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:
- Archiving
your current film repository
- Recovering
older, less diagnostic
film information from
stored films
- Sending
a film image to the insurance
carrier
- Building
case material for presentation
- Scanning
35 mm slides, so why not
do x-rays too
- 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.
