Repeatability Of Lower Extremities Angiography Using The Flow Spoiled-Fresh Blood Imaging(FS-FBI)

Purpose: To prospectively evaluate the repeatability of non-contrast enhanced lower extremities angiography using the flow spoiled-fresh blood imaging(FS-FBI).Methods: Forty three healthy volunteers(20 men and 23 women; mean age 24.3±2.3 years, age range from19 to 34 years)and thirteen patients with lower extremity arterial disease(7 men and 6 women; mean age 54.7±9.6 years, age range from 20 to 67 years) were recruited in this study and were examined by FS-FBI lower extremities angiography in a 1.5T MR scanner. Each subject was examined twice for a median of one week. The two sections of legs were examined using the automatic table moving technology. Repeatability was assessed for the two following major parameters by two independent observers: 1) evaluation of image quality based on three grades; 2) value of artery diameter and area of arteries(overall 14 arteries per person, including bilateral common femoral artery, superficial femoral artery, deep femoral artery, popliteal artery, anterior tibial artery, posterior tibial artery and peroneal artery). Maximum intensity projection(MIP) and multiple planar reformation(MPR) were constructed by the post-processing workstation. The widest caliber was measured perpendicular to its long axis as the diameter of the artery. Inter- and intra-observer intraclass correlation coefficients(ICCs) was used for statistical analysis.Results: Among the 43 volunteers, at least 93.0% were scored 1 by two observers and the minimum intra-observer ICC was 0.918 for the femoral segment. In the popliteocrural segment, both observers grade score 1 in 96.5% of all the volunteers, and the minimum intra-observer ICC was 1.000. In the patients group, at least 84.6% were scored 1 by two observers and the minimum intra-observer ICC was 0.874 for the femoral segment. In the popliteocrural segment, both observers grade score 1 in 69.2% of all the patients, and the minimum intra-observer ICC was 0.921. For measurements of both diameter and area of arteries, the minimum inter- and intra-observer ICC was 0.821 and 0.727 respectively for the femoral segment, and 0.773 and 0.726 respectively for the popliteocrural segment.Conclusion: FS-FBI non-contrast-enhanced imaging techniques can be a good indication of lower limb arteries normal volunteers and patients, having a high reproducibility in the demonstration of lower extremity arterial diameter and area in normal volunteers.