Doppler Sonography, MR Venography, Plethysmography for the Diagnosis of CCSVI

1. Patients group Inclusion Criteria: * confirmed diagnosis of multiple sclerosis Exclusion Criteria: * coexisting another neurologic pathology (e.g. stroke, Parkinson disease) * significant stenosis of carotid or vertebral arteries * other significant abnormalities of blood vessels of the upper part of the body * tricuspid valve incompetence * allergy to iodine contrast dye * chronic renal failure * pregnancy * other severe comorbidities or significant abnormalities in standard lab tests 2. Healthy volunteers. Inclusion Criteria: * none Exclusion Criteria: * confirmed diagnosis of multiple sclerosis or related pathologies (CIS, NMO) * coexisting another neurologic pathology (e.g. stroke, Parkinson disease) * significant stenosis of carotid or vertebral arteries * other significant abnormalities of blood vessels of the upper part of the body * tricuspid valve incompetence