CAROTID AND VERTEBRAL ARTERY DISSECTIONS - EXAMINATION STRATEGIES IN MR-IMAGING AND MR-ANGIOGRAPHY

Purpose: To define the diagnostic efficacy of MR imaging, ''time of fl ight'' (TOF) and phase contrast (PC) MR angiography in craniocervical arterial dissections. Material and methods: The MR examinations of 16 patients with proven arterial dissections (n = 20) were retrospectivel y analysed by three independent readers. The MR protocol included T1W spin echo sequences with and without fat saturation (SPIR), T2W-turbo- spin echo, 2D- and 3D-TOF- and 3D-PC-MRA. The study was undertaken to assess the diagnostic sensitivity of each technique in detecting typic al pathological features. Results: The overall sensitivity was best in 3D-PC-MRA; reaching 88% of all possible points. Intramural haematoma could be easily detected with T1W spin echo with fat saturation (100%) . Intimal flap and lumen narrowing was best defined with 3D-TOF-MRA in 86% resp. 96% and 3D-PC-MRA in 69% resp. 97%. 3D-PC-MRA was superior to all other sequences in 5 cases of aneurysmal dissection (100%). Con clusions: An accurate evaluation of craniocervical arterial dissection s should rely on a combined protocol including T1W spin echo with fat saturation and an axial 3D-MR angiography (if possible 3D-phase contra st MRA).