Wondering if anyone has seen this before and might be able to shed some light on this:
Replaced Tube, performed all alignments and a full detailed calibration. During the Auto CT Number adjustment, images shot on the Water phantom against the Large cals display several bands one dark then several lighter ones. No real pattern to the bands (not 16 channels apart, etc). Large Phantom against Large cals look good, small phantom against small cals look good, medium phantom against large cals show banding as well. Das checks out ok (with limited diagnostics available). Cannot really see anything in the scan data using the Image Analysis program.
I am going to replace the tube again but doubt this will fix. Any ideas would be greatly appreciated.
im only familiar with hsa and hla scanners but this sounds like a bad detector. Ive had to replace one years ago. also check collimator fuction and look in your err logs for coll. faults. Their is a mux card to that can cause issues. But that being said ive been shipped more than 1 bad tube before... haha. good luck with it.
How many bands do you have? It sounds like beam hardening artifact. The tube may, in fact, be causing the troubles. If that does not work, look closely at the POR and filter alignments.
Elliot Marcus
LightSpeed Ultra Problem
December 20, 2008 11:46
Wondering if anyone has seen this before and might be able to shed some light on this:
Replaced Tube, performed all alignments and a full detailed calibration. During the Auto CT Number adjustment, images shot on the Water phantom against the Large cals display several bands one dark then several lighter ones. No real pattern to the bands (not 16 channels apart, etc). Large Phantom against Large cals look good, small phantom against small cals look good, medium phantom against large cals show banding as well. Das checks out ok (with limited diagnostics available). Cannot really see anything in the scan data using the Image Analysis program.
I am going to replace the tube again but doubt this will fix. Any ideas would be greatly appreciated.
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Josh Nance
Re: LightSpeed Ultra Problem
December 20, 2008 10:14
im only familiar with hsa and hla scanners but this sounds like a bad detector. Ive had to replace one years ago. also check collimator fuction and look in your err logs for coll. faults. Their is a mux card to that can cause issues. But that being said ive been shipped more than 1 bad tube before... haha. good luck with it.
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Ralph Childs
Re: LightSpeed Ultra Problem
December 21, 2008 12:51
Elliot,
How many bands do you have? It sounds like beam hardening artifact. The tube may, in fact, be causing the troubles. If that does not work, look closely at the POR and filter alignments.
Scooter
scanner1@eim.ae
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