Magnetic resonance flow measurements in real time: comparison with a standard gradient-echo technique.
Ultrafast gradient systems and hybrid imaging sequences offer the opportunity to acquire phase contrast flow data in real time. In a 1.5-Tesla magnetic resonance (MR)-tomograph, peak velocity and volume flow were assessed in 36 large vessels (aorta) and 33 medium-sized vessels (carotid and iliac artery) using a real-time (segmented k-space turbo gradient-echo planar imaging sequence) in comparison with a gradient-echo technique. With the real-time technique, the matrix was reduced from 116 to 64, and temporal resolution changed from 30 msec to 124 msec. Measurements of peak velocity correlated in large (r = 0.88) and medium-sized vessels (r = 0.81). Volume flow measurements correlated in large vessels (r = 0.87), however, a poor correlation (r = 0.64) was found in medium-sized vessels. Thus, scan time can be significantly reduced and images acquired without electrocardiogram (ECG)-triggering. Flow volume can only be determined in large vessels with sufficient accuracy, mainly due to reduced spatial resolution in smaller vessels.
Klein
C
C
Department of Internal Medicine/Cardiology, German Heart Institute Berlin, Humboldt University, Augustenburger Platz 1, D-13353 Berlin, Germany.
Schalla
S
S
Schnackenburg
B
B
Bornstedt
A
A
Fleck
E
E
Nagel
E
E
D001783:Blood Flow Velocity; D001808:Blood Vessels / Q000033:anatomy & histology* / Q000502:physiology; D001810:Blood Volume; D003199:Computer Systems; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012015:Reference Standards