LOOKING FOR SOMEONE WHO CAN DO A REPAIR ON OR MAKE THE CABLE FOR ME.HAVE A SIEMENS 1.O T BOBY ARRAY COIL AND THE TECHS BROKE IT AT THE UPPER CONNECTOR,ONE COAX COMPLETELY BROBEN. THESE A VERY FINE COAX CABLE WITH VERY SMALL BNC CONNECTOR. ANY INFO PLEASE AND THANK YOU VERNE
you can chech the body coil by means of a small home made Hartley oscilator by a FET transistor.
simply measre the out put envelop, in case that there is a resonant LC circuit in nearby, the envelop output would decrease rapidly.
if there is a resistance in LC circuit, then the decreased output would be more.
it would give you an index on body coil.
you have to have a frequency counter to set the oscilator frequency directly match with the magnet frequency. U can also find the magnet frequency by this method.
also it is posible to measure the phase angle and magnitude of RF in transmit path precisely by a one Ohm non inductive resistor and the same RF Oscilator and a 2 chanel osciloscope.
put the oscilator, resistor and RF coil in series. mesure voltage of the resistor by one chanel and coil voltage by the other one in scope.
the 1st one is curent and the 2nd is voltage.
try to set both in phase with the highiest magnitude.
Best
Bagher Mahdavi
clinical medical physicist
MRI engineer
Linac engineer
Hi, where do you reside? Is there a methodology to measure the MRI body coil or surface coil preamplifier's SNR out of circuit?
We are purchasing a Siemens Magnetom Avanto 1.5 Tesla system. Do you do consultant work on "site planning"? Please contact me at edward.yan@va.gov. Thanks.
your variant to measure for example proton resonance frequency will not work ok, because search diapason can be to broad and resonance can be too narrow. Stability of your oscillator should be better than 100ppm and so on. To satisfy all requirements, you will come to standard nmr teslameter or about it.
I HAVE DONE BUSINESSES WITH TWO MAJOR VENDORS. THEY WERE EXPENSIVE AND HAD PROBLEMS HONORING WARRANTIES. THEY DID NOT PROVIDE SERVICE REPORTS. IF YOU WANT TO TRY THEM, YOU NEED TO OBTAIN AN OFFICIAL PRICE QUOTE AND WARRANTY COMMITMENT IN WRITING. WWW.MEDRAD.COM, USA 800-633-7231, INTERNATIONAL fax 412-767-4128, Medrad Inc. One Medrad Drive, Indianola, PA 15051-0780 USA. WWW.4SONORA.COM, USA 888-476-6672, Sonora Medical Systems, Inc., 1751 South Fordham Street, Suite 100 Longmont, CO 80503.
Sell your scrap MRI magnets! Top prices, free shipping, and fast pickups. Don't let dust-collecting, idle assets go to waste. Contact: ryan.swiderski@cyclicmaterials.earth or call 437-826-1621
VERNE CHAPPELL
MRI COIL RPAIR
June 12, 2006 09:26
LOOKING FOR SOMEONE WHO CAN DO A REPAIR ON OR MAKE THE CABLE FOR ME.HAVE A SIEMENS 1.O T BOBY ARRAY COIL AND THE TECHS BROKE IT AT THE UPPER CONNECTOR,ONE COAX COMPLETELY BROBEN. THESE A VERY FINE COAX CABLE WITH VERY SMALL BNC CONNECTOR. ANY INFO PLEASE AND THANK YOU VERNE
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Marshall Shannon
Re: MRI COIL RPAIR
June 12, 2006 11:20
We do cable repair in house on these units.
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Bagher Mahdavi
Re: MRI COIL RPAIR
June 13, 2006 01:19
Hi Forum
you can chech the body coil by means of a small home made Hartley oscilator by a FET transistor.
simply measre the out put envelop, in case that there is a resonant LC circuit in nearby, the envelop output would decrease rapidly.
if there is a resistance in LC circuit, then the decreased output would be more.
it would give you an index on body coil.
you have to have a frequency counter to set the oscilator frequency directly match with the magnet frequency. U can also find the magnet frequency by this method.
also it is posible to measure the phase angle and magnitude of RF in transmit path precisely by a one Ohm non inductive resistor and the same RF Oscilator and a 2 chanel osciloscope.
put the oscilator, resistor and RF coil in series. mesure voltage of the resistor by one chanel and coil voltage by the other one in scope.
the 1st one is curent and the 2nd is voltage.
try to set both in phase with the highiest magnitude.
Best
Bagher Mahdavi
clinical medical physicist
MRI engineer
Linac engineer
to rate and post a comment
Edward Yan
Re: MRI COIL RPAIR
June 13, 2006 11:03
Bagher,
Hi, where do you reside? Is there a methodology to measure the MRI body coil or surface coil preamplifier's SNR out of circuit?
We are purchasing a Siemens Magnetom Avanto 1.5 Tesla system. Do you do consultant work on "site planning"? Please contact me at edward.yan@va.gov. Thanks.
Edward Yan, B.S.E.E.
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Iosif Sogolov
Re: MRI COIL RPAIR
June 14, 2006 04:14
Hi Bagher,
your variant to measure for example proton resonance frequency will not work ok, because search diapason can be to broad and resonance can be too narrow. Stability of your oscillator should be better than 100ppm and so on. To satisfy all requirements, you will come to standard nmr teslameter or about it.
Iosif
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Edward Yan
Re: MRI COIL RPAIR
June 13, 2006 08:20
VERNE,
I HAVE DONE BUSINESSES WITH TWO MAJOR VENDORS. THEY WERE EXPENSIVE AND HAD PROBLEMS HONORING WARRANTIES. THEY DID NOT PROVIDE SERVICE REPORTS. IF YOU WANT TO TRY THEM, YOU NEED TO OBTAIN AN OFFICIAL PRICE QUOTE AND WARRANTY COMMITMENT IN WRITING. WWW.MEDRAD.COM, USA 800-633-7231, INTERNATIONAL fax 412-767-4128, Medrad Inc. One Medrad Drive, Indianola, PA 15051-0780 USA. WWW.4SONORA.COM, USA 888-476-6672, Sonora Medical Systems, Inc., 1751 South Fordham Street, Suite 100 Longmont, CO 80503.
EDWARD YAN, B.S.E.E.
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Gary Casey
Re: MRI COIL RPAIR
June 13, 2006 09:15
Contact Carolina Medical Parts for your coil repair. They are very good.
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Dan McGuan
Re: MRI COIL RPAIR
June 20, 2006 08:18
Verne,
Carolina Medical Parts is very good. They WILL honor their warranties and provide professional repair results.
The contact is...
http://www.cmparts.com/
877-287-2784
Good Luck,
Dan
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