Magnetic resonance imaging, magnetic resonance and catheter angiography for diagnosis of cervical artery dissection.

Catheter angiography has been considered the standard of reference for the diagnosis of spontaneous cervical artery dissection (CAD), but carries a risk of complications and does not demonstrate the arterial wall. The most common angiographic finding is a relatively smooth or slightly irregular tapered arterial narrowing. Conversely, angiographic appearance of cervical artery occlusion due to CAD is nonspecific, because other causes such as thromboembolism or atherosclerotic disease may present very similar angiographic characteristics. Magnetic resonance imaging (MRI) is an alternative noninvasive approach and the only reliable possibility to diagnose occlusive dissection. MRI demonstrates the hyperintense, crescent- shaped wall hematoma and an eccentric flow void of the patent lumen. Intramural hematoma shows a typical evolution of signal intensity over time with intermediate signal intensity on T1-weighted images and high signal intensity on T2-weighted images in the first 3 days. In the following days, most intramural hematoma show slightly or definitively increased signal intensity on T1- and T2-weighted images. After this, signal intensity of the hematoma increases and remains high for approximately 2 months. Magnetic resonance angiography shows the same findings as catheter angiography, and allows in combination with MRI to determine the extent of CAD.