Scan optimization of gadolinium contrast-enhanced three-dimensional MRA ofperipheral arteries with multiple bolus injections and in vitro validationof stenosis quantification

In this study, a T-1-weighted three-dimensional (3D) spoiled gradient-echo scanning protocol was developed to image the complete arterial system of th e pelvis and both legs along their entire length in patients with periphera l arterial disease. Three adjacent stations were to be acquired consecutive ly, with some overlap, to image the entire area of interest; per station on e gadolinium (Gd) contrast bolus would be administered. In an in vitro phan tom study, the scanning protocol was optimized. The optimal hip angle was f ound to be 50 degrees. Also, the optimal scan delay was chosen to be equal to the arrival time of the contrast bolus, thereby minimizing artifacts. Th ree contrast bolus injections showed sufficient enhancement of the vessels after image subtraction. Finally, stenosis quantification by manual caliper was performed by five observers in the magnetic resonance angiography (MRA ) images and correlated with the percent diameter reduction determined by q uantitative angiography from corresponding X-ray images. The MRA measuremen ts were reproducible, and intra- and interobserver variabilities were stati stically non-significant (p = 0.54 and p = 0.12, respectively). Stenosis qu antification performed by four observers showed a good correlation with the X-ray-derived values (r(p) > 0.90,p < 0.02); the results from one observer were not significantly correlated. Five patients with proven peripheral di sease were investigated with this new MRA scanning protocol, using standard hardware and software. The images were of good quality, which allowed adeq uate clinical evaluation; the original diagnoses obtained from X-ray examin ations, were confirmed with MRA, In conclusion, peripheral arterial disease can be evaluated adequately with this magnetic resonance scanning protocol . (C) 1998 Elsevier Science Inc.