[Magnetic resonance angiographic occlusion of the cervical carotid artery at 3 tesla: its pitfalls].

Magnetic resonance angiography (MRA) is one of the most popular tools for imaging cerebral arteries. However, it may overestimate steno-occlusive lesions. The purpose of the present study was to investigate the diagnostic accuracy of cervical MRA for carotid steno-occlusive lesions. This study included 13 sides of 12 patients (male: female = 11: 1, 53-83 years old) who showed cervical carotid occlusion on MRA at 3 tesla. The MRA was performed along with time-resolved imaging of contrast kinetics (TRICKS) and/or black blood imaging (BBI) when detailed evaluation was considered necessary after routine 1.5 tesla MRA. All patients underwent digital subtraction angiography (DSA) for definitive diagnosis. Cervical duplex scan was also performed in 12 sides. DSA demonstrated occlusion in only 6 sides (46.2%). In the remaining 7 sides, in spite of occlusion on MRA, DSA demonstrated stenoses in 4 sides and pseudoocclusions in 3 sides. Adding TRICKS or BBI resulted in correct diagnosis (same as DSA) in 6 sides. In comparison to DSA, sensitivity and specificity of combination of TRICKS and BBI were 100% and 85.7%, respectively, for the diagnosis of cervical carotid occlusion. In conclusion, MRA alone does not accurately demonstrate severe stenosis of the cervical carotid artery and may miss surgical candidates. TRICKS and BBI are useful adjunct tools for an accurate diagnosis.