Arterial head vascularization cartographies of normal metencephalic dogs using magnetic resonance angiography.

The aim of our study was to establish head arterial cartographies-useful for the diagnosis of brain diseases leading to cerebral vascular modifications-by means of magnetic resonance angiography (MRA). Casts of the arterial vascular brain system were used to corroborate the MRA results as they can be easily rotated in nonvirtual three-dimensions and give an accurate view of the arteries calibre and origin. Two types of 3T MRA images were used: three-dimensional fast low-angle shot (3D-FLASH) acquisition sequenced every 20 s, paired with injection of a paramagnetic contrast medium, and three-dimensional time-of-flight (3D-TOF) acquisition sequenced every 300 s. 3D-FLASH acquisition gives very accurate images of the cerebral arteries and veins, but must be used with care in debilitated animals. 3D-TOF acquisition is less accurate and gives only images of the main cerebral arteries without showing the venous system. It is, however, a viable diagnostic method for monitoring vascular lesions (e.g., cerebral hemorrhages).