[Classification of hemodynamic changes in renal artery stenosis using cine magnetic resonance phase contrast flow measurements].
OBJECTIVE
To evaluate the use of high-temporal resolution cine MR phase-contrast flow measurements for assessment of flow dynamics in renal artery stenosis (RAS).


METHODS
In a dog model, cine MR flow measurements were validated by comparing the MR flow data to an invasive transit-time ultrasound reference technique for different degrees of RAS. Cardiac-gated MR flow curves were recorded in 56 renal arteries of 28 patients with a temporal resolution of at least 32 ms. In all cases RAS was confirmed by digital subtraction angiography (DSA). Abnormalities of flow dynamics were assessed in the calculated flow curves using the MR parameters mean flow, maximum velocity, and time to systolic maximum.


RESULTS
By means of the MR blood flow parameters high-grade stenoses (> 50%, n = 23) were detected with sensitivity of 100% and specificity of 94% with reference to DSA. The overall differentiation between stenoses (n = 37) and non-stenosed vessels (n = 19) revealed a sensitivity of 87% and a specificity of 100%.


CONCLUSIONS
Analysis of cardiac-gated MR flow curves provides a non-invasive method to assess the hemodynamic significance of RAS and thus allows a functional evaluation in relation to the morphologic characteristics of the stenosis.
Schoenberg
S O
SO
Deutsches Krebsforschungszentrum (DKFZ), Abteilung Radiologische Diagnostik und Therapie, Heidelberg.
Knopp
M V
MV
Bock
M
M
Kallinowski
F
F
Just
A
A
Essig
M
M
Hawighorst
H
H
Zuna
I
I
Schad
L
L
Allenberg
J R
JR
van Kaick
G
G
D000293:Adolescent; D000328:Adult; D000368:Aged; D015901:Angiography, Digital Subtraction; D000818:Animals; D001783:Blood Flow Velocity / Q000502:physiology; D004285:Dogs; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation*; D007511:Ischemia / Q000145:classification / Q000175:diagnosis / Q000503:physiopathology; D007668:Kidney / Q000098:blood supply; D019028:Magnetic Resonance Imaging, Cine / Q000295:instrumentation*; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012078:Renal Artery Obstruction / Q000145:classification / Q000175:diagnosis* / Q000503:physiopathology; D012680:Sensitivity and Specificity