Home - Knowledge
Center - Healthcare Technologies
- Enabling Healthcare Technologies
DIGITAL IMAGING
Since its introduction in the mid 1970s, digital imaging has
grown to become the bases for most radiological diagnosis. The rapid progress
in the computer based imaging techniques in the last twenty years has been
fuelled by the introduction of the modalities such as Computed Tomography
Imaging (CT Scan), Magnetic Resonance Imaging (MRI), digital angiography,
ultrasound and nuclear medicine imaging.
Digital images are more often represented by large rectangular
grids comprising of individual pixels (picture elements), each with its own
bit-depth value that informs the computer, which color the pixel, should be
displayed. The digital image is then created by the culmination of all the
pixels.
advertisement
Issues arising from the storage and retrieval of digital
images in hospitals led to the development of the Picture Archiving and
Communication Systems (PACS) and Radiological Information Systems, where the
images are stored in computed formatted memory discs and can be viewed from
computer screens across a hospital or local area network.
The transfer of digital images across a network is made
possible by a standard called DICOM
(Digital Imaging and Communication in Medicine), which was developed by
the National Electrical
Manufacturers Association (NEMA) This standard allows imaging systems
to connect a central storage and/or health information system in a consistent
manner.
A basic digital imaging system would consist of the following:
-
Digital Camera: - This the basic tool required for a digital imaging system in
a clinical setting. There are many digital cameras available and those with 3 -
4 megapixels of resolution, flash capabilities and close up lenses usually
produce the best images. Images captured by the cameras can be transferred to
the computer directly using serial connections, Universal Serial Bus (USB)
ports and FireWire, or using removable storage media such as Personal Computer
cards, SmartMedia cards, Compact Flash cards or Sony Memory Sticks.
-
Computer: - A computer with a high RAM speed and high-resolution video monitor
is usually ideal for any work with digital images. Darron Spohn’s article –
Choosing a Computer System for Digital Imaging is a good place to start for
those seeking to buy a computer for digital imaging work.
-
Imaging Software: - There are many commercially available software packages
available for editing and archiving digital images.
-
Printers: - There are various types of printer now available, mainly classed
according to the technology they use to print out document pages. The inkjet
printer offers the production of realistic images on paper at a reasonable
cost. Dye sublimation printers also produce high quality reproductions but are
expensive.
The use of digital imaging by healthcare organisations
provides advantages over the use of other imaging techniques. Though the
initial cost of investing in digital imaging systems might appear higher, it
does present overall cost savings over a period of time. These savings in
particular include that of the purchase of film and chemical as well as the
processing costs, which are not incurred with the use of digital images.
Digitals images also take up less storage space than less
conventional photography, and are also easier and less time consuming to sort
and retrieve for viewing. Digital images also tend to last longer as they do
not degrade or lose colour over a period of time.
A major advantage is in the use of digital images as a
teaching tool, as they present a wide range of possibilities in the style,
format and delivery of the lectures, which can be tailored according to the
audience.
|