Magnetic resonance angiography of the origins of the supraaortic arteries: comparison of single and double volume acquisition 3D time of flight.

PURPOSE

The authors have optimized the technique of Magnetic Resonance Angiography (MR-angio) in the study of the origins of the supraaortic arteries.

METHODS

Twenty healthy volunteers, mean age 21.5, were studied with MR-angio of the origins of the supraaortic arteries; a 1 T superconductive magnet (Impact) with body coil was used. All the volunteers were studied using Time of flight (TOF), and two acquisition techniques: single volume FISP (fast imaging with steady-state precession) 3D TONE (titled optimized non-saturating excitation) and double volume FISP 3D TONE with 30% overlapping. The images were acquired on the axial plane following the positioning of three pre-saturation pulses.

RESULTS

Regarding the visualization of the different components of the origins of the supraaortic arteries, a statistical analysis was worked out using the Mann Whitney test (p < 0.05); there was no statistically significant difference between two techniques. Regarding the visualization of the various segments (origin, 1/3 proximal, 1/3 middle, 1/3 distal), although the double volume did on the one hand allow a better visualization of the more distal vascular components (statiscally significant difference), on the other it induced the presence of artefacts with decreased the quality of the image as a whole.

DISCUSSION

In our experience TOF 3D technique with TONE and single volume has well identified the origin of the vertebral arteries, while, in several cases, TOF 3D technique with TONE and double volume did not permit the visualization of the origin of the vertebral arteries due to the presence of the artefacts from overlapping.

CONCLUSION

From our experience we have established that the TOF 3D technique with TONE and single volume makes it possible to obtain MR-angio of a high diagnostic quality in a short time (10-15 mn).