Cartography and Quantitative Characterization of Achilles Tendon Fibrocartilage by TE = 0ms Imaging at 3T MRI

Inclusion Criteria: * Age ≥18 years, * Covered under social security * Informed signed consent Additional criteria for each group: GROUP 1: HEALTHY VOLUNTEERS * Absence of diagnosis of spondyloarthropathies * No previous history of plantar support and pain, calcaneal tendinopathy, infiltration or surgery GROUP 2: SPA + NON-SYMPTOMATICS AT THE CALCANEEN FIBROCARTILAGE LEVEL * ASAS criteria axial or appendicular * No previous history of plantar support and pain, infiltration or surgery * Prescription Achile's tendon MRI with injection of contrast agent (macrocyclic gadolinium) in usual care. GROUP 3: SPA + SYMPTOMATICS AT THE CALCANEEN FIBROCARTILAGE LEVEL * ASAS criteria axial or appendicular * Clinical suspicion of rheumatic enthesopathy * Absence of a history of calcaneal infiltration or surgery * Prescription Achile's tendon MRI with injection of contrast agent (macrocyclic gadolinium) in usual care. GROUP 4: MECHANIC TENDINOPATHY * Clinical diagnosis of calcaneal mechanical tendinopathy * Absence of diagnosis of spondyloarthropathies * No any previous history of plantar support disorder, calcaneal infiltration or surgery * Prescription Achile's tendon MRI with injection of contrast agent (macrocyclic gadolinium) in usual care. Exclusion Criteria: * Age less than 18 yrs old * Pregnant or lactating woman * History or presence coronary pathology * Septic arthritis * Immunodeficiency. * Contra-indication for MRI exam * Legal protection Additional criteria for GROU…