Low dose pedal magnetic resonance angiography at 3 Tesla with time-resolved imaging of contrast kinetics - A feasibility study

Objectives: To assess the feasibility of low-dose time-resolved imaging of contrast kinetics (TRICKS) magnetic resonance (MR) angiography of the pedal vasculature at 3.0 Tesla (T) using a head coil. Materials and Methods: Eleven healthy volunteers were imaged using TRICKS MR angiography at 3.0 T with both feet positioned in a head coil. A dose of 7 mL was used for each of 3 acquisitions: images were obtained of each foot in the sagittal plane, and then both feet were imaged simultaneously in the transverse plane. The following parameters were used for acquisition: (TR/TE 4.7 milliseconds/1.3 milliseconds, field of view = 28 cm, Flip angle = 30 degrees, 384 X 256 matrix, section thickness = 1.6 mm, Bandwidth = 19.23). The dorsalis pedis, plantar arch, distal posterior tibial, lateral tarsal, and medial plantar arteries were graded for visualization, artifact, and overall image quality on a 4-point scale (I = worst; 4 = best). Results: Superior visualization trended towards separate sagittal acquisitions when compared with that of bilateral transverse acquisitions for most of the individual vessels of the foot. Overall, separate sagittal acquisitions (average score = 2.9) were superior to bilateral transverse acquisitions (average score = 2.6). The average image quality score reflecting the amount of artifact was 2.6 for studies obtained using bilateral transverse acquisitions and 3.1 for studies obtained using separate sagittal acquisitions. Conclusion: Low-dose gadolinium multi-injection TRICKS and bolus-chase MR angiography at 3.0 T provides an effective and easily reproducible technique for imaging of the pedal vasculature in volunteers and has great potential for clinical application.