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View Full Version : Re: How to scan x-rays revisited...



Tahir H. Chaudhry
07-21-2000, 01:32 AM
This is an excellent repines, and we have found it works well for us too.

Thank you.

Sincerely,
Tahir
www.neuronet.com

> Hello All:
>
> Thank you for all of the many responses to my query regarding scanning
> x-rays. This email summarized the responses for those who were interested
> in knowing the outcome of this quandry.
>
> In review, I wanted to scan x-rays of small animals (mice or rats) and
> analyze them for morphology and bone density. Standard, commercially
> available scanners do not have the power to scan x-rays and maintain
> resolution and coloring. I tried to place several different lightsources
> over the scanner with little luck - the lightsource would change over time
> (i.e. the scanner could detect temperature changes in the light over time -
> which would make the bony portion of the x-rays appear brighter over time).
> I wanted to analyze these x-rays for bone density (via the color intensity
> of the bony areas) and for shape (i.e. cortical thickness). The changes in
> the light source over time - as well as the uneven distribution of light
> over the surface of the x-ray (resulting in lighter and darker regions) made
> this solution unacceptable for use in small animals (although it may work
> for larger animals and humans).
>
>
>
> Here is a summary of the responses and my comments on each:
>
> 1) Try having a mirror cut to match the dimensions of your scanner. Place
> the
> x-ray on the scanner and then place the mirror over it. The quality isn't
> absolute top notch, but it ain't bad and is certainly cheaper than buying a
> scanner dedicated for x-rays! This isn't difficult, any glass shop can do
> it no problem and inexpensively.
>
> *** We tried using a large mirror with several different HP scanners (HP
> IIC, HP 5C, and an HP 5300C). This did not work well. In fact, several
> responders told me that films are best scanned using transmitted light,
> rather than reflected light.
>
>
>
> 2) Use the x-ray as a photo negative and print a contact print -
> ie place the x-ray on some 10x8 photo paper, expose it to
> white light, and develop the print as you would any photo. This print can
> then be scanned in by a conventional scanner.
>
> *** We tried this through our Universities publishing department - it
> resulted in a high degree of variability on the contact prints when
> processing the same x-ray more than once. Also, it does not pick up areas
> where bone is scarce (that can be seen on the x-ray) such as the ulna,
> radius, and hand bones of a mouse.
>
>
>
> 3) Take pictures with a high quality digital camera when they are on a
> light board, etc.
>
> *** A light board provides an uneven lightsource. If using the images for
> the purpose of publishing an x-ray, this works fine. If you want to analyze
> for intensity, this is not acceptable, in my opinion, as - once again - the
> gradations in the light source cause some areas of the image to appear
> artifically lighter.
>
>
>
> 4) Lay a lightbox on top of the x-ray on the scanner.
>
> *** Same as #3. Also, light boxes with flourescent lamps can form
> diffraction patterns on the scanned image.
>
>
>
> 5) One lab bought a $60 000 x-ray scanner that does the
> job - results are at: http://www.health.latrobe.edu.au/Schools/POD/home.htm
>
> *** These are expensive medical image scanners that will probably do a much
> better job than commercially available scanners + transparency adapters. If
> you need very high resolution and can afford it, this may be a good
> solution. There are many schools that have such equipment in radiology
> departments.
>
>
>
> 6) Most people who responded to my query suggested using a transparency
> adapter. This is a special cover that works with your scanner to provide a
> transmitted light source that tracks the scanning bar. Companies (and
> scanners) recommended by responders were:
>
> Hewlett Packard at
> http://www.shopping.hp.com/cgi-bin/shopping/hpdirect/shopping/scripts/home/a
> pi_login.jsp?product_code=C7671A
> UMAX Astra 1220S scanner with ATA-3 transparency adaptor (www.umax.com) (up
> to 8"x10").
> UMAX Powerlook III Flatbed scanner.
> Umax Mirage IIse professional (up to 12"x17")
> Lumiscan 150 the x-ray film scanner
>
> *** It turns out that I was able to obtain a scanner and transparency
> adapter for free to test these suggestions. It is an HP Scanjet 5300C with
> a transparency adapter. Thus far, it is working very well - excepting the
> small area that the transparency adapter covers (5"x5"). The scanned images
> appear to be consistently "lit" - resulting in no lighter/darker spots on
> the image. And I can "normalize" all of my images by using a phantom - I
> made an epoxy disk containing small sections of cortical bone with
> thicknesses of 0.25, 0.5,...mm which I scan in on every image and use to set
> a standard intensity when I analyze my images in Photoshop. Thus far, this
> seems to be the most cost effective result that yields good results.
>
> If you do not have the resources to buy such a system (much less than
> $1000), then you can pay a professional service to do this for you and some
> universities have publishing departments that do this as well.
>
>
> Good luck and happy scanning,
>
> Virginia Ferguson, M.S.
>
> Orthopaedics Research Group
> BioServe Space Technologies
> Campus Box 429
> University of Colorado at Boulder
> Boulder, CO 80309
>
> Phone: 303.735.2494
> Fax: 303.492.8883
>
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