Insights of cartilage imaging in cartilage regeneration

Cartilage, as a specialized connective tissue, underpins joint mobility and mechanical load distribution while exhibiting inherently limited self-repair capabilities. This comprehensive review redefines the current landscape of cartilage imaging by exploring conventional and advanced modalities used to assess both the structural and biochemical attributes of cartilage. Whereas conventional radiography and ultrasound offer rudimentary, indirect assessments, cutting-edge techniques - including magnetic resonance imaging (MRI)-based sequences such as T2 mapping, delayed gadolinium-enhanced MRI of cartilage, and sodium MRI - enable early detection of molecular alterations in the cartilage matrix. In addition, hybrid approaches like positron emission tomography-MRI are emerging to provide integrative molecular and structural insights. This article critically appraises imaging strategies in the context of regenerative interventions, highlighting technical innovations, persistent challenges, and future directions to facilitate improved diagnostic accuracy and therapeutic monitoring.