METHOD FOR DIAGNOSING BRACHIOCEPHALIC VEIN OBSTRUCTION Russian patent published in 2001 - IPC

FIELD: medicine. SUBSTANCE: method involves carrying out two-dimensional, time interval magnetic resonance venography with transversely oriented slices. MIP program is used for processing the venograms by rebuilding magnetic resonance - venograms and studying changes in blood circulation magnetic resonance signals. Ultrasonic color duplex scanning of internal jugular veins in axial and sagittal planes with mean linear blood circulation flow rate and mean volume rate being determined. Venous angle of nameless vein bifurcation is determined from magnetic resonance venograms. The calculated blood circulation flow rates are compared to norm for the given venous bifurcation angle and magnetic resonance signal change patterns are built in more details. Vein boundaries, the degree of transverse deformation of a vein, blood circulation signal intensity pattern, compressing agents and the type of their action upon the injured vein and the degree of compensatory dilation of healthy vein collectors are determined from slices. Hemodynamically significant brachiocephalic vein obstruction is diagnosed when a set of the following symptoms is available. Local reduction of diameter and vein cross-section with its transverse profile being deformed takes place, linear blood circulation flow rate is increased by 40-45% at the maximum compression segment, contralateral internal jugular vein is 3-11 times dilated when compared to compressed vein, other vein collectors are dilated, compressed vein diameter is reduced proximally to compression level, injured vein signal intensity becomes lower at the max compression place and proximal to compression area in some interval, volume blood circulation rate is 3-8 times reduced in compressed vein. Magnetic resonance venography is carried out using tomograph device at magnetic field intensity being equal to 0.2 Tesla units with 60-64 slices made with slice thickness of 3-4 mm, repetition interval TR=100 ms, echo time TE=14 ms, intensity vector deviation angle FA= 60 deg, vision field being equal to 125x250 and 10% of slices superposition. EFFECT: enhanced accuracy of diagnosis; low costs of examination. 2 cl