Filmless - The Integration of Filmless Radiology in a Resorative General Practice

A new faster, safer era has evolved for radiology in the dental office. This paper is a review of the latest technology that enables dentists to integrate filmless radiology into their practices.

Digital radiology was introduced to the dental profession several years ago. Important features include reduced radiation exposure to patients, speed of image capture and elimination of the darkroom. The dental office can now provide a safer diagnostic procedure while maintaining or improving image quality. The digital image is available almost instantly for the dentist to view and can then be stored electronically on a computer hard drive. The images can be sent electronically between dental offices and around the world via the Internet. Photo-quality hard copies can be produced whenever desired on a choice of widely available inexpensive printers.

There are three types of systems used in dental digital radiology. Each offers advantages and limitations that will be discussed in this article. Two of the systems create digital images that dramatically reduce radiation and eliminate film. One type of digital system uses a mouth sensor and a cord connected to a computer to display a digital x-ray image on the monitor.¹ The second type of digital system is cordless, using a storage phosphor transfer image plate, which after laser scanning integrates digitally into a computer and displays the image on a monitor.² The third type is a hybrid system that involves digitizing existing x-rays by the use of a hardware scanner and scanning software, which converts existing films into a digital image for display.³

All three systems require a computer with Microsoft Windows 95 or 98 software and a monitor. Copies of the digital images can be enhanced with the software tools common to each of the digital image systems. The digital x-ray images can be stored electronically.

Photographic quality copies of digital radiology from any of the above discussed systems can be produced on high dot-per-inch ink jet printers using photo quality coated ink jet paper. Each office develops their own criteria for printing and dispensing appropriate digital images. These image copies are currently accepted by most insurance companies as documentation of treatment similar to conventional x-ray film. Issues of possible fraud or manipulation of records are matters that will be more well-defined legally as the number of dentists adopting digital radiology as their standard of care increases.

Important Considerations

A number of questions are worthy for each dental practitioner to review and answer when considering a major decision such as introducing digital radiology into the office. For example:

• Is your office computerized with a Widows 95 or 98 software management system?
  
  
• How soon do you envision implementing this important improvement?
  
  
• At what future time will you consider placing computer workstations in your treatment room?
  
  
• What are the ball-park cost estimates for hardware, software, and wiring of your computer upgrades, dental office management systems and digital radiology, and how much will it cost to train your staff how to use them effectively?
  
  
• How do you plan to store and retrieve this important digital clinical information?
  
  
• If choosing a total digital radiology replacement system, what will you do with your present darkroom and equipment?
  
  
• Where will you place the new hardware with consideration for ease of access for key personnel including the dentist, hygienist, and chairside assistants?
  
  
• Have you considered developing a backup plan for a computer network crash or loss of electricity?
  

Fig 1. Most of the current available digital radiology systems use a hard sensor at the end of a cable, which connects to a computer.

Fig 2. When the sensors and connecting cord unite with image software, quality images appeaear instantly on the computer monitor.

Advantages Of CCD Radiology

High-quality images similar to film is obtained within seconds of the reduced radiation exposure. The hard sensor is easy to cover with a disposable barrier. The hard sensor can be utilized thousands of times before the need for replacement. A choice of software and sensor design is available from several competitive vendors. Darkroom chemicals are not used in CCD technology eliminating this expense and hazard. This technology is the leader where speed of image production is desired.

In the author's practice, CCD digital radiology is an important part of daily clinical practice for rapid completion of endodontic and implant procedures. Staff and patients alike welcome this instant information as well as the positive improvement of reduced radiation.

Disadvantages Of CCD Radiology

The apparent ease of use of CCD digital technology is sometimes detracted by the sizes of the various hard sensors in relation to some human mouths. A hard sensor will not fit some locations in the oral cavity. This may require an alternate digital backup system or possibly retaining conventional film. Also, multiple hard sensors are needed, which is expensive. Special holders and advanced training are required for the use of CCD sensors In obtaining a full mouth series of images, the cord or hardwire is sometimes in the way. In daily utilization, there is the danger of damage to the expensive sensors. Each office must make its own plan for the investment in digital radiology.

In the author's experience, CCD technology is cumbersome to use daily for high-volume radiology, such as the new patient examination (32-40 exposures) and recare x-ray examinations (24-36 exposures), because of the bulky stiff sensors, cords, and special holders.

Cordless Digital Radiology (Storage Phosphor)

The newer cordless digital radiology systems use a storage phosphor technology that has been available in medical x-rays for many years. Breakthroughs in laser scanning technology have permitted the creation of a practical cost effective system for dentistry (Fig. 4).

The storage phosphor imaging plate holds an image when exposed to a reduced radiation x-ray beam during the radiographic process. When the imaging plate is exposed to light of appropriate red wavelength, the image is released as blue light. When the imaging plate is optically scanned with a laser of appropriate red wavelength, the emitted blue light is simultaneously read via a photomultiplier tube. The resulting signal is electronically processed via software to produce the digital image (Fig. 5).

Fig 6 The scanner can hold a choice of two different sytles of image-holding carousels.

The Laser Scanning Container

The key equipment piece of the new storage phosphor system is the laser scanning container.⁴ The scanner can hold a choice of two different styles of image-holding carousels (Fig. 6). The intraoral carousel holds up to 29 imaging plates of all conventional film sizes. Its design is to hold more than a typical full mouth series. The panoramic carousel will hold popular size panoramic imaging plates and additionally some intraoral image plates. A cephalometric carousel will be available in the future.

Fig 8 & 9. The scanned image on the computer screen has a quality equivalent to film.

The carousel is loaded with the storage phosphor screen in a low light condition but does not need a dark room . To scan the images, the loaded carousel is placed into the laser scanner. One to three minutes later the scanned image is on the computer screen.

The image quality is equivalent to film (Fig. 8 & Fig. 9).

Scanning does not remove all of the image information from the imaging plates. Therefore, the first step in using the storage phosphor system is to erase the imaging plates. This is performed by exposing them to intense light for a minimum of two minutes. Fluorescent light sources are twice as efficient as incandescent sources at erasing imaging plates. An easy way to erase storage phosphor screens is to store them on an x-ray view box, with the light on (Fig. 10).

Fig 10. An easy way to erase storage phosphor screens is to store them on an X-ray view box witht he light on.

Additional exposure to light beyond two minutes does not hurt the imaging plates. However, if erasure is not complete, a ghost image from a previous exposure may appear.

Applications of Storage Phosphor Radiology

The cordless digital radiology system will be popular with general practitioners for the new patient x-ray examination. The system will be useful on returning patients for updating their x-ray examinations at their recare visits.⁵

Each office can continue to use existing x-ray equipment and simply turn the radiation down 60 to 80 percent compared to D-speed film. The individual storage phosphor image plate is placed inside a disposable barrier. Since it is the same size as film, it then can be placed on any film positioning device. The panoramic image plate is placed in the standard cassette and used as usual with the current intensifying screens that lower the radiation dose. The storage phosphor digital x-rays can be printed and sent with the paper insurance claim.

In the near future, the digital images will be sent electronically with the electronic insurance claim.

Advantages Of Storage Phosphor Radiology

The storage phosphor system delivers high quality images equivalent to film. The system is so flexible it is difficult to over- or under-expose an image. There are no chemicals, thus the problems associated with underdeveloped films are eliminated. There is no longer a need to dispose of lead and toxic processor chemicals. The storage phosphor transfer systems present a total replacement solution to eliminate all film, chemistry, the processor and the dark room.

The storage phosphor system image plates have the characteristics of film without film's attendant limitations. Differences in resolution due to current laser scanning limits can be overcome by the image software tools. The imaging plates are as thin as a piece of film and more flexible. The imaging plates come in all the same sizes as film: 0, 1, 2, 3, and 4, both panoramic sizes, and cephalometric plates. The imaging plates simply take the place of film, allowing the use of current x-ray equipment in its place. The reusable imaging plates are not damaged by x-rays, scanning or the erasing process. They can be reused thousands of times. The only thing that limits the life of an imaging plate is damage which might occur during use that causes creases or scratches, and that type of damage requires replacement.

In the author's experience, the busy dental practice may need approximately 75-100 storage phosphor screens for daily utilization. This number must be prepared, erased and stored daily in readily available light-proof containers. The initial investment in this large number of screens is quickly offset by the fact that they can be reused thousands of times. A part-time employee can be trained and assigned this task. The laser scanner and image file server is located centrally to the dental hygiene treatment areas and/or new patient examination rooms. Developing flow systems for implementation, coupled with adequate training and planning for a convenient location, can eliminate staff resistance to this new technology.

Disadvantages Of Storage Phosphor Radiology

To obtain storage phosphor images on the monitor takes one to three minutes of laser scanning time depending on number and/or size. The image plates must be hand packaged in disposable barriers for the quantity required in daily use. In the dental office, space and location for the laser scanner container must be well planned for easy access. The initial investment in digital radiology is a disadvantage that must be overcome with individual office planning and priority decision making.

Hybrid System

Newly improved scanning software allows the dental office to digitize existing film radiographs as well as patient paper files. It requires a high-quality scanner with a transparency module integrated and connected to a computer and monitor.

Applications of Hybrid Systems

The dental office can digitize existing x-ray and paper files to incorporate them and form complete electronic or computer files for each patient. This digital information can be printed and sent with paper insurance claims. In the near future, the digitized images will probably be sent electronically and included with the electronic insurance claim. The software has expansion modules for computers that are network-connected to the scanning computer. An additional option to the network workstation viewing is to add the capability to capture video camera images directly into the scanning software.

Advantages of the Hybrid System

The use of scanning software can be a beginning step to becoming a digital dental office. The ability to convert existing records into a digital format is of great value. The hybrid system allows the dental office to develop digital radiology reproductions. It allows use of single computer and monitor to collect and store digital information. It trains the office staff in various new computer applications.

The author finds the ability to utilize scanning software and hardware an advantageous way to digitize and integrate valuable existing clinical records: A part-time employee can scan in five to 10 patient records daily, so in a matter of months an advanced computerized office can benefit from extensive on-line digital files. It is important to install and adhere to a comprehensive backup method to store and preserve digital files. High-speed backup tapes are available today to utilize on computer file servers to provide this protection. Software and/or hardware providers are a good source of information for backup systems.

Disadvantages of Hybrid Systems

Converting existing film x-ray files is a time-consuming process. Labor expenses to accomplish this process need to be calculated. Not all dental offices may wish to accomplish this process. A digital radiology system choice will still be a requirement in order to become a filmless dental office. The quality of the reproduction is dependent upon the quality of the scanning hardware and software. An investment in hardware and software is required.

Setup Options

All three systems are available in two setup options: A stand alone system or networked systems.

The stand-alone option is useful for smaller offices. The computer, monitor and support equipment can be placed in a central area or directly in the operatory. Diagnosis takes place at the monitor.

Microsoft Windows 95, 98 or NT networks will be useful for larger offices.^6,7 The dedicated image file server and support equipment are placed in a central location. A computer and monitor are placed in each treatment room for diagnosis and any other locations desired for record keeping. A local area network is installed in the office configured to be client/server or peer-to-peer. A dedicated image file server is recommended in addition to the network file server. This allows the images to be accessed from the workstations located throughout the dental office.

Staff Training

In the CCD system, an important consideration is the significant learning curve for doctor and staff to use the cord and sensor components. New exposure techniques and special holders are often required to make the CCD systems work in the dental office. Several hours of added training are necessary for offices to implement CCD technology. A benefit of CCD-derived images is the availability for viewing in a matter of seconds.

Offices report 30-60 minutes of learning time per staff person to implement the storage phosphor digital system. The staff continues to use the same techniques in which they are currently trained. The same film holders existing in the office can continue to be utilized. Simplicity of use and ease of integration is a benefit of cordless technology.

In the hybrid system, use of hardware and scanning software can be learned in one to two hours. The actual digitized images are available for display in approximately one minute. Staff and patients will benefit from the ability to integrate office record systems.

Summary

The two systems of filmless digital radiography fulfill the promise of reduced radiation for the digital dental office. Both systems can utilize existing x-ray equipment and produce high quality digital images on a computer screen equal to conventional films. The hybrid system retains your present film-processing unit and allows converting existing x-rays into a digital format for display and storage. All three systems require a computer with Microsoft Windows 95 or 98 software as well as their own image storage software and support equipment.

Future improvements in the CCD digital systems may bring more flexible cords and thinner sensors. The cordless storage phosphor screens may come prepackaged and be less susceptible to low light. The hybrid system will offer faster scanning of existing x-rays and paper files with improved reproduction quality and greater detail.

By early in the 21st century, which is almost here, it will be possible to have all dental records formatted and stored on a computer and quickly accessible at any location desired in the dental office. The new millennium can bring the realization of a seamless transition to a paperless, filmless dental office.

Author

Arlen D. Lackey, DDS maintains a private practice in Pacific Grove, CA with an emphasis on restorative and cosmetic dentistry. He is a past president of the American Academy of Dental Practice Administration and past board member of the American Academy of Esthetic Dentistry.

References:

1. Product Literature, Dentsply New Image, Dentsply International, Inc., York, PA.

2. Product Literature, Dentsply International, Gendex Dental X-Ray Division, Des Plaines, IL.

3. Product Literature, Televere Systems, Los Gatos, CA.

4. Lackey AD, Digital Radiology. Contemp Esthet and Restor Pract 2(5), September/ October:xx-xx, 1998.

5. Lackey AD, In-Your-Face Interface is the Hub. D Econ 87(8):xx-xx, 1997.

6. Lackey AD, A New Information Base: Integrated and Networked Computers. CDA Journal 22 (9):xx-xx, 1994.

7. Lackey AD, Treatment Room Computers: Enhancing Scheduling, Examination and Recordkeeping. CDA Journal 22 (9):xx-xx, 1994.

To request a printed copy of this article, please contact / Arlen D. Lackey, DDS, Monarch Dental Building, 675 Pine Avenue, Pacific Grove, CA 93950.