[Rtk-users] The Reconstruction Result has blur-image its possible due to motion blur effect or not? how can reduce it or correct it ?

[何明哲]

hi Simon thanks for your reply, but I still have some question ,

1) This is for non-rigid motion. If the motion is rigid, it can be
compensated by adjusting the source and detector positions and orientation
wrt to the object in the geometry file.
--> So this example is not suitable for dental CBCT? Or the motion blur of
dental CBCT can be ignored in the RTK algorithm because the motion is
rigid?

2) Again, detector parallel to isocenter is meaning less, the isocenter is
a point. And the goal of the geometry description is no to "make them
parallel" but to account for the actual geometry of the system wrt scanned
object.
--> If I need to ad adjust the Slant Case (the pic below is )，What methods
or parameters can I use to adjust it?
[image: image200.png]

(Pic form Wang, Zhao, et al. "Improvements in micro-CT method for
characterizing x-ray monocapillary optics." *Optics Communications* 504
(2022): 127474)

3) If I want to try to use dental CBCT or chest cavity CBCT to implement
and study the MCCBCTReconsttruction example
<https://wiki.openrtk.org/index.php/RTK/Examples/MCCBCTReconstruction#Deformation_vector_field>,
how can I collect or generate deformat.mha and motion signal.txt ?

Thanks for reply again.

BR,


Simon Rit <simon.rit at creatis.insa-lyon.fr> 於 2023年2月13日 週一 下午5:40寫道：

> 1) This is for non-rigid motion. If the motion is rigid, it can be
> compensated by adjusting the source and detector positions and orientation
> wrt to the object in the geometry file.
> 2) Again, detector parallel to isocenter is meaning less, the isocenter is
> a point. And the goal of the geometry description is no to "make them
> parallel" but to account for the actual geometry of the system wrt scanned
> object.
>
> On Mon, Feb 13, 2023 at 9:44 AM 何明哲 <m10512067 at yuntech.org.tw> wrote:
>
>> Hi Simon
>> Thanks for reply，
>>
>> 1) I understand what you mean, I will be check out geometric parameter
>> again , but if there is a motion blur caused by the motion of the gantry,
>> is there any suggested way to correct it? I have reference to
>> RTK/Examples/MCCBCTReconstruction
>> <https://wiki.openrtk.org/index.php/RTK/Examples/MCCBCTReconstruction#Deformation_vector_field>,
>> but this is an example of the motion signal of the chest cavity, If it is
>> dental CBCT case, which file or format should the motion signal be in? Or
>> is there a document for reference?
>>
>> 2) Thanks for your reply, I understand, because the source is considered
>> as a point, so if the detector is not parallel to the ISO Center, I just
>> adjust the  out of plane angle to make them parallel, am I right?
>>
>> The picture below is
>>
>> [image: 圖片1.bmp]
>>
>> thanks for your reply,
>> BR,
>>
>>
>>
>> Simon Rit <simon.rit at creatis.insa-lyon.fr> 於 2023年2月13日 週一 下午2:32寫道：
>>
>>> Hi,
>>> 1) I don't think this is due to detector blur. It seems to be a
>>> geometric problem. But it is hard to adjust it manually, this is generally
>>> calibrated.
>>> 2) I'm not sure I understand what your mean by "parallel to the source"
>>> as the source is assumed to be a point. If you only change SID, SDD, the 2
>>> source and detector X/Y offsets, the Gantry Angle and the in plane angle,
>>> the detector is parallel to the rotation axis. The out of plane angle is
>>> the angle between the axis and the detector.
>>> Simon
>>>
>>> On Fri, Feb 10, 2023 at 12:02 PM 何明哲 <m10512067 at yuntech.org.tw> wrote:
>>>
>>>>
>>>> Hi All
>>>>
>>>> I have use the CudaFDKConeBeamReconstructionFilter  algorithm to
>>>> reconstruct a set of CBCT images,
>>>> 1. )but I found that each slices contains blurry image area , because I
>>>> was using a flat panel detector   , so I tried to adjust the source offset
>>>> , inofplaneangle and outofplaneangle , but the blurry image area  still at
>>>> there, could this be due to detector motion blur effect? Or is there a
>>>> suggested way to correct it?
>>>>
>>>> 2). From the reference http://www.openrtk.org/Doxygen/DocGeo3D.html I
>>>> can know that adjusting the source offset and inofplaneangle /
>>>> outofplaneangle can ensure that the detector remains parallel to the
>>>> source, But how can I make sure that the Z-axis of the ISO, the detector
>>>> and the source are also kept parallel at the same time, Can I achieve this
>>>> by adjusting any parameters or using any method?
>>>>
>>>> The picture below is my result  for Question 1.
>>>> [image: 圖片1.png]
>>>>
>>>> thanks for your reply,
>>>> BR,
>>>>
>>>> 回覆轉寄
>>>> _______________________________________________
>>>> Rtk-users mailing list
>>>> rtk-users at openrtk.org
>>>> https://www.creatis.insa-lyon.fr/mailman/listinfo/rtk-users
>>>>
>>>
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