Contrast-enhanced 3D MRA with centric ordering in k space: A preliminary clinical experience in imaging the abdominal aorta and renal and peripheral arterial vasculature

The objective of this study was to determine the clinical utility of a cont rast-enhanced, centric reordered, three-dimensional (3D) MR angiography (MR A) pulse sequence in imaging the abdominal aorta and renal and peripheral l ower extremity arteries. Twenty-eight MRA studies were performed on 23 pati ents and four volunteers at 1.5 T using a 3D contrast-enhanced, centric reo rdered pulse sequence. In 20 patients, the abdominal aorta and renal arteri es were imaged, and in seven patients, the lower extremity arteries were im aged. In 19 patients, a total of 51 renal vessels were evaluated (33 renal arteries using .1 mmol/kg of gadopentetate dimeglumine and 18 renal arterie s using .2 mmol/kg of gadoteridol). A total of 70 peripheral arterial segme nts were assessed using .2 mmol/kg of gadoteridol, Correlation with convent ional angiography was made for the following 14 cases: renal artery stenosi s (four cases), abdominal aortic stenosis (one case), arteriovenous fistula in a transplant kidney (one case), renal arteriovenous malformation (one c ase), common iliac artery aneurysms (one case), and peripheral lower extrem ity (six cases). Of the 70 peripheral arterial segments evaluated, in 35, t here was correlation with xray angiography, The mean percent of aortic sign al enhancement was significantly higher in the .2 mmol/kg dose group (370.8 +/- 190.3) than in the .1 mmol/kg dose group (184.5 +/- 128.9) (P = .02), However, there was no apparent difference between the two doses for visuali zation of the renal and accessory renal arteries, There was concordance bet ween the contrast-enhanced 3D MRA studies and conventional angiography in a ll cases of renal artery and peripheral arterial stenoses and occlusions, i ncluding visualization of reconstituted peripheral arterial segments. There was no evidence of spin dephasing effects at sites of stenoses on the 3D c ontrast-enhanced MRA studies. Contrast-enhanced, centric reordered, 3D MRA can rapidly image the abdominal aorta and renal and accessory renal arterie s, as well as peripheral lower extremity arteries, with high resolution. Ac curate depiction of the vascular lumen at sites of stenosis is made because of the lack of spin dephasing effects, even with hemodynamically significa nt stenoses. Additional larger clinical trials are required with this promi sing technique.