Optimization of the Grashey View Radiograph for Critical Shoulder Angle Measurement: A Reliability Assessment With Zero Echo Time MRI

Abstract

Background: Suboptimal positioning on Grashey view radiographs may limit the prognosticating potential of the critical shoulder angle (CSA) for shoulder disorders. Purpose: To investigate whether radiography optimized according to the latest research is reliable for measuring CSA in comparison with magnetic resonance imaging (MRI) featuring 3-dimensional (3D) zero echo time (ZTE) sequencing, which accentuates the contrast between cortical bone and surrounding soft tissue with high fidelity. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: Patients with shoulder pain were prospectively and consecutively enrolled. All patients had Grashey view radiographs as well as 3.0-T MRI scans with isotropic 3D ZTE sequencing. Acceptable positioning on the radiographs was determined using the ratio of the transverse to longitudinal (RTL) diameter of the lateral glenoid outline; radiographs with an RTL ≥0.25 were repeated. Two observers independently measured the CSA on the radiographs and the coronal oblique reformatted ZTE images, the latter including verification of measurement points by cross-referencing against images from other planes. Reliability of measurements between observers and modalities was analyzed with the intraclass correlation coefficient (ICC). The paired-samples t test was used to compare the differences between imaging modalities. Results: Enrolled were 65 patients (35 female and 30 male; mean age, 40.2 years; range, 25-49 years). Radiographs with optimal positioning (RTL < 0.25) were attained after a mean of 1.6 exposures (range, 1-4); the mean RTL was 0.09 (range, 0-0.20). Interobserver agreement of CSA was excellent for radiographs (ICC = 0.91; 95% CI, 0.84-0.94) and good for ZTE MRI scans (ICC = 0.85; 95% CI, 0.71-0.92). Intermodality agreement of CSA between radiographs and ZTE MRI scans was moderate (ICC = 0.66; 95% CI, 0.48-0.73). The CSA was significantly different between an optimal radiograph (30.7° ± 4.3°) and ZTE MRI scan (31.8° ± 3.8) ( P = .005). Subgroup analysis revealed no significant differences in CSA measurement between ZTE MRI scans and Grashey view radiographs with an RTL of <0.1 ( P = .08). Conclusion: CSA measurement on ZTE MRI scans with anatomic point cross-referencing was significantly different from that on Grashey view radiographs, even with optimal positioning, and radiography may necessitate more than 1 exposure. An RTL of <0.1 ensured reliability of radiographs when other standards of sufficient x-ray exposure were met.

Complete Restoration of Native Glenoid Width Improves Glenohumeral Biomechanics After Simulated Latarjet

“…32 Previous studies also did not quantify the amount of glenoid restoration obtained with Latarjet and instead described the amount of glenoid bone loss before performing a Latarjet without reporting coracoid dimensions. 4,33 The changes in humeral head translation observed in the present study are consistent with those of previous studies that demonstrated that anterior humeral head translation increased as glenoid bone loss increased. 4,33 Consistent with these previous studies, we also showed that anterior humeral translation decreased with abduction and external rotation compared with abduction and neutral rotation.…”

“…4,33 The changes in humeral head translation observed in the present study are consistent with those of previous studies that demonstrated that anterior humeral head translation increased as glenoid bone loss increased. 4,33 Consistent with these previous studies, we also showed that anterior humeral translation decreased with abduction and external rotation compared with abduction and neutral rotation. Future studies should be performed to examine any differences between Latarjet and distal tibial allograft augmentation without the sling effect.…”

“…With the advent of bone-specific MRI sequences, similar methods may also be applied with MRI scans. 33 Normal glenoid width can vary significantly between patients. The findings of this study, in combination with those of Lamplot et al, allow for more precise presurgical planning by accurately measuring the potential coracoid graft size as well as the native glenoid width rather than relying on gestalt or dogma.…”

Bone Tissue in Magnetic Resonance Imaging: Contribution of New Zero Echo Time Sequences

“…Measurement from frontal radiographs was applied in coronal CT reconstructions. Yıldız et al 9 compared CSA measurement between two observers on coronal reconstructions based on 3D ZTE acquisition; interobserver agreement was excellent on radiographs and good on ZTE, but intermodality agreement was only moderate, with a significant difference between the two approaches.…”

Enhanced bone assessment of the shoulder using zero-echo time MRI with deep-learning image reconstruction

“…Recent introduction of commercially available software has facilitated routine implementation of this technique into standard-of-care MR protocols [5][6][7][8]. Benefits of ZTE application in shoulder MRI were previously demonstrated, with strong inter-modality agreements between CT and ZTE images [9][10][11]. As an inherently 3D volume technique, ZTE also accommodates multiplanar reformations and maximum intensity projection renderings, like CT.…”