Renal artery stenosis: grading of hemodynamic changes with cine phase-contrast MR blood flow measurements.
OBJECTIVE
To analyze the blood flow dynamics in renal artery stenosis with high-temporal-resolution cine phase-contrast magnetic resonance (MR) flow measurements.


METHODS
Cine phase-contrast MR flow measurements were invasively validated with real-time intraoperative transit-time ultrasound (US). In 23 patients, 48 renal artery stenoses were confirmed at digital subtraction angiography. Cardiac-gated cine phase-contrast MR flow measurements were obtained in 32-msec intervals, and flow curves were calculated for the whole cardiac cycle. Hemodynamic parameters evaluated included the decrease in mean flow and the delay and reduction in the systolic velocity maximum due to decrease in or absence of the early systolic peak.


RESULTS
Overall differentiation between renal artery stenosis (n = 31) and nonstenosed vessels (n = 17) with cine phase-contrast MR revealed a sensitivity of 90% and specificity of 94% compared with findings at digital subtraction angiography. High-grade stenoses (>50%, n = 19) were detected with cine phase-contrast MR with sensitivity of 100% and specificity of 93%.


CONCLUSIONS
Quantitative and qualitative analysis of cardiac-gated cine phase-contrast MR flow velocity curves provided a highly accurate method to detect hemodynamic abnormalities in patients with suspected renal artery stenosis.
Schoenberg
S O
SO
Department of Radiology, German Cancer Research Center, Heidelberg.
Knopp
M V
MV
Bock
M
M
Kallinowski
F
F
Just
A
A
Essig
M
M
Hawighorst
H
H
Schad
L
L
van Kaick
G
G
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015901:Angiography, Digital Subtraction; D000818:Animals; D001783:Blood Flow Velocity; D004285:Dogs; D005260:Female; D006439:Hemodynamics; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012077:Renal Artery / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D012078:Renal Artery Obstruction / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D012680:Sensitivity and Specificity