Correlation of femoral artery flow velocity waveform with ipsilateral iliac artery stenoses assessed with magnetic resonance imaging.
BACKGROUND
Magnetic resonance (MR) permits quantitative flow velocity measurements that could be used to detect changes in the curve profile downstream of a high-grade stenosis.


OBJECTIVE
To assess whether MR flow measurements can be used to detect iliac artery stenoses.


METHODS
Contrast-enhanced magnetic resonance angiography (MRA) and quantitative flow measurements in the lower aorta and proximal femoral arteries were performed in 29 patients with suspected iliac artery stenoses. Stenoses were graded into five degrees: 0%, 1-49%, 50-74%, 75-99%, and 100% diameter reduction. The femoral artery waveforms were evaluated qualitatively by two independent reviewers regarding peak systolic velocity (PSV), aortofemoral difference in time-to-peak (DeltaTTP), systolic acceleration (SA), curve-shape index (CSI), and the presence of an early diastolic flow reversal. The correlation between these parameters and the degree of stenosis was assessed.


RESULTS
A significant correlation with degree of stenosis was observed for the qualitative flow waveform evaluations, with a high degree of interobserver agreement (kappa = 0.84). A significant correlation was also found between degree of stenosis and PSV, DeltaTTP, SA, CSI, and presence of diastolic flow reversal. The flow velocity pattern, however, remained unchanged, both qualitatively and quantitatively, up to a stenosis degree of at least 75%.


CONCLUSIONS
Iliac artery stenoses cause femoral artery flow waveform changes that can be detected with MRI, but only at high-grade levels.
Wikström
J
J
Department of Radiology, Uppsala University Hospital, Uppsala, Sweden. johan.wikstrom@radiol.uu.se
Johansson
L
L
Karacagil
S
S
Ahlström
H
H
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001012:Aorta, Abdominal / Q000503:physiopathology; D001783:Blood Flow Velocity / Q000502:physiology; D003251:Constriction, Pathologic / Q000145:classification / Q000503:physiopathology; D003287:Contrast Media; D003971:Diastole / Q000502:physiology; D005260:Female; D005263:Femoral Artery / Q000503:physiopathology*; D005682:Gadolinium; D006801:Humans; D007083:Iliac Artery / Q000503:physiopathology*; D018810:Magnetic Resonance Angiography; D008297:Male; D008536:Meglumine / Q000031:analogs & derivatives; D008875:Middle Aged; D015588:Observer Variation; D009942:Organometallic Compounds; D016491:Peripheral Vascular Diseases / Q000145:classification / Q000503:physiopathology*; D012680:Sensitivity and Specificity; D013599:Systole / Q000502:physiology; D013997:Time Factors
D003287:Contrast Media; D009942:Organometallic Compounds; C064572:gadobenic acid; D008536:Meglumine; D005682:Gadolinium