Keywords:
Arteries / Aorta, Cardiovascular system, Vascular, MR-Angiography, Diagnostic procedure
Authors:
A. Fischer, S. Orzada, S. Johst, M. E. Ladd, K. Nassenstein, T. Lauenstein, S. Maderwald; Essen/DE
DOI:
10.1594/ecr2013/C-2343
Results
T1w FLASH imaging at 7 Tesla provided a hyperintense artery signal in the iliac,
femoral,
popliteal,
and lower leg artery segments without application of contrast agent.
The large arterial vasculature of the pelvis and lower extremity as well as small pedal and intramuscular arteries could be delineated nicely (Fig.
3).
Qualitative analysis showed a superiority for the TurboFLASH sequence for all analyzed artery segments despite the iliacal one with good to excellent image quality (Fig.
4).
Best image quality was found for the popliteal segment.
Regarding the presence of artifacts,
TurboFLASH was superior in all artery segments (Fig.
4).
2D FLASH without gating showed strong flow artifacts and blurring of the vessel wall (Fig.
5),
which could be reduced using the phonocardiogram-gated TubroFLASH sequence.
The superficial femoral artery showed a considerable signal loss in the middle of the thigh,
although it offered a highly hyperintense and sharply defined signal in the upper and lower thigh segment (Fig.
6).
This can be due to RF interferences (inadequate flip angle) in the variable anatomy of pelvis and legs along the longitudinal axis.
Transformation of the axial source images into coronal MIP images revealed an artifact characterized by short,
periodic declines of artery signal and blurring of the vessel wall with maximal appearance in the lower thigh and calves (Fig.
7,
arrows).
These signal drops are suspected to arise due to an interference between alternating vessel pressure and flow effects during systole and diastole and could be considerably reduced during PCG-gated TurboFLASH imaging (Fig.
7).
Analysis of Contrast Ratios showed similar values for both sequences due to an equal supression of background signal (Fig.
8).