Purpose
Introduction
To increase spatial resolution in Multi-slice CT (MSCT) scan lead to the suggestion that it is clinically useful of recognizing the visibility of micro-vessel in CT angiography.
However,
image noise increases due to increase spatial resolution in MSCT.
256-slice MSCT (Brilliance iCT,
Philips healthcare) is equipped with three different resolution modes Standard Resolution mode (large focus scan),
High Resolution (small focus scan) and Ultra High Resolution (UHR) mode.
UHR mode uses a small focus with Ultra High Resolution Collimator.
(Fig.1) Each resolution mode has...
Methods and Materials
CT scan was performed at three different resolution modes: Standard resolution mode,
High resolution mode and UHR mode with IR using a 256-slice MSCT (Brilliance iCT,
Philips healthcare). A vessel phantom was made by modifying a Japanese Industrial Standard CT Quality Assurance phantom (3D Sphere Phantom; Kyoto Kagaku) with simulated vessels of 0.4mm,
0.5mm,
0,7mm and 1.0mmdiameter.
The phantom was scanned at the three scan modes with intra-vessel attenuation of 400 HU (filled with iodine contrast medium).
As for 3D Sphere Phantom (Kyoto Kagaku),
the...
Results
Result1
The minimum vessel diameter detected in MPR imaging with standard resolution is 1.0mm.
Comparing IR images to FBP images,
the difference of both images did not affect visibility.
The same result was shown with increasing IR level.
All readers' score was the same.
(Fig.7)
In case of High Resolution mode,
the minimum vessel diameter detected is 0.7mm.Comparing IR images to FBP images,
the difference of both images did not affect visibility.
The same result was shown even increasing IR level.
All readers' score was...
Conclusion
Conclusion
The UHR mode in 256-slice MSCT (Brilliance iCT,
Philips healthcare) is able to detect of sub-millimeter vessels.
Detectability of sub-millimeter vessels improves using UHR mode in combination with IR.IR is especially effective in improving the visibility of VR imaging.
Acknowledgment
I am deeply grateful to Mr.Nobuyuki Niwa(Kyoto kagaku) & Mr.Haibin Huang(PHILIPS Healthcare).
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Personal Information
Taisuke Fujioka
Radiographer.
Department of CT Application,
Philips Electronics Japan,Ltd.
Minato-ku.Tokyo.Japan.
E-mail:
[email protected]