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Dr Dale Miles - learndigital.net
Dr. Dale Miles


 
 

Much Ado about Scanners

Dale A. Miles DDS, MS, FRCD
Diplomate, ABOMR

Introduction

A lot of you have written me with questions about scanners for "digitizing" your radiographs. What is the best scanner? How much do they cost? Will it work with my software? These are the types of questions dentists are raising. The biggest question you need to first answer is "Why do I need to scan my films"?

In the first article published on this site (August, 2000) I wrote:

Indirect Image Acquisition

The indirect method of image acquisition converts original analog images (dental x-rays or radiographs) to digital images usually by a scanning process using digitization. This is also done with a CCD device, but it is a linear detector just like your fax machine, not a rectangular dectector like the intraoral CCD. Once digitized the resultant image can be further processed like any other digital image. For this type of "digital" image a commercial scanner, capable of scanning 600 dpi, with a transparency adapter in the lid is required. Color slides may also be scanned in this fashion.

Most of the image processing software offered in patient management packages, and those programs sold or bundled with digital x-ray systems, have the ability to import an image directly from a scanner. And, if you buy a scanner, they all come preloaded with image processing programs like Adobe PhotoshopTM so that you can "process" your image. The hardware and the software exists and is very "user friendly". But still, you need to ask yourself, "Why do I need to scan my films?"

Reasons to Scan

Not much has changed, except that scanner prices have come down in price. But why do you want to use this type of indirect digital imaging anyway? There may be several reasons, including:

    1. Archiving your current film repository

    2. Recovering older, less diagnostic film information from stored films
    3. Sending a film image to the insurance carrier
    4. Building case material for presentation
    5. Scanning 35 mm slides, so why not do x-rays too
    6. Because you just want to

The most "legitimate" reasons are #s 1-4. Scanning your entire file cabinet collection is noble, but is EXTREMELY TIME CONSUMING and EXTREMELY COSTLY. In may this year a colleague of ours, at a recent meeting at which I spoke, told the group he had just scanned and stored his entire repository of x-rays from his patient charts. It took a high school student 8 months, working 3-4 hours/day to scan the collection. It cost the dentist $20,000! But, after "going digital" in his office, he’s now finally "totally digital" because of the scanning procedure.

The Skinny on Scanners

Table 1 outlines the commercially available scanners capable of handling your film size needs if you plan to scan the typical intraoral, panoramic and cephalometric sized x-ray films.

Table 1

Maker/Model
Bit Depth
Optical
Resolution
Max. Size
Image
Software
Cost
(MRSP)
Microtek ScanMaker 9600XLDP
36
600x12000
12x17"
Photoshop LE
1499.99
* the ScanMaker 8700 is only $999, but can only scan 8" x 10" sizes          
Umax 1100
42
1200x2400
8.5x10"
Photoshop 6.0
899.99
Epson Expression
36
1600x 3200
8.5x11.7"
?
901.00

There many additional desktop scanners available even different models from the manufacturers above. Connections include SCSI, USB, and Firewire and prices can vary tremendously when shopping online. You need to research these scanners very diligently and establish what your needs are before purchasing. Some of you will only want to scan intraoral films, others will want to do 35 mm slides and intraorals. Those of you who want to scan panoramic images need a scanner with a bigger surface than many of these scanners offer. The namebrands Umax, Microtek and Epson were chosen because of research I’ve done on scanner characteristics. Prices vary, bit depth varies, connections vary as well as size and software bundles. You need to do the research well BEFORE you buy!

Just remember, you get what you pay for, and you must be prepared to spend time learning the image processing for the images you scan. It’s time consuming but worth it as you move into your new digital world. Below is an image I scanned using a Umax scanner. I did some minor image processing to come up with a graphic to use for a brochure. Did I create an image with useful diagnostic information? Maybe. Did I create an image that was useful to me? Yes. Did I have fun doing it? Yes. Did it take a lot of time? No. But if I had to arrange a set of 12-20 intraoral x-rays on the scanner bed, scan them and then crop and store them individually so I could perform image processing operations on selected films to extract disease features…now THAT would be VERY time consuming. Scanning can be useful. It can be fun. You can store images by scanning. You can improve poor image quality by scanning. You can be very creative with scanning software. But, remember, you can also waste a lot of time. Indirect imaging by scanning is for specialized tasks. It is NOT a substitute for direct x-ray imaging.

 

 
© Dr Dale Miles DDS, MS, FRCD
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