MR-ANGIOGRAPHY OF THE CAROTID ARTERIES - INFLUENCE OF SHORT AND ULTRASHORT ECHO TIMES

Purpose: To evaluate the influence of short and ultrashort echo times (T-E) on the magnetic resonance (MR) signal in the carotid sinus and i n carotid artery stenoses. Material and methods: High resolution gradi ent-echo sequences without and with flow compensation using T-E's rang ing from 1.5 to 8.0 ms were compared on phantoms, eight healthy volunt eers, and 10 patients with moderate and severe carotid artery stenoses . Results: MR sequences with shortest T-E's provided the best visualis ation of stenotic regions in the carotid sinus and demonstrated a subs tantial reduction of signal loss due to spin dephasing in both phantom and patient studies. This was made possible using an improved gradien t system with higher gradient strengths and shorter rise times with lo wer acquisition bandwidths and better signal-to-noise ratio. Conclusio n: MR sequences with short and ultrashort T-E's enable a better defini tion of the stenotic region and therefore guide adequate therapeutic d ecisions.