Digital Imaging in Dermatology
Tuesday, December 06, 2005
For dermatologists, high-quality care depends on detailed
visualization that allows comprehensive examination and accurate
diagnosis. Accordingly, digital photography is becoming an
essential tool in dermatology care delivery.
"I use digital imaging every day in my office," says Ashish
Bhatia, MD, a dermatologist with the DuPage Medical Group in
Naperville, Ill., and a clinical professor of dermatology at
Northwestern University. "And I use [the technology] in different
ways for different patients."
For example, Bhatia uses digital photography for Mohs surgery.
In a process that spares as much normal tissue as possible, he
conservatively removes malignant tissue, then takes a photograph.
If the magnified digital image shows residual malignancy, he
removes more tissue and takes another photograph. Bhatia also uses
photos to track subtle changes, like those that occur with laser
treatments for acne scarring.
At Skin & Cancer Associates in Miami, Harold Rabinovitz, MD,
uses digital images to evaluate patients at high risk of melanoma.
A professional photographer takes standardized full-body
photographs, which Rabinovitz uses as a baseline for further
examinations. "When you have a patient with many moles of different
sizes, shapes, and colors, it's difficult to see if they have a new
mole or if an old mole has changed," he says.
Rabinovitz also uses digital images for education. As a
volunteer professor of dermatology at the University of Miami, he
says, "It's easier to carry a memory stick than six trays of
It's also easier to e-mail image files to other specialists for
consultation and evaluation. "When a patient has a mole or
pigmented lesion, sometimes the pathologist is aided by a photo.
When reviewing the pathology, he has an image to help him with
decision-making," Rabinovitz says.
Bhatia's staff even send him photos when he's out of the office.
For example, if a physician assistant (PA) removes sutures and is
concerned about the condition of a wound, the PA e-mails a photo to
the dermatologist for evaluation. "I can even look at them on my
phone. It's kind of cool," says Bhatia.
Digital or standard?
Industry estimates indicate that two-thirds to three-fourths of
dermatology offices currently use some type of digital photography.
Although the goal of both digital and standard photography is to
take clear images of lesions to ultimately improve condition
tracking and outcomes, the primary reasons for the migration to
digital imaging are cost and simplicity.
Robert Brodell, MD, a dermatologist in Warren, Ohio, and
associate professor at Case Western Reserve University, used to
spend at least several thousand dollars annually on film and
processing. Then he decided to go digital. After an initial
investment in cameras, accessories, and related computer hardware
and software, Brodell's ongoing photography costs have dropped to
Digital photography also saves time. Photos for patient records
are available immediately. Instead of waiting days for slides for
presentations, Brodell now imports digital images directly into his
software in minutes.
Several emerging technologies are close to becoming standard
tools, according to Rabinovitz:
- Digital dermoscopy - A Sydney, Australia-based company,
Polartechnics, has developed a digital dermoscopy camera called
SolarScan, which captures and analyzes images of pigmented skin
lesions and presents information for clinical evaluation.
- Machine vision - The MelaFind machine vision system from
Electro-Optical Sciences in Irvington, N.Y., is a hand-held device
that emits multiple wavelengths of light to capture images of
suspicious pigmented lesions. The extracted data are analyzed
against the company's proprietary database of melanomas and benign
lesions using algorithms to provide information and treatment
recommendations. The system is slated for FDA evaluation.
- Confocal microscopy - Confocal laser scanning microscopy sends
a near-infrared laser beam into human skin; the beam is
backscattered to a detector that generates a digital image. The
FDA-approved VivaScope 1500 from Lucid, Inc., in Rochester, N.Y.,
provides cellular-level images - what the manufacturer calls an
Like most technologies, digital photography is not without
flaws. The most common complaint, according to Bhatia, regards the
use of image manipulation software. Many dermatologists edit images
to show patients how they might look after a procedure. If a result
doesn't look like the photo, patients may get upset.
"Be careful about controlling expectations," Bhatia says. "You
should have a written disclaimer that says actual results may
Once the basic components listed below are in place, monitoring
patients' skin conditions with an eye toward improving outcomes
will be a snap.
- Digital camera - The foundation of your system. Units vary
widely in price and features, but most now deliver clinical-quality
images. Cameras with higher resolution are better for large images,
such as full-body shots.
- Camera accessories - Lights, lenses, filters, flashes, and
tripods can be used to improve the quality of digital photography.
Specialty accessories are also available for dermatologists, mounts
for facial photography and attachments for dermoscopy and
- Power source - Most cameras use regular batteries, rechargeable
batteries, or rechargeable battery packs. Most also come with AC
adapters for recharging.
- Removable storage media - Most digital cameras use some kind of
removable, reusable memory stick. Memory sticks with greater
storage capacity can hold more images or the same number of images
at higher resolution.
- Image transfer device - Most digital cameras allow transfer of
images directly from the camera or removable storage media. Some
cameras have docking stations that connect them directly to a
computer for image downloading; others allow connection to the
camera via USB cable. Other transfer devices include adapters for
memory sticks or PC cards for slots commonly found on laptop
- Image cataloging and editing software - Software packages that
facilitate database storage, retrieval, and modification of
- Computer - The computer used for image viewing should be
equipped with a high-resolution video card, sufficient disk space,
and at least a 17-inch high-resolution monitor.
- Mass storage/backup device - Optical disc and tape drives are
the most common storage devices. Compact discs provide more rapid
access to individual files, but tapes store more data at a lower
cost per megabyte.
- Printer - Liquid inkjet printers on photo-quality paper produce
photo-quality prints at the lowest cost. Dye sublimation printers
produce higher quality prints, but the cost per page is higher.
Color laser printers, solid inkjet printers, and thermal wax
transfer printers are not suitable for photo printing.
Tips for improved digital photographs
Before completing medical school, Bhatia was a digital imaging
consultant for nearly a decade. He offers these tips for improved
digital photographs - and improved condition management:
- Use a standard background - Bhatia recommends a black
background - either a square painted on a wall or a pull-down
- Take photographs in a windowless room - This allows control
over lighting without having to account for various types of
daylight (eg, sunny, hazy) that enter through a window.
- Make sure camera and subject are always in the same place -
Place marks on the floor to ensure image consistency. This is
especially important for images of a single patient taken over
- Have patients remove all makeup and jewellery - These can cover
skin problems or create reflections that compromise image
- Set up a dedicated studio if office space permits. This allows
practices to set up special, permanent lighting to highlight subtle
textural skin changes.