The Principles of Clinical Cytogenetics - Extra Materials - Springer

120 Steven Gersen and Lotte Downey
metaphase finding or fluorescent spot counting) also represents a growing application for imaging
systems in cytogenetics.
Benefits
Reduction in the time it takes to complete an analysis is unquestionably the major benefit of an
automated imaging system. Laboratories can save operator time by automating metaphase scanning,
karyotyping, and FISH applications, resulting in a faster turnaround time and higher throughput of
cases. Reduction in labor also translates to reduced costs.
Another big advantage of digital images is easy and compact storage. Some states require storage
of patient cases for up to 100 years! With current compression technologies and digital storage
devices, this is easier and less space-consuming than with photographs. In addition, photographs can
deteriorate over time, making them harder to re-examine if necessary.
Automated imaging systems also provide consistency, especially when performing interphase
FISH assays. Whereas manual spot counting can be highly subjective and error-prone, an automated
system will use predefined parameters for spot counting and, using those parameters, will produce
consistent results.
Sharing of data is important in a clinical lab setting and is clearly facilitated by the use of digital
images versus traditional photography. With the growing use of the Internet and electronic mail,
digital images are more easily shared for consultation and discussion (2). However, with data sharing
via the Internet comes the need for compression, and a more pressing need for patient record security.
Partly to address this need for patient record security, the US Congress recently passed the Health
Insurance Portability and Accountability Act (HIPAA) (3). See also Chapter 6.
Although traditional photographic techniques offer some degree of contrast and other image adjustment,
automated imaging systems further offer easy image enhancements, visualization techniques,
and quantification, providing additional information. As stated earlier, recent advances in cytogenetic
applications, especially in FISH applications such as M-FISH, CGH, and interphase FISH can
be attributed to imaging systems.
Limitations
Of course, there are limitations to automation in the cytogenetics laboratory. Probably the greatest
limitation is the interpretation of the karyotype or FISH results and the diagnosis based on the analysis
of the image. This will still be a task for the Director. Another limitation is that despite image
enhancement features, the quality of the final image is still dependent on the quality of the original
microscope image (2). An image might be improved through background elimination, contrast, and
color enhancement or even longer exposure times, but all of these will not make up for a poor image
resulting from poor microscope configuration or slide preparation.
Imaging System Components
In general, an imaging system for cytogenetics contains the following components: a microscope
with camera adapter, a camera, computer and software, a printer, and an archival device. (See Fig. 7.)
Microscope with Camera Adapter
A detailed discussion of microscopes and microscopy can be found in Chapter 5. As the name
already implies, the camera adapter is the device designed to attach a camera to a microscope. This
adapter also permits the microscope image to be projected onto the photosensitive area of the camera.
Camera
Although a wide range of camera options are available (analog, digital, cooled, uncooled, monochrome,
color), the most commonly used camera on automated imaging systems for the cytogenetic
laboratory is a black-and-white, uncooled CCD (charge-coupled device) camera (4).