3.0T contrast-enhanced, submilimeter MRA of the supraaortic arteries: does the signal gain at high field strength allow to replace the phased array coil by the quadrature body coil?

Purpose of the study was to evaluate contrast-enhanced MR angiography (CE MRA) of the supraaortic arteries at 3.0T using the quadrature body coil as transmitter and receiver. CE MRA was performed with randomly segmented central k-space ordering (CENTRA) in 43 patients and 5 volunteers using a large FOV (350 mm) and a high image matrix of 432 x 432 (nonzerofilled voxel: 0.66 mm3).Our experience showed that submillimeter CE MRA of the supraaortic arteries is feasible at 3.0T by using the quadrature body coil. The large FOV allowed to cover the supraaortic arteries from the aortic arch up to the circle of Willis. Introduction Contrast-enhanced 3D MR angiography of the supraaortic arteries with randomly segmented k-space ordering (CENTRA) has proved to provide reliable arterial phase images with high spatial resolution (512 and 1024 matrix) and high degree of venous suppression [1,2]. As CENTRA allows k-space sampling both during the upslope and tail of the contrast-time curve, acquisition times of up to 2 minutes and more are feasible without image degradation by venous enhancement. In addition, this technique has shown high diagnostic accuracy for detection of supraaortic artery disease as compared with DSA [2]. However, specific phased-array neurovascular coils were required to allow submillimeter resolution at 1.5T With the advent of compact, actively shielded 3.0T magnets, high field imaging has become practical in a clinical setting. As the singal scales proportionally with the field strength, 3.0T holds potential benefits for high resolution MRA [3,4]. However, large FOV imaging at high magnetic field is challeging due to the increased susceptibilty and the field inhomogeneties. In CE MRA of the supraaortic arteries, we examined whether the the increased signal-to-noise (S/N) available at 3.0T would allow to replace the phased-array neurovascular coil by the standard quadrature body coil while maintaining the high spatial resolution and whether the large FOV that was used in our routine 1.5T protocol would be feasible also at 3.0T.