DigiTecNotesAsk Engineering>> Tip of the MonthEngineering Challenge of the Month

Tip of the Month

Review artifact evaluation images before performing image related service. It is helpful to know if artifacts were present before you start your work.

Past Tips of the Month

Remember to cover the detector with a lead apron when making non imaging test exposures.

Before beginning service, turn off auto image push. This will prevent an excess of service images from ending up on review station or PACS. Remember to turn it on again when service is complete.

Test the UPS capacity at the end of a PM or service visit. After the test, the system may be down while the UPS recharges.

Keep a fresh supply of CDs in your service kit. If it is late and the customer is gone, you may not be able to locate their supply.

Acquire and carefully inspect an artifact test image before and after performing work on the imaging chain. Having an image to compare with will be helpful when your work / adjustments are complete.

Keep current and previous data "backup" on site. Being able to restore to a past configuration may be helpful.

Never use a compression paddle or detector as a tool bench. Image artifacts or damage may result.

Take the time to backup data at every PM.. a current back up is valuable if the system fails.

When working with the c-arm inverted, tape a piece of cardboard over the collimator opening, it will keep you out of trouble.

Record radiation output at a predetermined manual technique. Data will be useful for future troubleshooting.

Turn off auto decompression before exposing a phantom in lateral position.

Rotate the c-arm before re-installing covers; dropped / lost harware will fall to the floor.

Do not used compressed air to blow dust from tube head, use a vacuum.

Compare the accuracy of your kV meter with your physicist’s. Knowing the difference will be helpful.

If an artifact is blurry, its source is probably above the film plane. If it appears sharp on film, it is most likely closer to the film plane.

Test the operation of the cassette presence sensor with the c-arm inverted. If it operates there, it will operate in all positions.

C-arm won’t move ? Check if the system “thinks” there is compression force applied.

At each PM, remember to inspect the wiring to the collimator lamp. The bulb can draw a surprising amount of current.

Download the FDA guidance document and keep it on your laptop. Having it on hand can be a big help and time saver.

Record the radiation output of the system at a specific manual technique. The data will be helpful in the future.

When calibrating a phototimer remember that BR12 and Acrylic are not the same… use what your physicist uses.

When trying to identify the source of image artifacts, run a phantom image through the processor at a 45 degree angle. Place the image on the viewbox and step back a few feet.Artifacts or roller marks streaking across the film will be more visible.

Screen related artifacts can be eliminated by double loading the cassette. The film in direct contact with the screen will block the light and allow the second film to be imaged from x-ray only. The technique will have to be increased but this will eliminate screen related artifacts when testing.

Measure the line voltage at each PM. Having a record of the voltage with and without load will be helpful if ever power related problems are suspected.

When trying to locate the source of image artifacts, use magnification mode. Tube port and filter artifacts “invisible” to large focal spot and a bucky, will be more easily seen in magnification mode.

Record the site setup data of the film flasher and operator console. It will be useful if one of the CPU batteries dies.

When adjusting phototiming, use one cassette. The variation between cassettes may lead to inaccurate measurements and needlessly extend your calibration time.

Take the time to record line voltage, load and no load, at each PM.