Magnetization-prepared MR angiography with fat suppression and venous saturation.
Magnetization-prepared magnetic resonance (MR) angiography (MPMRA) is an inflow-based two-dimensional (2D) imaging sequence in which a preparation phase precedes rapid image acquisition. For maximal blood/tissue contrast, an inversion-recovery preparation nulls signal from static tissue. If needed, a second inversion suppresses signal from fat. Fully magnetized blood flows in after the inversion pulse(s), providing high signal intensity. The centric phase-encoding order, which ensures that the initial contrast is reflected in the image set, requires the use of a modified venous saturation technique. The sequence is described and its performance assessed with regard to (a) depiction of in-plane flow, (b) fat suppression, and (c) venous saturation. Phantom and volunteer studies showed good performance in all three areas. MPMRA images, acquired in just 2-4 seconds per image, had a blood/tissue contrast-to-noise ratio nearly twice that of standard 2D time-of-flight MR angiograms, acquired in 5-7 seconds. The technique is promising for restless patients and in anatomic areas plagued by motion degradation.
Richardson
D B
DB
Department of Diagnostic Radiology, Mayo Clinic, Rochester, Minn.
Bampton
A E
AE
Riederer
S J
SJ
MacFall
J R
JR
D000273:Adipose Tissue; D001808:Blood Vessels / Q000033:anatomy & histology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008961:Models, Structural; D014680:Veins