Detection and Characterization of Endplate Structural Defects on CT: A Diagnostic Accuracy Study.

STUDY DESIGN: Diagnostic test study. OBJECTIVE: To determine the reliability and validity or diagnostic accuracy of two previously described endplate structural defect (EPSD) assessment methods. SUMMARY OF BACKGROUND DATA: Studies of EPSD may further the understanding of pathoanatomical mechanisms underlying back pain. However, clinical imaging methods used to document EPSD have not been validated, leaving uncertainty about what the observations represent. METHODS: Using an evaluation manual, 418 endplates on CT sagittal slices obtained from 19 embalmed cadavers (9 men and 10 women, aged 62-91 y) were independently assessed by two experienced radiologists and a novice for EPSD using the two methods. The corresponding micro-CT (µCT) from the harvested T7-S1 spines were assessed by another independent rater with excellent intra-rater reliability (Kappa=0.96). RESULTS: Inter-rater reliability was good for presence (Kappa=0.60-0.69) and fair for specific phenotypes (Kappa=0.43-0.58) of EPSD. Erosion, for which the Brayda-Bruno classification lacked a category, was mainly (82.8%) classified as wavy/irregular, while many notched defects (n=15, 46.9%) and Schmorl's nodes (n=45, 79%) were recorded as focal defects using Feng's classification. When compared to µCT, endplate fractures (n=53) and corner defects (n=28) were routinely missed on CT. Endplates classified as wavy/irregular on CT corresponded to erosion (n=29, 21.2%), jagged defects (n=21, 15.3%), calcification (n=19, 13.9%), and other phenotypes on µCT. Some focal defects on CT represented endplate fractures (n=21, 27.6%) on µCT. Overall, with respect to the presence of an EPSD, there was a sensitivity of 70.9% and specificity of 79.1% using Feng's method, and 79.5% and 57.5% using Brayda-Bruno's. Poor to fair inter-rater reliability (k=0.26-0.47) was observed for defect dimensions. CONCLUSION: There was good inter-rater reliability and evidence of criterion validity supporting assessments of EPSD presence using both methods. However, neither method contained all needed EPSD phenotypes for optimal sensitivity, and specific phenotypes were often misclassified.

Thoracolumbar Vertebral Endplate Defect Morphology: A Descriptive Study of Human Cadaveric Spines Using Micro-Computed Tomography.

STUDY DESIGN: A descriptive, cross-sectional cadaver study. OBJECTIVE: This study aimed to provide a thorough depiction of vertebral endplate defects classified based on their morphologic features and reported with respect to size, location, and prevalence in the human cadaveric spines of older adults. SUMMARY OF BACKGROUND DATA: Back pain has been associated with vertebral endplate defects; however, findings have been inconsistent. This is partially due to miscommunication surrounding the classification of endplate defects observed using clinical imaging, and limited knowledge of the types of defects present on the endplate and their prevalence. A comprehensive study of vertebral endplates is needed to clarify types of structural defects, their character, and prevalence. MATERIALS AND METHODS: Using micro-computed tomography, 3-dimensional reconstructed images were created of 409 endplates from 19 cadaveric spines (9 men and 10 women; aged 62-91; T6-S1). Endplate defects were categorized based on their morphology, size, and location to investigate distribution patterns. RESULTS: Seven types of endplate defects were identified: Schmorl nodes, corner fracture or limbus vertebra, other fractures, erosion, jagged surface, calcification, and depressions. Defects were identified on 63.6% of endplates. Multiple defects were present on 19.1% of endplates. Fracture and erosion were the most common defect types. Defects were more common on the endplate cranial to the intervertebral disc and in male specimens ( P = 0.01). Defects were larger in the lumbar spine and the "total area of endplate defect" was larger on the cranial than the caudal endplate in the thoracic spine ( P < 0.05). CONCLUSION: This is the first study of which we are aware that provides a thorough depiction of the morphology and distribution of endplate defects across the entire lower thoracic and lumbar spine (T6-S1) using micro-computed tomography. Results support the presence of several distinct endplate defect phenotypes with different prevalence rates and provide a reference when considering endplate defects in the elderly.

Two-stage collaborative group testing does not improve retention of anatomy among students studying medical radiation technology.

INTRODUCTION: Two-stage collaborative group testing is an assessment format where students first complete a summative assessment independently, and then immediately convene in a small group to complete the same assessment again. Research on two-stage collaborative group testing has shown that it increases immediate learning, improves communication and teamwork, and can lead to enhanced retention of course material; the latter of which is especially important for basic anatomical concepts among health care professionals such as medical radiation technologists. However, such previous research has often employed quasi-experimental designs that may limit both internal and external validity. METHODS: Using a randomized crossover design with both quantitative and qualitative data analyses including robust intra-individual statistical comparisons, this research compared the educational impact of the two-stage collaborative group testing format (the COL condition) to traditional independent testing (the IND condition). Students (n=196) from two successive renditions of an introductory anatomy course were randomly assigned into groups of 3-5 students. Groups worked together throughout the term on various course elements, including three in-class, non-cumulative term tests (TTs). After practicing the collaborative format during TT1, during TT2 half the groups were assigned to the COL condition while the other half were assigned to the IND condition. Groups crossed over for TT3. All students completed a cumulative final examination independently, with performance data from that examination coded and extracted according to previous TT condition. Educational impact was evaluated as both immediate learning (by comparing IND and COL performance on the associated TT) as well as retention (by comparing final examination performance for topics previously IND tested versus previously COL tested). Students' qualitative reflections were coded into categories and juxtaposed against quantitative Likert-style feedback to comprehensively explore students' perception of the testing format for evidence of enjoyment, acceptability, and influence on relevant CAMRT professional competencies. RESULTS: 167 students (85%) consented to data inclusion, with a final course grade of 75.5 ± 10.0%. On average, TT performance was 13.6 ± 11.6% greater on the COL test (90.4 ± 7.6%) than the IND test (76.7 ± 14.3%) (p<0.01, r = 0.76), results that support immediate learning. Contrary to expectations, final examination performance specific to the two experimental conditions was similar, with students earning an average of 69.6 ± 18.3% on questions that pertained to material they were previously IND tested on, and 67.4 ± 19.1% on questions they were previously COL tested on (ns). Students' overall perceptions of the two-stage collaborative group testing format were overwhelmingly positive, with 84% indicating a belief that the format was a constructive learning opportunity and 74% recommending continued use. Written reflections revealed that students believed that collaborative testing enhanced their learning by both clarifying previous mistakes and reinforcing correct knowledge. Relevant CAMRT professional competencies included oral communication and interprofessional skills, capacity for productive teamwork, and collaborative practice. SIGNIFICANCE: Although the results of this study do not support the use of two-stage collaborative group testing for retention of course material, they simultaneously reveal how the testing structure may be uniquely beneficial to students studying within the field of medical radiation sciences while also presenting a pragmatic example of how to implement this unique testing format.