Things you should know about digital radiography

RE: Things you should know about digital radiography

Silvia Maldonado — Wed, 29 Jul 2015 21:06:23 GMT

[quote user="Mike Martin"]

[quote user="Silvia Maldonado"]How can I find more of Mike's presentations[/quote]

Ah, this is the first one on-line. Keep an eye on our 'CPD' listings on our website for any up and coming talks.

Great! having a look at your website...ohhh... Kenilworth? I've been at the castle just few days ago! Awwww... envy you, so much history to gossip about in there!

[/quote]

RE: Things you should know about digital radiography

Mike Martin — Wed, 29 Jul 2015 11:36:50 GMT

[quote user="Silvia Maldonado"]How can I find more of Mike's presentations[/quote]

Ah, this is the first one on-line. Keep an eye on our 'CPD' listings on our website for any up and coming talks.

RE: Things you should know about digital radiography

Mike Martin — Wed, 29 Jul 2015 11:34:54 GMT

[quote user="Michael Woodhouse"]Would you increase the KVA and leave the time the same?[/quote]

Yes, we tend to increase the kV, keeping the Mas at 6 and so a fast (short) time exposure for moving chests. At an estimate the kV goes up by 20-30%, but you need to work this out using the 'how to create an exposure chart' guide for each machine and combo of cassettes etc. So you need an exposure chart for small things without a grid or bigger animals with a grid. If the image with a grid is poorer than without, then I'd probably not use a grid (as this might be a limitation in the power of your x-ray generator).

RE: Things you should know about digital radiography

Silvia Maldonado — Tue, 28 Jul 2015 01:13:44 GMT

Someone else with a possible silly question. I've downloaded that dropbox thing (so I admit I didn't know of that either) and now... How can I find more of Mike's presentations?

RE: Things you should know about digital radiography

Michael Woodhouse — Mon, 27 Jul 2015 18:21:07 GMT

Interesting re grids. The first practice where I worked we doubled the MAS when using a grid (usually to 20 for a big dog) and never been very happy with the film. Would you increase the KVA and leave the time the same?

How much higher would you expect (double, +25% etc)?

Thanks

RE: Things you should know about digital radiography

Mike Martin — Mon, 27 Jul 2015 18:13:32 GMT

Yes, the High Frequency (HF) units are generally good. I'm not sure of the formula to convert them from 'old' generator power. But an estimate of 150mA sounds correct to me. Good question, I'll ask someone.

RE: Things you should know about digital radiography

Andy Elliott — Sun, 26 Jul 2015 18:50:06 GMT

Thanks Mike,

I have a fairly new portable X-ray generator which I thought was adequately powerful. It was a HF 60mA which I understood was equivalent to an effective 150 mA i.e.. 2.5x. Is this correct?

Andy

RE: Things you should know about digital radiography

Braden Collins — Thu, 23 Jul 2015 00:57:41 GMT

The principles of good radiography are still the same, whether it's digital or film. A grid still needs to be used for thicker aminals to reduce scatter hitting the film/screen. It may not make much difference to us GP vets, but refer chest rads of a mastiff's chest to a radiologist to interpretand, and a grid will make a difference.

RE: Things you should know about digital radiography

Silvia Maldonado — Thu, 23 Jul 2015 00:40:23 GMT

Very clear, simple and concise. Quick to see, easy to understand.

RE: Things you should know about digital radiography

bob lehner — Wed, 22 Jul 2015 16:38:11 GMT

[quote user="Clive Ansell"]One of my regular practices, where one of the partners has his certificate in radiology, still uses traditional film and automatic processor, and his radiographs cannot be faulted.[/quote]

I agree - I've come across some rather rubbish digital systems in my time - but it's not a PSS requirement to have a digital system - just that if you do have a digital system then you should still use a grid - which was the original question I was answering (.....before being attacked by the anti-PSS jihadis).

RE: Things you should know about digital radiography

Clive Ansell — Wed, 22 Jul 2015 15:48:05 GMT

[quote user="bob lehner"]

[quote user="Evelyn Barbour-Hill"]What the hell has it got to do with practice standards?[/quote]

Errm ... I think it might have something to do with trying to ensure that practices are doing things well - i.e. getting a better quality X ray.

Odd I know - but do try thinking about it old chap.....you usually moan/rant about PSS just being a load of box ticking and nothing to do with clinical performance.

[/quote]

Although I much prefer to use it, I cannot see how digital radiograph necessarily raises practice standards. One of my regular practices, where one of the partners has his certificate in radiology, still uses traditional film and automatic processor, and his radiographs cannot be faulted.

RE: Things you should know about digital radiography

bob lehner — Wed, 22 Jul 2015 15:41:50 GMT

[quote user="Evelyn Barbour-Hill"]that's a bit daft, ducky.[/quote]

Thank you - I've been patronised by better folks than you....

(I think the general idea is that they should actually take it off the shelf and use it... yawn...).

RE: Things you should know about digital radiography

Evelyn Barbour-Hill — Wed, 22 Jul 2015 14:04:58 GMT

[quote user="bob lehner"]

[quote user="Evelyn Barbour-Hill"]What the hell has it got to do with practice standards?[/quote]

Errm ... I think it might have something to do with trying to ensure that practices are doing things well - i.e. getting a better quality X ray.

Odd I know - but do try thinking about it old chap.....you usually moan/rant about PSS just being a load of box ticking and nothing to do with clinical performance.

[/quote]

Sure.

To have a Practice Standard that the practice has radiography facilities adequate for obtaining diagnostic images of good quality, yes.

To have a Standard that they must keep a grid on the shelf, that's a bit daft, ducky.

[quote user="bob lehner"]....you usually moan/rant about PSS just being a load of box ticking and nothing to do with clinical performance.[/quote]

No I don't, I rant and moan about it for much more than that.

RE: Things you should know about digital radiography

bob lehner — Wed, 22 Jul 2015 13:29:42 GMT

[quote user="Evelyn Barbour-Hill"]What the hell has it got to do with practice standards?[/quote]

Errm ... I think it might have something to do with trying to ensure that practices are doing things well - i.e. getting a better quality X ray.

Odd I know - but do try thinking about it old chap.....you usually moan/rant about PSS just being a load of box ticking and nothing to do with clinical performance.

RE: Things you should know about digital radiography

Evelyn Barbour-Hill — Wed, 22 Jul 2015 12:48:27 GMT

[quote user="bob lehner"]

[quote user="Sarah Keir"]With the digital system, I have never had to use a grid to get good quality images. Am I doing something wrong?[/quote]

This question crops up quite often at PSS inspections.

The powers-that-be looked into it and took advice from eminent DVRs who advised that a grid should be used with digital systems - and this is now a specific requirement for PSS.

[/quote]

What the hell has it got to do with practice standards?

RE: Things you should know about digital radiography

bob lehner — Wed, 22 Jul 2015 12:32:04 GMT

[quote user="Sarah Keir"]With the digital system, I have never had to use a grid to get good quality images. Am I doing something wrong?[/quote]

This question crops up quite often at PSS inspections.

The powers-that-be looked into it and took advice from eminent DVRs who advised that a grid should be used with digital systems - and this is now a specific requirement for PSS.

RE: Things you should know about digital radiography

Mike Martin — Wed, 22 Jul 2015 11:48:35 GMT

[quote user="Sarah Keir"]With the digital system, I have never had to use a grid to get good quality images[/quote]

If your images are good without a grid, then that's great.

At the end of the day, the proof is in the pudding. :)

RE: Things you should know about digital radiography

Mike Martin — Wed, 22 Jul 2015 11:47:16 GMT

The general consensus would be that any animal that is big, eg. >12-15cm in depth, needs a grid. However a grid needs a more x-rays to compensate for the attenuation of the grid lines, that means a more powerful machine.

So if you have a 'good' powerful x-ray machine then yes (for bigger animals), but more so with obese ones than non-obese. If you have a 'poor' or 'very poor' powered machine, then maybe a grid will only add more problems than help. That would need trial and error; trying with and without.

The grid positioning is the same as for film x-ray; but some should be aligned to the x-ray bean direction (tube side) if it says so on the grid.

Hope this helps?

RE: Things you should know about digital radiography

Sarah Keir — Thu, 16 Jul 2015 13:59:39 GMT

With the digital system, I have never had to use a grid to get good quality images. Am I doing something wrong?

Sarah

RE: Things you should know about digital radiography

Rob Loxley — Wed, 15 Jul 2015 23:48:29 GMT

Some questions

- given the chest is mainly full of air (which does little scattering), when radiographing non-obese patient chests are grids necessary?

- if using a grid does it matter (in practice) which way the grid goes with respect to the way a CR casette is scanned?

RE: Things you should know about digital radiography

Mike Martin — Mon, 13 Jul 2015 12:09:53 GMT

[quote user="weltonvet"]Do you have a formula equating depth of tissue to kV required?[/quote]

Its nearly linear. So to work out a chart, take a chest x-rays of something small and something big to work out the exposure for them. Then fill in the blanks.

ie. If something small with a chest depth of 10cm = 55kV and something big with a depth of 30cm is 80kv, plot those on a chart and fill in the gaps.

Hope that makes sense.

RE: Things you should know about digital radiography

weltonvet — Wed, 08 Jul 2015 17:18:34 GMT

Do you have a formula equating depth of tissue to kV required?

Sean

RE: Things you should know about digital radiography

mariette asselbergs — Wed, 08 Jul 2015 15:45:00 GMT

Thanks very much Arlo, think I will try to use it from now on. Have 5 starred your answer....

Mariette

RE: Things you should know about digital radiography

Mike Martin — Wed, 08 Jul 2015 14:52:54 GMT

[quote user="K Burton"]I cannot select my own exposure settings. We input into the DR programme what body part and view we are taking so does the system preprocess this and adjust the exposure accordingly[/quote]

I believe with some good DR systems there is an automatic exposure setting based on pre-exposure tests, so you would not need an exposure chart. but I'm not overly familiar with these, we'd need input from a radiographer/radiologist/imager on this.

RE: Things you should know about digital radiography

Kathryn Burton — Wed, 08 Jul 2015 12:04:28 GMT

Thanks, this is really helpful. We have DR in my current job but I use it once in a blue moon so don't fully understand how it works! Wrt creating exposure charts, our generator seems to have four preset memory functions so I cannot select my own exposure settings. We input into the DR programme what body part and view we are taking so does the system preprocess this and adjust the exposure accordingly?! Sorry if this is a silly question.