The added value of ZTE MRI in the assessment of diabetic foot disease

Objectives: To analyze the added value of Zero Echo Time (ZTE) MRI compared with a standard MRI protocol in detecting osseous alterations in diabetic foot. To compare ZTE performance with CT for detecting osseous abnormalities and to evaluate inter-observer reproducibility using Cohen’s kappa coefficient. Materials and methods: This retrospective study included 46 patients (33 men, 13 women; median age, 64 years) with clinically confirmed diabetes mellitus and clinically suspected diabetic foot complications. A standard MRI protocol including a ZTE sequence was performed in all patients; all patients also underwent CT for comparison. Three readers (two radiologists and one radiology resident) independently assessed image quality and osseous abnormalities, including bone erosions, bone and soft tissue pneumatosis, dislocations, and sclerosis. Sensitivity, specificity, accuracy, and inter-observer agreement (Cohen’s κ) were calculated. Results: ZTE demonstrated superior detection in almost all osseous alterations compared with the standard MRI protocol, with the exception of bone exposure and erosions, where performance was comparable. Image quality of ZTE was rated as good to excellent in the majority of examinations. Inter-observer agreement for ZTE was excellent between the two musculoskeletal radiologists and ranged from moderate to excellent between the senior radiologist and the resident. ZTE showed high concordance with CT for detection of bone abnormalities. Conclusion: ZTE significantly improves detection of osseous alterations in diabetic foot, even under suboptimal imaging conditions. Its high image quality and strong inter-reader agreement support integration into standard MRI protocols for improved bone assessment.