lytic lesions made up 47% and 43% of the visible and indeterminate categories, respectively. Renal cell carcinoma (RCC), prostate cancer, and hepatocellular carcinoma (HCC) had the highest visibility at 86%, 73%, and 67% (p < 0.0001, p < 0.0001, and p = 0.003), while pancreatic cancer was lowest at 29% (p < 0.0001). RCC and HCC had significantly high lytic metastasis ratios (interquartile range (IQR) 0.96-1.0 and 0.31-1.0, p < 0.001 and p = 0.005). Prostate cancer exhibited a high sclerotic lesion ratio (IQR 0.52-0.97, p < 0.001). About 39% of individuals had invisible or indeterminate lesions, even with a single visible lesion on CT. The intra-individual ratio for indeterminate and invisible metastases surpassed 18%, regardless of the maximal size of the visible metastasis. CONCLUSIONS: This study highlights the variability in characteristics of spinal metastasis based on the primary cancer type through unique lesion-centric analysis.

Cerebrospinal fluid flow artifact reduction with deep learning to optimize the evaluation of spinal canal stenosis on spine MRI.

PURPOSE: The aim of study was to employ the Cycle Generative Adversarial Network (CycleGAN) deep learning model to diminish the cerebrospinal fluid (CSF) flow artifacts in cervical spine MRI. We also evaluate the agreement in quantifying spinal canal stenosis. METHODS: For training model, we collected 9633 axial MR image pairs from 399 subjects. Then, additional 104 image pairs from 19 subjects were gathered for the test set. The deep learning model was developed using CycleGAN to reduce CSF flow artifacts, where T2 TSE images served as input, and T2 FFE images, known for fewer CSF flow artifacts. Post training, CycleGAN-generated images were subjected to both quantitative and qualitative evaluations for CSF artifacts. For assessing the agreement of spinal canal stenosis, four raters utilized an additional 104 pairs of original and CycleGAN-generated images, with inter-rater agreement evaluated using a weighted kappa value. RESULTS: CSF flow artifacts were reduced in the CycleGAN-generated images compared to the T2 TSE and FFE images in both quantitative and qualitative analysis. All raters concordantly displayed satisfactory estimation results when assessing spinal canal stenosis using the CycleGAN-generated images with T2 TSE images (kappa = 0.61-0.75) compared to the original FFE with T2 TSE images (kappa = 0.48-0.71). CONCLUSIONS: CycleGAN demonstrated the capability to produce images with diminished CSF flow artifacts. When paired with T2 TSE images, the CycleGAN-generated images allowed for more consistent assessment of spinal canal stenosis and exhibited agreement levels that were comparable to the combination of T2 TSE and FFE images.

Magnetic Resonance Imaging Grading Systems for Central Canal and Neural Foraminal Stenoses of the Lumbar and Cervical Spines With a Focus on the Lee Grading System.

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.

A rabbit model for embolic infarct potentials of injectables using ultrasound-guided carotid artery puncture.

In order to evaluate the in vivo thrombogenicity of injectable agents, a suitable animal model is needed. We introduce an ultrasound-guided non-selective cerebral artery occlusion model via the common carotid arteries of rabbits. A total of 30 rabbits were assigned to an experimental group (n = 20) and a control group (n = 10). Each group received 2 mL suspension of embolic agent or 2 mL of normal saline, respectively, under ultrasound guidance. The animals were observed for immediate reaction and underwent magnetic resonance imaging (MRI) scan. Follow-up neurologic examination was conducted 24 h following the procedure. In 7 of the 30 rabbits, 2 in the control group and 5 in the experimental group, the administration of either normal saline or the embolic agent failed. Among the successfully injected 15 experimental animals, 14 showed neurologic impairment or deceased, whereas 1 animal did not show significant neurologic deficit. The MRI of 4 experimental animals showed detectable cerebral infarction on diffusion-weighted imaging. None of the 8 control animals showed neurologic abnormality and their brain MRI was normal. Our minimally invasive model is technically feasible and competent to show thrombogenecity of an injectable agent and consequent in vivo neurologic outcome.

Florid Reactive Periostitis of the Clavicle: A Case Report.

Florid reactive periostitis (FRP) is a rare benign fibro-osseous proliferation, occurring mostly in the short tubular bones of hands and rarely in the long tubular bones. We report a surgically confirmed case of FRP involving the clavicle in a 26-year-old male. On MRI scans, a soft tissue mass with T2 high signal intensity was found that originated from the periosteum of the clavicle and included surrounding a periosteal elevation and perilesional soft tissue edema. Strong contrast enhancement was noted inside the mass and along the periosteum involving more than half of the circumference of the clavicle. Serial radiographs revealed a soft tissue mass without mineralization that turned into an ossified mass with a solid periosteal reaction within a month.

Ensemble deep learning model for predicting anterior cruciate ligament tear from lateral knee radiograph.

OBJECTIVE: To develop an ensemble deep learning model (DLM) predicting anterior cruciate ligament (ACL) tears from lateral knee radiographs and to evaluate its diagnostic performance. MATERIALS AND METHODS: In this study, 1433 lateral knee radiographs (661 with ACL tear confirmed on MRI, 772 normal) from two medical centers were split into training (n = 1146) and test sets (n = 287). Three single DLMs respectively classifying radiographs with ACL tears, abnormal lateral femoral notches, and joint effusion were developed. An ensemble DLM predicting ACL tears was developed by combining the three DLMs via stacking method. The sensitivities, specificities, and area under the receiver operating characteristic curves (AUCs) of the DLMs and three radiologists were compared using McNemar test and Delong test. Subgroup analysis was performed to identify the radiologic features associated with the sensitivity. RESULTS: The sensitivity, specificity, and AUC of the ensemble DLM were 86.8% (95% confidence interval [CI], 79.9-92.0%), 89.4% (95% CI, 83.4-93.8%), and 0.927 (95% CI, 0.891-0.954), achieving diagnostic performance comparable with that of a musculoskeletal radiologist (P = 0.193, McNemar test; P = 0.131, Delong test). The AUC of the ensemble DLM was significantly higher than those of non-musculoskeletal radiologists (P = 0.043, P < 0.001). The sensitivity of the DLM was higher than that of the radiologists in the absence of an abnormal lateral femoral notch or joint effusion. CONCLUSION: The diagnostic performance of the ensemble DLM in predicting lateral knee radiographs with ACL tears was comparable to that of a musculoskeletal radiologist.

A problem-based approach in musculoskeletal ultrasonography: central metatarsalgia.

Ultrasonography (US) is a useful diagnostic method that can be easily applied to identify the cause of metatarsalgia. The superficial location of structures in the foot, dynamic capability of US, and the ability to perform direct real-time evaluations of the pain site are also strong advantages of US as a modality for examining the foot. Moreover, knowing the possible pain sources to investigate when a patient has a specific site of pain will enhance the diagnostic quality of US, and will help radiologists to perform US efficiently and effectively. The purpose of this article is to review the common etiologies of metatarsalgia including Morton's neuroma, plantar plate injury, synovitis, tenosynovitis, bursitis, and metatarsal fractures, and to discuss their US features.

Marginal impaction associated with posterior malleolar fracture in rotational ankle injury.

AIM: This study aimed to introduce the circle drawing method for the evaluation of marginal impaction associated with posterior malleolar fractures (PMFs) on computed tomography (CT) images and evaluate the marginal impaction based on PMF patterns (Bartonícek classification) in rotational ankle fractures. METHODS: From January 2014 to December 2019, A total of 299 patients were reviewed retrospectively. The circle drawing method consists of matching the articular surface of the intact tibial plafond with a best-fitted circle on the sagittal CT image. The mismatch gap between the circle and the articular surface indicates the presence of marginal impaction. To validate the circle drawing method, we assessed CT images of 60 ankles without fracture at the medial, central, and lateral parts using the new method. RESULTS: Based on the review of the preoperative CT scan, 153 out of 299 patients (51.2%) were identified as having PMFs. Among them, 57 patients (37.3%) had marginal impaction associated with PMFs. For small posterolateral type 2 fractures, 58% of patients (47/81) had marginal impaction, and its incidence was most frequent among all types (P<.01). For posteromedial extended type 3 fractures, 27% of patients (8/30) had marginal impaction. Extraincisural type 1 and large posterolateral triangular type 4 fractures were rarely associated with marginal impaction. Among the 180 zones of 60 ankles without fracture, 171 zones (95%) were perfectly fitted to a best-fitted circle. CONCLUSIONS: The marginal impaction associated with PMFs is often observed in rotational ankle fractures, particularly in small posterolateral and posteromedial extended fractures.

A problem-based approach in musculoskeletal ultrasonography: heel pain in adults.

Musculoskeletal ultrasonography (US) has unique advantages, such as excellent spatial resolution for superficial structures, the capability for dynamic imaging, and the ability for direct correlation and provocation of symptoms. For these reasons, US is increasingly used to evaluate problems in small joints, such as the foot and ankle. However, it is almost impossible to evaluate every anatomic structure within a limited time. Therefore, US examinations can be faster and more efficient if radiologists know where to look and image patients with typical symptoms. In this review, common etiologies of heel pain are discussed in a problem-based manner. Knowing the common pain sources and being familiar with their US findings will help radiologists to perform accurate and effective US examinations.

Spinal nerve signal intensity on Dixon T2-weighted water-only sequence: an important outcome predictor after lumbar transforaminal epidural injection.

OBJECTIVES: To evaluate the role of Dixon T2-weighted water-fat separation technique in predicting the outcome of lumbar transforaminal epidural injections (TFESIs). METHODS: Patients who underwent TFESI of a single spinal nerve within 3 months after magnetic resonance imaging (MRI) exam between August 2018 and April 2020 were identified. The patients were classified into positive or negative outcome groups based on the response to the TFESI procedure. Two musculoskeletal radiologists measured the signal intensity of the injected side spinal nerves, contralateral side spinal nerves, and subcutaneous fat on axial Dixon T2-weighted water-only images, and the diameter of spinal nerve on axial Dixon T2-weighted in-phase images of the pre-procedural MRI. The measured values of the injected side spinal nerves were compared between the two groups and with the contralateral side spinal nerve. RESULTS: A total of 94 patients were included, 76 in the positive outcome group and 18 in the negative outcome group. The mean signal intensity and the nerve-to-fat signal ratio of the injected side spinal nerve were significantly higher in the positive outcome group than in the negative outcome group (793.78 vs. 679.19, p = 0.016; 4.21 vs. 3.28, p = 0.003). In the positive outcome group, the diameter of the spinal nerve was significantly higher on the injected side than on the contralateral side (6.91 mm vs. 6.37 mm, p = 0.016). CONCLUSIONS: The mean signal intensity and the nerve-to-fat signal ratio of the spinal nerve on axial Dixon T2-weighted water-only images can help predict patient response to the TFESI. KEY POINTS: • Applying the Dixon technique to lumbar spine MRI can help predict patient response to the TFESI procedure. • An increased nerve-to-fat signal ratio and mean spinal nerve signal intensity on axial Dixon T2-weighted water-only images predicted favorable TFESI outcomes.

Readability of extraspinal organs on scout images of lumbar spine MRI according to different protocols.

BACKGROUND: Scout images of lumbar spine MRI often include the extraspinal organs, which are barely included in routine MRI and can be a potential cause of lumbar pain. PURPOSE: To evaluate the readability of scout images for extraspinal organs in lumbar spine MRI according to different protocols. MATERIALS AND METHODS: A total of 150 patients who underwent 1.5 T or 3 T lumbar spine MRI from March to September 2015 at three hospitals with different scout image protocols, were selected. Two radiologists independently reviewed the scout images to investigate whether exclusive diagnosis of major diseases involving the femoral head, femoral neck, sacroiliac joint, and kidneys was possible. Readability levels were divided into four categories: definitely, possibly, limited, and non-evaluable. The readability of scout images according to the protocols was compared using Chi-square test. Interobserver agreement for the readability level of scout images was assessed using weighted κ statistics. RESULTS: Of 150 patients, "definitely evaluable" cases classified by two readers were 50-62 (33.3-41.3%) for femoral head (κ = 0.63-0.71), 37-66 (24.7-44.0%) for femoral neck (κ = 0.41-0.48), 72-93 (48.0-62.0%) for sacroiliac joint (κ = 0.35-0.37), and 63-73 (42.0-48.7%) for kidneys (κ = 0.45-0.47). More than 50% of femoral heads were classified as readable (definitely or possible evaluable) cases by two readers with excellent interobserver agreement. The readability level of scout images was significantly different according to image protocols including the MRI sequence, number of coronal plane slices, and intersection gap of coronal plane slices (p≤0.015). CONCLUSION: Scout images of lumbar spine MRI may be readable enough to rule out some major diseases of extraspinal organs. Standardization of the protocol will be needed to validate the potential role of scout images for screening extraspinal organs.

Efficacy of computed tomography in prediction of operability of L5/S1 foraminal stenosis using region of interest: A STROBE-compliant retrospective study.

Symptoms of intervertebral foraminal stenosis are caused by compression of nerve root exiting the intervertebral foramen. Many attempts to measure the size of the neuromuscular exit have been made; however, only a few studies to compare the area differences between foramens by computed tomography (CT) were done. In this retrospective comparative study, we used the region of interest (ROI) in CT to measure and compare the area of intervertebral foramen between the healthy control group and the patient group.Eighty-one patients who underwent CT of the lumbar spine between May 2014 and December 2017 were enrolled. Using the medical imaging program, the foraminal area between L5 and S1 vertebrae was measured on the sagittal, coronal, and axial planes using ROI. Four groups were established for comparison: those diagnosed with foraminal stenosis by a radiologist and those who were not, those diagnosed with foraminal stenosis by orthopedic surgeons and those who were not. These groups were further divided into subcategories depending on whether the area was operated on for foraminal stenosis. Interobserver and intraobserver agreements were assessed.The mean age of patients was 56.5 years (range 17-84). The foraminal area of the surgical group on sagittal plane was significantly narrower than the control group (P = .005). However, the difference between the 2 groups on axial and coronal planes was not statistically significant (P > .1). Foraminal area <80 mm on sagittal images was a statistically significant risk factor for clinical symptom (P = .028) and that <65 mm was a statistically significant risk factor in predicting operability (P = .01). Interobserver and intraobserver agreements were fair to good on axial and coronal planes (about 0.7), whereas the agreements were excellent on sagittal plane (>0.9).In this study, we proved that measuring the intervertebral foraminal area using the ROI in CT in the lumbar spine is useful for diagnosing L5-S1 foraminal stenosis, especially on sagittal plane. Furthermore, not only does it provide aid in diagnosis, but it also helps predicting the operability of foraminal stenosis.

Subclinical Coronary Atherosclerosis: Implication of Coronary Computed Tomography Angiography Findings among Statin Candidates according to the 2013 ACC/AHA Cholesterol Management Guidelines.

OBJECTIVE: To analyze the cardiovascular outcome of statin medication in individuals retrospectively categorized on the basis of the 2013 American College of Cardiology and American Heart Association (ACC/AHA) guidelines risk assessment and to determine the additional prognostic value of coronary computed tomography angiography (CCTA) in assessing cardiovascular disease (CVD) risk in this group. MATERIALS AND METHODS: This retrospective study reviewed 4255 asymptomatic individuals who had undergone self-referred CCTA with a median follow-up period of 87 months. The primary endpoint was major adverse cardiac events (MACEs); these included cardiac death, nonfatal myocardial infarction, and unstable angina. Individuals recommended for statins according to the ACC/AHA guidelines were analyzed by their assessed risk. RESULTS: MACE occurrence was significantly higher in the statin-recommended (SR) group with significant coronary artery disease (CAD) than in those with insignificant CAD (p < 0.001). In individuals with a normal coronary artery on CCTA, MACEs did not occur regardless of statin medication. In the SR group with significant CAD, there was no significant difference between statin users and non-users (p = 0.810). However, in cases with insignificant CAD, the event-free survival was significantly lower among statin users (p = 0.034). In patients recommended for moderate-intensity statins, the segment involvement score on CCTA was significantly associated with a higher risk of MACEs (hazard ratio 2.558; p = 0.001). CONCLUSION: CCTA might have a potential role in CVD risk stratification among asymptomatic statin candidates.

Evaluation of the responsiveness of outcome measures after spine injection: A retrospective study.

Discrepancies in patients' responses to various outcome measures challenge clinicians' evaluation of treatment outcomes. Therefore, we aimed to 1) evaluate the concordance of outcome measures after spine injection, 2) determine the patient variables that lead to discordant responses, and 3) suggest practical outcome measure for spine injections with good responsiveness. From October 2014 to November 2014, 164 patients with neck or low back pain who visited our outpatient clinics and had spine injections on the previous visit were enrolled. We asked patients to report changes in their symptom in the form of outcome measures: numeric rating scale, Oswestry disability index, neck disability index, residual symptom percentage and global perceived effect. The responses were categorized into three groups according to the degree of change; not improved, minimally improved, and significantly improved. The concordances of these categorized answers were evaluated. When "significantly improved" was considered as true improvement, 46 (28%) of the 164 patients had discordant responses to the four measures. There was no significant patients' variable that affects discordance in the outcome measures. Good agreement was shown between the global perceived effect and residual symptom percentage, while the Oswestry disability index had poor agreement with the other measurements. The calculated numeric rating scale and residual symptom percentage also had low levels of agreement. However, patients with severe pre-treatment pain tended to have better agreement. In conclusion, this result suggest that the residual symptom percentage may be a more practical for clinicians and better represent patients' improvements after spine injection.

Ultrasound-guided cable-free 13-gauge vacuum-assisted biopsy of non-mass breast lesions.

PURPOSE: To compare the outcomes of ultrasound-guided core biopsy for non-mass breast lesions by the novel 13-gauge cable-free vacuum-assisted biopsy (VAB) and by the conventional 14-gauge semi-automated core needle biopsy (CCNB). MATERIALS AND METHODS: Our institutional review board approved this prospective study, and all patients provided written informed consent. Among 1840 ultrasound-guided percutaneous biopsies performed from August 2013 to December 2014, 145 non-mass breast lesions with suspicious microcalcifications on mammography or corresponding magnetic resonance imaging finding were subjected to 13-gauge VAB or 14-gauge CCNB. We evaluated the technical success rates, average specimen numbers, and tissue sampling time. We also compared the results of percutaneous biopsy and final surgical pathologic diagnosis to analyze the rates of diagnostic upgrade or downgrade. RESULTS: Ultrasound-guided VAB successfully targeted and sampled all lesions, whereas CCNB failed to demonstrate calcification in four (10.3%) breast lesions with microcalcification on specimen mammography. The mean sampling time were 238.6 and 170.6 seconds for VAB and CCNB, respectively. No major complications were observed with either method. Ductal carcinoma in situ (DCIS) and atypical ductal hyperplasia (ADH) lesions were more frequently upgraded after CCNB (8/23 and 3/5, respectively) than after VAB (2/26 and 0/4, respectively P = 0.028). CONCLUSION: Non-mass breast lesions were successfully and accurately biopsied using cable-free VAB. The underestimation rate of ultrasound-detected non-mass lesion was significantly lower with VAB than with CCNB. TRIAL REGISTRATION: CRiS KCT0002267.

Is multidetector computed tomography comparable to magnetic resonance imaging for assessment of lumbar foraminal stenosis?

Background Both multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) are used for assessment of lumbar foraminal stenosis (LFS). Therefore, it is relevant to assess agreement between these imaging modalities. Purpose To determine intermodality, inter-, and intra-observer agreement for assessment of LFS on MDCT and MRI. Material and Methods A total of 120 foramina in 20 patients who visited our institution in January and February 2014 were evaluated by six radiologists with different levels of experience. Radiologists evaluated presence and severity of LFS on sagittal CT and MR images according to a previously published LFS grading system. Intermodality agreement was analyzed by using weighted kappa statistics, while inter- and intra-observer agreement were analyzed by using intraclass correlation coefficients (ICCs) and kappa statistics. Results Overall intermodality agreement was moderate to good (kappa, 0.478-0.765). In particular, two professors and one fellow tended to overestimate the degree of LFS on CT compared with MRI. For inter-observer agreement of all six observers, ICCs indicated excellent agreement for both CT (0.774) and MRI (0.771), while Fleiss' kappa values showed moderate agreement for CT (0.482) and MRI (0.575). There was better agreement between professors and fellows compared with residents. For intra-observer agreement, ICCs indicated excellent agreement, while kappa values showed good to excellent agreement for both CT and MRI. Conclusion MDCT was comparable to MRI for diagnosis and assessment of LFS, especially for experienced observers. However, there was a tendency to overestimate the degree of LFS on MDCT compared with MRI.

A New MRI Grading System for Cervical Foraminal Stenosis Based on Axial T2-Weighted Images.

OBJECTIVE: The purpose of this study was to evaluate the reliability of a new magnetic resonance imaging (MRI) grading system for cervical neural foraminal stenosis (NFS). MATERIALS AND METHODS: Cervical NFS at bilateral C4/5, C5/6, and C6/7 was classified into the following three grades based on the T2-weighted axial images: Grade 0 = absence of NFS, with the narrowest width of the neural foramen greater than the width of the extraforaminal nerve root (EFNR); Grade 1 = the narrowest width of the neural foramen the same or less than (but more than 50% of) the width of the EFNR; Grade 2 = the width of the neural foramen the same or less than 50% of the width of the EFNR. The MRIs of 96 patients who were over 60 years old (M:F = 50:46; mean age 68.4 years; range 61-86 years) were independently analyzed by seven radiologists. Interobserver and intraobserver agreements were analyzed using the percentage agreement, kappa statistics, and intraclass correlation coefficient (ICC). RESULTS: For the distinction among the three individual grades at all six neural foramina, the ICC ranged from 0.68 to 0.73, indicating fair to good reproducibility. The percentage agreement ranged from 60.2% to 70.6%, and the kappa values (κ = 0.50-0.58) indicated fair to moderate agreement. The percentages of intraobserver agreement ranged from 85.4% to 93.8% (κ = 0.80-0.92), indicating near perfect agreement. CONCLUSION: The new MRI grading system shows sufficient interobserver and intraobserver agreement to reliably assess cervical NFS.