To assess the learnability of two magnetic resonance imaging (MRI) grading systems for lumbar central canal stenosis based on inter-observer agreement and test-retest reliability of doctors with no prior knowledge of the two systems. Two clinical fellows, one novice radiology resident, one neurosurgeon, and one orthopedic surgeon, who were unaware of the two qualitative MRI grading systems prior to this study, acquainted themselves with the teaching files. All five observers independently assessed the LCCS grade of 70 patients using T2-weighted axial magnetic resonance images at the L2-3, L3-4, L3-4, and L5-S1 disc levels. Analysis was performed twice at an interval of two months. The inter-observer agreement among all five readers was excellent and test-retest reliability was moderate to excellent for both the Schizas and Lee systems. Positive percentage agreements were found to be over 0.8 in almost all observers with relatively narrow 95% confidence limits. Both Schizas and Lee MRI grading systems for LCCS are reliable grading systems, and can be used as a learnable method for both clinicians and radiologists.

The purpose of this study was to evaluate the long-term efficacy of ultrasound (US)-guided steroid injections in patients with piriformis syndrome. Between January 2010 and October 2012, 63 patients (23 men and 40 women; average age, 63.2 years; range, 24 to 90 years) were diagnosed with piriformis syndrome based on clinical history, electromyography, and flexion-adduction-internal rotation test results. They were divided into two groups. The first group (37 subjects) received a US-guided steroid injection around the piriformis muscle. The second group (26 subjects) received both piriformis muscle and spinal epidural injections. The therapeutic effect was categorized as improvement, partial improvement, or failure depending on the degree of symptom alleviation one month after injection, based on a review of each patient's medical records. In the first group, 15 patients (40.5%) showed improvement, seven (18.9%) showed partial improvement, and 15 (40.5%) failed to respond to the initial treatment. In the second group, eight patients (30.8%) showed improvement, 11 (42.3%) showed partial improvement, and seven (26.9%) failed to respond to the initial treatment. A second piriformis injection was performed in four cases, after which two patients showed improvement within 3 years, but the other two showed no therapeutic effect. US-guided steroid injection may be an effective treatment option for patients with piriformis syndrome.

Lee YK, et al. J Korean Med Sci. 2016 Nov;31(11):1822-1827. https://doi.org/10.3346/jkms.2016.31.11.1822

Kim DH, et al. Korean J Radiol. 2024 Feb;25:e27. https://doi.org/10.3348/kjr.2023.0671

BACKGROUND AND PURPOSE: Longitudinally extensive transverse myelitis is a well-documented spinal manifestation of neuromyelitis optica spectrum disorders, however, other forms of nontumorous myelopathy can also manifest as longitudinally extensive transverse myelitis. Our aim was to evaluate the MR imaging features of aquaporin-4 antibody–positive longitudinally extensive transverse myelitis, which is strongly associated with neuromyelitis optica spectrum disorders. MATERIALS AND METHODS: We evaluated cervicomedullary junction involvement, cord expansion ratios, bright spotty lesions, the number of involved segments, skipped lesions, enhancement patterns, and axial distribution patterns using spinal MR imaging of 41 patients with longitudinally extensive transverse myelitis who underwent aquaporin-4 antibody testing. Univariate logistic regression analysis was performed to identify factors associated with aquaporin-4 antibody seropositivity, which were then used to develop a scoring system for diagnosing aquaporin-4 antibody–positive longitudinally extensive transverse myelitis. Interrater reliability for cord expansion ratio measurement and bright spotty lesions was determined using intraclass correlation coefficients and κ values, respectively. RESULTS: Fifteen patients with longitudinally extensive transverse myelitis were aquaporin-4 antibody–positive. Sex (female), cervicomedullary junction involvement, a cord expansion ratio of >1.4, and bright spotty lesions were significantly associated with aquaporin-4 antibody seropositivity. The sensitivity and specificity of the scoring system were 73.3% and 96.2%, respectively. The interclass correlation value for the cord expansion ratio was 0.78, and the κ value for bright spotty lesions was 0.61. CONCLUSIONS: Our scoring system, based on cervicomedullary junction involvement, higher cord expansion ratio, bright spotty lesions, and female sex, can facilitate the timely diagnosis of neuromyelitis optica spectrum disorders.