Coracoclavicular bursal changes on MRI: a diagnostic consideration in patients with shoulder pain and reduced coracoclavicular distance.

OBJECTIVE: To describe MRI changes of the coracoclavicular bursa in patients presenting with shoulder pain and examine whether there is an association with coracoclavicular distance measurements. METHODS: Retrospective analysis of 198 shoulder 3T MRI scans for patients with shoulder pain was performed. Two musculoskeletal trained radiologists read all MRI scans. Inter-reader and intra-reader agreements for the bursal changes were assessed using the Kappa coefficient. The coracoclavicular distance was stratified into three intervals: < 5 mm, 5-10 mm, and > 10 mm. Statistical analysis for the coracoclavicular bursal changes and coracoclavicular distance was conducted using Fisher's exact test. RESULTS: Coracoclavicular bursal changes were detected in 9% (n = 18/198) of patients. There was a statistically significant association between coracoclavicular distance (< 5 mm) and the presence of coracoclavicular bursal changes (p-value = 0.011). All patients (100%, n = 18/18) with coracoclavicular bursal fluid presented with shoulder pain with 44.5% of the patients (n = 8/18) describing anterior shoulder pain. A statistically significant association was detected between coracoclavicular bursal changes and anterior shoulder pain (p-value = 0.0011). Kappa coefficient for the bursal changes inter-reader agreement was moderate (0.67) and the intra-reader agreement was almost perfect (0.91). CONCLUSION: Coracoclavicular bursal changes were detected in 9% of shoulder MRI scans and were associated with reduced coracoclavicular distance (< 5 mm) suggesting an underlying mechanical disorder such as a friction or an impingement process. Documenting coracoclavicular bursal changes in the MRI report could help address patients' concerns and guide further management particularly in the context of shoulder pain and coracoclavicular distance of less than 5 mm.

Development of a risk assessment model to differentiate malignant and benign musculoskeletal soft-tissue masses on magnetic resonance imaging.

INTRODUCTION: This study aimed to develop a risk stratification model to differentiate benign and malignant MRI-imaged musculoskeletal soft-tissue tumours, informing decisions surrounding biopsy and follow-up imaging. METHODS: Imaging of patients who underwent MRI and subsequent biopsy to evaluate a soft-tissue mass was retrospectively reviewed. Features analysed included patient age; tumour size; shape; margins; enhancement pattern; signal intensity pattern; deep fascia, neurovascular bundle, bone and joint involvement; and the presence of necrosis, haemorrhage, oedema and intralesional fat. Univariate comparisons, by final histopathological status, employed t-tests and chi-square tests, followed by simple and multiple logistic regressions. Variables included in the final multiple regression model were used to define a three-level risk stratification strategy. RESULTS: One-hundred and ten patients were included in the analysis. Univariate relationships were identified between malignancy and age, tumour size, deep fascia involvement, neurovascular involvement, necrosis, haemorrhage, oedema and heterogeneous enhancement (all P < 0.01). Final multiple regression modelling included size, enhancement and oedema. Thirty of 40 (75%) tumours >5 cm with surrounding oedema ('high risk') were malignant, 13 of 47 (28%) tumours with one or more of tumour size >5 cm, surrounding oedema or heterogeneous enhancement ('moderate risk') were malignant, and none of the 16 tumours ≤5 cm with the absence of surrounding oedema and heterogeneous enhancement ('low risk') were malignant. CONCLUSIONS: A model including tumour size, enhancement and oedema has potential to stratify soft-tissue tumours into high-, intermediate- and low-risk categories; this may inform decisions surrounding biopsy and follow-up imaging.