MRI of soft tissue tumours: a structured "8S framework" aligned with WHO 2020 classification

Soft tissue tumours (STTs) encompass a wide spectrum of benign, intermediate, and malignant lesions, often posing significant diagnostic and management challenges. Magnetic resonance imaging (MRI) offers excellent soft tissue characterization, but non-specific clinical presentation, overlapping MRI features, and wide histological variability of soft tissue tumours limit the predictive value of MRI. This review article presents a novel 8S framework that integrates MRI features of morphology, function, and biological aggressiveness to enhance diagnostic precision and risk stratification. The approach evaluates Site, Size, Shape/Surface, Signal, Surroundings, Sequence behaviour, Surgical assistance, and Satellites/Skips detailing tumour anatomy and internal structure while focusing on biological aggressiveness, incorporating dynamic contrast enhancement, diffusion characteristics, and patterns of local invasion as well as metastatic potential. The framework represents a clinically actionable MRI strategy. By aligning the 8S framework with the 2020 WHO soft tissue tumour classification, this approach enables differentiation of benign, locally aggressive, and high-grade malignant tumours, guiding biopsy, surgical planning, and prognosis.