Learning objectives
By seeing this presentation,
you can learn that the SILENT MRA is,
Magnetic resonance angiography based on a Silenz algorithm.
Because the Silenz algorithm acquires data just after RF-pulse excitation ;ultrashort echo time: UTE ,
susceptibility or dephasing artifact is reduced.
To visualize a blood flow,
in an algorithm,
uses an arterial-spin-labeling (ASL) technique as preparation pulse,
and UTE by 3D radial sampling for data acquisition.
Based on the above mentioned algorithm,
ultrashort TE helps decrease the susceptibility artifact from a metallic implants,
visualization of...
Background
TOF-MRA is,
Based on the principle of flow related enhancement,
and since flow signal is sensitive to saturation effects,
slow flow can be difficult to clearly visualize.
In addition,
faster,
or turbulent flow,
may cause a loss of signal or a vessel parallel to the scan-plane may result in signal loss from the vessel.
Visualizing flow means visualizing arterial geometry and patency.
SILENT MRA is,
Insensitive for saturation effects and it helps to visualize a vessel,
even when the flow is moving slowly,
regardless of...
Findings and procedure details
SCAN PROTOCOL
MRAs were scanned in the same session on 3T unit (Discovery MR750w 3.0T,
GE Healthcare,
Milwaukee,
WI,
U.S.A.).
Silent MRA: TR/TE,
1116.4/0.016 msec; flip angle,
5°; field of view,
180×180 mm; matrix,
150×150; section thickness,
1.2 mm; number of excitations (NEX),
1.5; band width,
±20 kHz; and acquisition time,
7 min 40 s.
TOF MRAs : TR/TE,
19/2.9 msec; flip angle,
15°; field of view,
200×200 mm; matrix,
416×192; section thickness,
1.2 mm; NEX,
1; band width,
±41.7 kHz; and acquisition time,
3...
Conclusion
Hereby,
a clinical feasibility of SILENT-MRA was provided through some cases.UTE helps decrease the susceptibility artifact from a metallic implants,visualization of small flow signal change with the ASL methoda subtraction of the static tissue in the raw data.
There is a possibility that SILENT-MRA can express the 'real flow' compared with TOF-MRA.
References
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F.,
et al.,
MR angiography with ultrashort echo time in cerebral aneurysms treated...