GENERAL QUESTIONS
What protection do you have against hardware failures causing image loss?
The Catella image network system is robust and has many safeguards to help protect against image loss due to hardware failures. Throughout the network architecture there is an extensive use of “handshake algorithms”. When an image is transferred from one piece of hardware to another the sending hardware sends a message requesting the acknowledgement of receipt of image and the receiving hardware sends the appropriate reply. If a reply is not received the sending hardware continues to attempt to send. If after many tries and over a length of time it is not successful, then the failure will be reported to the Image Gateway and our archive system.
What are typical transmission times for different types of images?
The answer depends on the speed of the transmission line. Here are sample image transmission times in seconds (using our lossless compression) assuming different types of images and different speeds:
Image Type: |
128 k |
378 k |
512 k |
768 k |
1500 k |
|
|
|
|
|
|
Low resolution MR/CT (256x256) |
4 |
1 |
1 |
1 |
1 |
High resolution MR/CT (512x512) |
16 |
6 |
4 |
3 |
1 |
Digitized film (10 meg) |
328 |
111 |
82 |
55 |
28 |
Can Catella communicate with RIS and HIS systems?
As long as these systems are based on the HL-7 standard there should be no problems. If the system is not, please contact us. We have developed “work arounds” for other similar situations.
Can film savings really pay for a digital system?
The dramatic drop in costs of digital equipment now allows imaging centers to convert to softcopy viewing and archiving without any investment whatsoever. In fact, major operating savings can now be realized, as well. Significant additional advantages, such as increased physician productivity, savings on darkroom operations, elimination of environmental issues surrounding film processing, and faster reporting to referring doctors don't even need to be factored in to the financial analysis. There is more than enough savings just from the film budget to pay for the entire conversion to digital imaging.
To illustrate this, consider an imaginary medium-sized imaging center. Our center has one MRI, one CT, one ultrasound machine, one CR device, and one digitizer. The resolution on all modalities is assumed to be 512 by 512. Table I shows the volume and size of each study. According to Table I, 11,000 sheets of film are used per month at this facility. An approximate cost of the film and chemicals is $2 per sheet. This imaginary facility uses $22,000 per month in film.
Table I: Total Film Usage per Year
Modality |
Studies per Month |
Images per Study |
Images per Film |
Films per Study |
Films per Month |
MR |
600 |
150 |
16 |
9 |
5,400 |
CT |
600 |
60 |
16 |
4 |
2,400 |
Ultrasound |
400 |
50 |
16 |
4 |
1,600 |
CR |
200 |
4 |
1 |
4 |
800 |
Digitizer |
400 |
4 |
1 |
4 |
800 |
Totals |
2,200 |
|
|
|
11,000 |
As calculated in Table II, the amount of digital storage needed for this center is less than 600 gigabytes per year.
Table II: Total Digital Storage Required per Year
Modality |
Studies per Month |
Images per Study |
MB per Image* |
MB per Study |
GB per Month |
MR |
600 |
150 |
0.256 |
38 |
22 |
CT |
600 |
60 |
0.256 |
15 |
9 |
Ultrasound |
400 |
50 |
0.256 |
13 |
5 |
CR |
200 |
4 |
4.000 |
16 |
3 |
Digitizer |
400 |
4 |
5.000 |
20 |
8 |
Totals |
2,200 |
|
|
|
47 |
* 2:1 lossless compression is used for image storage
Our imaginary imaging center does about 100 studies per day. It needs one or two radiologists. Our current clients typically share one workstation for two radiologists. The center will need an archive sized for two years of storage (complete with redundancy) and a digitizer. Some film will still need to be printed. Most imaging centers currently have a DICOM film printer, but for our example we will assume the need to purchase a printer. Thus, for all equipment needed, including storage of all images for the next two years, the total retail price is $200,000. This system is paid for using the first nine months' film cost. But, it keeps on storing images for another 15 months. At the end of two years, the center has SAVED $328,000 .
Conversion to digital imaging will result in even more significant operating savings in future years. The cost to upgrade the archive to handle additional images would be less than $20,000 per year at current prices. (History shows that these prices will continue to drop rapidly.) This replaces approximately $264,000 yearly film costs, resulting in more than $240,000 operating savings each and every year!
In other words, after saving over 75% of the first two years' film budget, less than 10% of each additional years' film budget would be needed to support hardware expansion of the system. This analysis does not include the extra digital costs of service (12% of the equipment price per year) and human resources. However, it also excludes the extra film savings of actually storing and retrieving film which includes personnel to retrieve, hang and re-file images as well as lost films and re-takes avoided by digital imaging.
The increase in the bottom line for a medium sized imaging center is dramatic. Give AMS one half of your film budget for the first eighteen months and it will move you completely to digital imaging. After that, cut the payment to AMS in half again and it will keep the entire system running and current.
Is it costing you $20,000 per month to wait for digital imaging?
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