Inclusion Criteria:  Patients over 18 years of age Performing an MRI injected as part of care for one of the following reasons: suspicion of pathology likely to be associated with narrowing or obstruction of one or more venous sinuses (cerebral thrombophlebitis, tissue damage with venous extension, idiopathic HIC venous narrowing or obstruction proven by one of the above pathologies, requiring as part of routine care an injected MRI (search for impact, monitoring, pre-therapeutic assessment or prognosis) Express consent to participate in the study Affiliate or beneficiary of a social security scheme  Exclusion Criteria:  Absolute contraindication to MRI Patient benefiting from a legal protection measure Pregnant or breastfeeding woman