Hello
All the artefact are circular.
You must investigate around the detector.
Can also possible that you have no fault but the ct need of calibration only.
Let me know.
Regards
Umberto
Dear Dr. Dashuren, it would be helpful to know the answers to a few of the following questions regarding your ring artifacts.
1. Does the ring artifact show up on all slice thicknesses?
2. Is this ring artifact reproducible? Does it occur every time you scan?
3. Is the ring artifact very pronounced (easy to see and usually bright) or more subtle and more difficult to see?
4. Do you see this ring artifact on all Fields of View? (FOV) if not please indicate which FOV you see this artifact on. SS FOV only, SS & S FOV only, M-S & SS only, L- M- S & SS only, or all FOV's LL-L-M-S-SS.
5. If the ring artifact is pronounced (easy to see and bright) it is likely that there is a defective printed wiring board (PWB) in the DAS (Data Acquisition System). There are two types of boards that can cause a ring artifact. There are 38 QV PWB's and 19 ADC2 PWB's in the DAS. Any one of these can cause a ring artifact.
6. To identify which board is causing the problem requires some work. The first step is to do the following. Click on Utility, Setup Utility, and then Info Mask, Find the selection for Recon Rows and enable it. (the button should turn yellow).
Scan an image that shows the ring artifact and select the slice that show the ring artifact the best. You will now see a string of 16 characters displayed in the upper left of image. This information is written in hex and needs to be decoded to decimal numbers for the information to be useful. If you could take a picture of this image showing the ring artifact and the recon row enabled I can help you go further to identify the defective part. If the ring artifact is more subtle and harder to see then perhaps NRA calibration will resolve the issue.
This technical support is provided by IMES (International Medical Equipment Services) and I can be reached via email at rrogers@rell.com. IMES has a full selection of parts if you need to place an order for parts to resolve your ring artifact issue.
This artifact occur only first patient scan in the every moring specially head scan. Artifact shows patient's head images but Not in all slice. It shows latest slices of head scan, that means in thin scan. The ring Artifact shows pronounced this case. Not shows in abdominal scan etc.
Dear Dr. Dashuren, yes it is very possible that room temperature can cause detector instability. The environmental conditions specified for the scan room are as follows. 18C-28C where median value is 20C-26C. Fluctuation around the median not to exceed + or - 2C. The relative humidity should also be in the range of 40%-80% (No Condensation). Is heat maintained in the scan room 24 hours every day? My understanding is that if you are located in Ulaanbaatar then the temperature in the early hours before sunrise can drop to -35--40C. That is very cold and if the scan room temperature is not maintained at the above mentioned median values it would be a likely cause of ring artifacts. Especially if as the scan room warms up later in the day and you do not see the ring artifact on the thin slice on head scan. A couple more notes. When you shut the scanner down at night are you turning off the switch at console (White switch) or turning off the circuit breaker on the wall that sends power to entire system? The circuit breaker on the wall should not be turned off as this allows power to the heating unit for detector temperature stabilization. One more note. I believe that the altitude of Ulaanbaatar is approximately 1350 metres above mean sea level. Special considerations have to be taken when this scanner is installed at elevations higher then 1000 metres above sea level.
If your artifact does not show up on head scan thin slices later in the day it would be a very good assumption that room temperature is the cause. It would be a good idea to perform NRA water and air calibration for the Small (S FOV)240 mm FOV but only after room temperature is completely stabilized within specifications.
This technical support is courtesy of IMES (International Medical Equipment Services)
I have ring artifacts on my Aquilion 4. Those artifacts are very pronounced and occur on 2nd and 3rd rows of each scan for almost all thickbess - 8mm; 5mm; 4mm; 3mm and 2mm.
According the manual it could be due to bus problem in DAS MDDC PWB. I have tried to use DCA programme to allocate the wrong PWB but no success. May I ask you for your e-mail for more detail information?
Thanks,
Robert Nurbekyan
ULTRAIMAGING LLC
Yerevan, Armenia
MTC
Aquilion 64 Image problem
November 30, 2015 12:25
Hello friends Someone could you help me please.I am from Mongolia we have Toshiba Aquilion64. Recently the some circle is shows scanned images ...
Please advice us.
Dr.Dashsuren
skype: dashka02
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umberto sciunnach
re: Aquilion 64 Image problem
November 30, 2015 05:26
Hello
All the artefact are circular.
You must investigate around the detector.
Can also possible that you have no fault but the ct need of calibration only.
Let me know.
Regards
Umberto
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MTC
re: re: Aquilion 64 Image problem
December 01, 2015 07:47
Dear Umberto,
Thank you very much for your reply.
Could you teach us how to do calibration ?
What is your contact info ?
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umberto sciunnach
re: re: re: Aquilion 64 Image problem
December 02, 2015 07:21
Hello
My mail
umbertosc1957@gmail.com
Regards
Umberto
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MTC
re: re: re: re: Aquilion 64 Image problem
December 02, 2015 09:43
Hello, I have sent email yesterday with some artifact images. Could you help us to solve artifact ? Do i need some calibration ? Please teach me ?
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Rick Rogers
re: Aquilion 64 Image problem
December 02, 2015 11:39
Dear Dr. Dashuren, it would be helpful to know the answers to a few of the following questions regarding your ring artifacts.
1. Does the ring artifact show up on all slice thicknesses?
2. Is this ring artifact reproducible? Does it occur every time you scan?
3. Is the ring artifact very pronounced (easy to see and usually bright) or more subtle and more difficult to see?
4. Do you see this ring artifact on all Fields of View? (FOV) if not please indicate which FOV you see this artifact on. SS FOV only, SS & S FOV only, M-S & SS only, L- M- S & SS only, or all FOV's LL-L-M-S-SS.
5. If the ring artifact is pronounced (easy to see and bright) it is likely that there is a defective printed wiring board (PWB) in the DAS (Data Acquisition System). There are two types of boards that can cause a ring artifact. There are 38 QV PWB's and 19 ADC2 PWB's in the DAS. Any one of these can cause a ring artifact.
6. To identify which board is causing the problem requires some work. The first step is to do the following. Click on Utility, Setup Utility, and then Info Mask, Find the selection for Recon Rows and enable it. (the button should turn yellow).
Scan an image that shows the ring artifact and select the slice that show the ring artifact the best. You will now see a string of 16 characters displayed in the upper left of image. This information is written in hex and needs to be decoded to decimal numbers for the information to be useful. If you could take a picture of this image showing the ring artifact and the recon row enabled I can help you go further to identify the defective part. If the ring artifact is more subtle and harder to see then perhaps NRA calibration will resolve the issue.
This technical support is provided by IMES (International Medical Equipment Services) and I can be reached via email at rrogers@rell.com. IMES has a full selection of parts if you need to place an order for parts to resolve your ring artifact issue.
Regards,
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MTC
re: re: Aquilion 64 Image problem
December 03, 2015 01:09
Dear Sir,
This artifact occur only first patient scan in the every moring specially head scan. Artifact shows patient's head images but Not in all slice. It shows latest slices of head scan, that means in thin scan. The ring Artifact shows pronounced this case. Not shows in abdominal scan etc.
Is it possible depends from Room Temperature ?
Thank you for your support.
to rate and post a comment
Rick Rogers
re: re: re: Aquilion 64 Image problem
December 03, 2015 01:53
Dear Dr. Dashuren, yes it is very possible that room temperature can cause detector instability. The environmental conditions specified for the scan room are as follows. 18C-28C where median value is 20C-26C. Fluctuation around the median not to exceed + or - 2C. The relative humidity should also be in the range of 40%-80% (No Condensation). Is heat maintained in the scan room 24 hours every day? My understanding is that if you are located in Ulaanbaatar then the temperature in the early hours before sunrise can drop to -35--40C. That is very cold and if the scan room temperature is not maintained at the above mentioned median values it would be a likely cause of ring artifacts. Especially if as the scan room warms up later in the day and you do not see the ring artifact on the thin slice on head scan. A couple more notes. When you shut the scanner down at night are you turning off the switch at console (White switch) or turning off the circuit breaker on the wall that sends power to entire system? The circuit breaker on the wall should not be turned off as this allows power to the heating unit for detector temperature stabilization. One more note. I believe that the altitude of Ulaanbaatar is approximately 1350 metres above mean sea level. Special considerations have to be taken when this scanner is installed at elevations higher then 1000 metres above sea level.
If your artifact does not show up on head scan thin slices later in the day it would be a very good assumption that room temperature is the cause. It would be a good idea to perform NRA water and air calibration for the Small (S FOV)240 mm FOV but only after room temperature is completely stabilized within specifications.
This technical support is courtesy of IMES (International Medical Equipment Services)
Regards
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MTC
re: re: re: re: Aquilion 64 Image problem
December 04, 2015 09:03
Thank you for your time and reply. I will check it and back to you again.
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umberto sciunnach
re: re: re: Aquilion 64 Image problem
December 03, 2015 01:53
Check recondtructor for bad contacts
Umberto
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MTC
re: re: re: re: Aquilion 64 Image problem
December 04, 2015 09:03
Ok, i will check contact also
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Robert Nurbekyan
re: re: Aquilion 64 Image problem
August 22, 2016 10:13
Hello Rick,
I have ring artifacts on my Aquilion 4. Those artifacts are very pronounced and occur on 2nd and 3rd rows of each scan for almost all thickbess - 8mm; 5mm; 4mm; 3mm and 2mm.
According the manual it could be due to bus problem in DAS MDDC PWB. I have tried to use DCA programme to allocate the wrong PWB but no success. May I ask you for your e-mail for more detail information?
Thanks,
Robert Nurbekyan
ULTRAIMAGING LLC
Yerevan, Armenia
to rate and post a comment