In a recently installed HiSpeed CTi, iam getting intermittent ring artifacts. It is more prominent in the brain posterior fossa. The detector slope test fails with 112 code.
Also while doing qcal, the hot cal procedure shows error in scans 17-21 and 37-40.
The pop noise test also fails.
I had done a LFC on this system, since the hard disk had failed during installation.
Is there a calibration procedure mistake that iam doing, since i did the image calibration from scratch?
Elliot is correct. The main items are the Plane of Rotation and Beam on Window. If these are okay, you better check the collimator filter for small cracks. Also, there could always be contrast on the mylar and/or detector. Lastly check the detector power supply and pressure if it is a xenon system.
Yes the DAS power supply, actually ther are three of them sitting side by side. The problem I had as best I can recall was the one on the left side (5 Volt) had a 2 volt saw tooth ripple coming out of it.
I wouldn't be too worried about the failing Pop and Noise test... most scanners fail that test with no noticeable image quality issues, but definitely check out your DAS power supplies for ripple. With that said, first and foremost check your tube alignments, particularly POR. A misaligned POR can and will cause qcal failures. Once all alignments, POR, BOW, ISO, and CBF are verified good and your DAS power supplies are good, I would perform a full cal starting with qcal.
I completed the POR. BOW and Iso center alignment. The POR was definately little out of position. Also i adjusted the DAS power supplies. Still the hot Q cal fails in some 10 slices. Also it does not do CBF alignment.After the air scan and before the bow tie scan in the CBF filter alignment procedure, the SBC gives an error " Record key not defined in DB" ,
I did a test scan without completing the CBF alignment. It did went through with good images but im not sure whether the problem is rectified.
OK... Did the system pass Q-Cals before you installed it? You could be troubleshooting someone elses problem if you did not fully inspect and calibrate the machine before it was relocated.
I agree with Ralph... check the collimator filter for cracks. Since this is a CT/i you have a solid state detector so there's not worry about gas pressure inside the detector. If power supplies, alignments, and collimator filter all are ok... you might be looking at a bad detector. I am concerned about the error you are getting when trying to do CBF scans. What disk drive did you replace... was it in the OC or SBC?
The current status is that the frequency of artifact have reduced.It comes in 1 or 2 slices. The POR and BOW adjustment did make a difference. Also sometimes the artifact does not come as a complete circle. It comes as half or quarter hemisphere.
Is it some kind of noise that the DAS is picking up?
Also the SBC hard disk was not replaced, it was only reconfigured. Could this cause the CBF alignment to fail?
With the old collimators that use the Polyethelyne filters, a partially open ring artifact was a definite sign of a cracked collimator filter. If your collimator has a Poly filter, you might need to remove it from the collimator to see the crack... Have you noticed if the artifact is heat related? hairline cracks in the filter get exaggerated with heat
Pease let us know wt it means scratch, as before any calibration Air calibration can help, if not then You should try software based calibration, even if that fails, then try to locate channels which shows variation to the normal. Uselly Posterior if affected then see retical count i.,e related to penitration on the object
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jas kumar
HiSpeed CTi problem
August 07, 2007 04:35
In a recently installed HiSpeed CTi, iam getting intermittent ring artifacts. It is more prominent in the brain posterior fossa. The detector slope test fails with 112 code.
Also while doing qcal, the hot cal procedure shows error in scans 17-21 and 37-40.
The pop noise test also fails.
I had done a LFC on this system, since the hard disk had failed during installation.
Is there a calibration procedure mistake that iam doing, since i did the image calibration from scratch?
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Bill Rice
Re: HiSpeed CTi problem
August 08, 2007 01:52
Check your power supplies for high ripple, I had the same problem about a year ago.
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jas kumar
Re: HiSpeed CTi problem
August 09, 2007 05:32
Thanks Bill. I will check on that.When u say power supply, you mean the DAS supply right?
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Ralph Childs
Re: HiSpeed CTi problem
August 12, 2007 12:29
Jas,
Elliot is correct. The main items are the Plane of Rotation and Beam on Window. If these are okay, you better check the collimator filter for small cracks. Also, there could always be contrast on the mylar and/or detector. Lastly check the detector power supply and pressure if it is a xenon system.
Scooter
scanner1@eim.ae
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Bill Rice
Re: HiSpeed CTi problem
August 13, 2007 11:47
Yes the DAS power supply, actually ther are three of them sitting side by side. The problem I had as best I can recall was the one on the left side (5 Volt) had a 2 volt saw tooth ripple coming out of it.
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Elliot Marcus
Re: HiSpeed CTi problem
August 09, 2007 03:31
Jas,
I wouldn't be too worried about the failing Pop and Noise test... most scanners fail that test with no noticeable image quality issues, but definitely check out your DAS power supplies for ripple. With that said, first and foremost check your tube alignments, particularly POR. A misaligned POR can and will cause qcal failures. Once all alignments, POR, BOW, ISO, and CBF are verified good and your DAS power supplies are good, I would perform a full cal starting with qcal.
Regards,
Elliot
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Rajesh Nair
Re: HiSpeed CTi problem
August 10, 2007 02:08
Thanks everyone for the invaluabe information. I will be working this weekend on this system. Will keep you guys updated.
Regards,
Jas
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farhan zeb
Re: HiSpeed CTi problem
September 17, 2011 07:10
INDIGO2 4.4 version
1_) dear friend i have loaded the software first i loaded the OS then
Applications and after that i have to configure or load the SBC with OC when i type the command loadSBC so the
following error occurs Not enough free spcae can not load network software
when i try to connect to SBC i type the command cu sbc but following error occured connect failed: cant't access
device
i have tried all the procedure from LFC but still same problem i have tried to bring it to the MC6080> prompt but
still nothing happened still same problem
but when i use the command rsh sbc and reconfig the sbc and after st so during initialization system goes shut down
itself .
NOTE:
when i have loaded the application software so after that when i open the unix shell so an message
appeared executing install.dasm no dasm's found
so please help me i'll wait for your reply
2_) Dear friend i have lost the system state also of cti indigo2 system and and the oc disk drive have been crashed
i have
replace the disk drive and loaded the software from cold so i have lost my system state so now i have loaded the
software but i have no system state but there is need of the system state so what should i do now there is the
method to restore files in the LFC but how should i access the unix shell with crash disk drive so please tell me
what will be the alternative way to skip this step and start the applications.
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jas kumar
Re: HiSpeed CTi problem
August 13, 2007 07:57
I completed the POR. BOW and Iso center alignment. The POR was definately little out of position. Also i adjusted the DAS power supplies. Still the hot Q cal fails in some 10 slices. Also it does not do CBF alignment.After the air scan and before the bow tie scan in the CBF filter alignment procedure, the SBC gives an error " Record key not defined in DB" ,
I did a test scan without completing the CBF alignment. It did went through with good images but im not sure whether the problem is rectified.
Thanks.
Regards,
Jas
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Elliot Marcus
Re: HiSpeed CTi problem
August 13, 2007 05:03
OK... Did the system pass Q-Cals before you installed it? You could be troubleshooting someone elses problem if you did not fully inspect and calibrate the machine before it was relocated.
I agree with Ralph... check the collimator filter for cracks. Since this is a CT/i you have a solid state detector so there's not worry about gas pressure inside the detector. If power supplies, alignments, and collimator filter all are ok... you might be looking at a bad detector. I am concerned about the error you are getting when trying to do CBF scans. What disk drive did you replace... was it in the OC or SBC?
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jas kumar
Re: HiSpeed CTi problem
August 20, 2007 10:10
The current status is that the frequency of artifact have reduced.It comes in 1 or 2 slices. The POR and BOW adjustment did make a difference. Also sometimes the artifact does not come as a complete circle. It comes as half or quarter hemisphere.
Is it some kind of noise that the DAS is picking up?
Also the SBC hard disk was not replaced, it was only reconfigured. Could this cause the CBF alignment to fail?
to rate and post a comment
Elliot Marcus
Re: HiSpeed CTi problem
August 20, 2007 02:12
With the old collimators that use the Polyethelyne filters, a partially open ring artifact was a definite sign of a cracked collimator filter. If your collimator has a Poly filter, you might need to remove it from the collimator to see the crack... Have you noticed if the artifact is heat related? hairline cracks in the filter get exaggerated with heat
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sanjay Guptta
Re: HiSpeed CTi problem
August 10, 2007 04:07
Pease let us know wt it means scratch, as before any calibration Air calibration can help, if not then You should try software based calibration, even if that fails, then try to locate channels which shows variation to the normal. Uselly Posterior if affected then see retical count i.,e related to penitration on the object
to rate and post a comment