Owandy Radiology i-max touch 3D, User Manual

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User Manual
– Quality assurance program
NIMXEN020I
Owandy Radiology SAS
54
8.5.5 Spatial resolution
Click on "Next measure" button (6 - Figure 11) to proceed with the "Modulation Transfer Function"
test, which gives information about spatial resolution.
The image will be loaded automatically. Left click to place an area as shown in the sample picture
on the right panel (5 - Figure 11).
Two values are displayed, which are characteristic points of the Modulation Transfer Function
expressed in lp/mm:
•
MTF
10%
- spatial frequency at which the frequency response is 10% of the maximum
value. This value must be greater or equal to 1 lp/mm
•
MTF
50%
- spatial frequency at which the frequency response is 50% of the maximum
value.
Report the values in the "MTF 10%" and "MTF 50%" cells of the QC log book at paragraph 8.5.12.
8.5.6 CT number
Click on "Next measure" button (6 - Figure 11) to proceed with the "CT number" test, which gives
information about the CT number of the different materials within the volume.
The image will be loaded automatically, left click and drag to draw an area as shown in the
example picture on the right panel (5 - Figure 11).
The mean and standard deviation of the gray levels inside the area are displayed. The mean
value must be in the range from -100 to +100 HU.
Report this value in the "CT number" cell of the QC log book at paragraph 8.5.12.
8.5.7 Length and width measures
Click on "Next measure" button (6 - Figure 11) to proceed with the "Length and width" test, which
gives information about the geometry of the 3D reconstruction in the tomographic plane.
The image will be loaded automatically, left click and drag to draw an area as shown in the
example picture on the right panel (5 - Figure 11).
Both measures have to be in the range from 54.0mm to 66.0mm (nominal 60mm).
Report these values in the "Length measure" and "Width measure" cells of the QC log book at
paragraph 8.5.12.
8.5.8 Slice thickness
Click on "Next measure" button (6 - Figure 11) to proceed with the "Slice thickness" test, which
gives information about the geometry of the 3D reconstruction along the z axis.
The image will be loaded automatically, left click and drag to draw an area as shown in the
example picture on the right panel (5 - Figure 11).
Verify that the Slice thickness value displayed is in the range from 15.3mm to 18.7mm (nominal
17.0mm).
Report these values in the "Slice thickness" cell of the QC log book at paragraph 8.5.12.