Contrast-enhanced carotid magnetic resonance angiography: comparison of single-dose and double-dose of gadolinium using the randomly segmented central k-space ordering technique.

Background: The aim of this study was to evaluate whether the single dose of gadolinium is sufficient for contrast-enhanced magnetic resonance angiography (MRA) of carotid arteries with the use of newly developed randomly segmented central k-space ordering technique called contrast-enhanced timing-robust angiography (CENTRA).

Methods: A total of 44 patients underwent carotid MRA in a 1.5T MR scanner using a fluoroscopically monitored, manually triggered, CENTRA pulse sequence. Patients were randomly assigned into two groups according to the dose of contrast medium (gadolinium chelate) administered: group 1 referred to those who received double doses (0.2 mmol/kg) and group 2 received single doses (0.1 mmol/kg). The contrast-to-noise (CNR) ratios of the seven regions of interest were calculated. The delineation of nine vascular regions and the degree of venous overlay were evaluated by two blinded readers on a five-point scale.

Results: For quantitative evaluation, the CNRs at the brachiocephalic artery were greater in patients in group 1 than that in group 2 (p = 0.015), while the differences did not differ between the two groups for the remaining regions of interest (p > 0.05). For qualitative evaluation, there were no significant differences between the two groups in delineation of nine vascular regions and venous overlaying (p > 0.05).

Conclusion: With the use of the CENTRA technique, carotid MRA may be performed using a single dose of gadolinium and the image quality is comparable to that of the standard double dose protocol.