Melanoma is aggressive and life-threatening. If it
is not detected early, the prospects of recovery
drop. Screening is complicated, though. Together
with several project partners, Fraunhofer
researchers have developed an assistance system that
helps dermatologists with diagnosis.
The Dermascanner scans the surface of a patient’s
skin from different positions and divides it into
around one hundred individual images. © Dirk
Mahler/Fraunhofer IFF
US Melanoma rates doubled between 1982 and 2011:
“The rate of people getting melanoma continues to
increase every year compared to the rates of most
other cancers, which are declining,” said Lisa
Richardson, MD, MPH, Director of the Division of
Cancer Prevention and Control. “If we take action
now, we can prevent hundreds of thousands of new
cases of skin cancers, including melanoma, and save
billions of dollars in medical costs.”
According to the German Cancer Society, around
200,000 people contract skin cancer every year.
Melanoma is particularly dangerous. Once it has
penetrated deeper layers of skin, the prospects of
recovery drop to less than ten percent. Routine
screening is the only way to detect critical skin
changes at an early stage.
A doctor uses a dermatoscope – a magnifier that
peers into deeper layers of skin – to examine
abnormal moles, called melanocytic nevus by experts,
for features such as size, texture and edges and to
observe whether they change over time. Since most
people have many moles, the procedure is time
consuming. What is more, keeping an eye on changes
such as the growth of individual moles is difficult
since a doctor often cannot identify them with
absolute certainty during the next exam.
At the initiative of and together with the
University Clinic for Dermatology and Venerology in
Magdeburg as well as the partners Dornheim Medical
Images GmbH and Hasomed GmbH, researchers at the
Fraunhofer Institute for Factory Operation and
Automation IFF have developed a full body
dermatological scanner intended to help doctors
diagnose skin conditions in the future. “The scanner
delivers standard data for the evaluation of skin.
At the same time, it improves documentation of the
development every single conspicuous mole,” says Dr.
Christian Teutsch from the Fraunhofer IFF.
When the exam starts, the surface of the patient’s
skin is scanned from different positions and broken
down into approximately one hundred individual
scans. Such image documentation already exists. “The
crucial point, however, is that the actual size and
changes in growth cannot be clearly discerned solely
on the bases of scans,” explains Teutsch. That is
why the Dermascanner generates additional scanned 3D
data, which are fused with the 2D scans, thus
assigning a scale to every single pixel in the
image. The experts are integrating several 3D
sensors in the scanner so that this functions.
The sensors and cameras are calibrated so that their
location in space is known precisely. The beams of
light from the camera striking the mole can be
assigned a precise 3D distance. Even when different
scans have not been taken from the exact same
distance – which is hardly likely – the doctor can
apply the scale to determine the actual proportions
precisely. The scanned data and scans are fed into
analysis software and analyzed and presorted by
automatic classification.
The software compares any existing earlier scans of
development with current images. “Our technology
detects growth upwards of half a millimeter,” says
Teutsch. Another advantage is that the scanned 3D
data enables a doctor to clearly locate every single
mole again.
“A single patient frequently has several hundred
moles,” says Prof. Harald Gollnick, Director of the
University Clinic for Dermatology and Venerology.
When such a high risk patient visits the doctor
again after a while, common methods of examination
cannot discern whether the location and size moles
on skin covered with pigmentation spots are still
identical. According to Gollnick, “The new full
body, early skin cancer detection system makes a
nearly standard evaluation of skin condition and
changes possible for the first time.”
“The diagnosis itself is and remains the doctor’s
purview,” stresses Teutsch. Doctors have both the
scan results and the scans with an additional 3D
depth map, which records the distance of the
individual pixels in the scan, at their disposal to
make a diagnosis. Since minimal changes of an
abnormal mole can already be significant, the
scanned and image data have to be comparable at any
time and also among different equipment.
That is why another important aspect of development
was the standardization of the Dermascanner –
another of the Fraunhofer IFF’s specializations. “We
calibrate every relevant element such as light
sources and convert the scans into a standard color
space,” explains Teutsch. This assures that effects
such as fading luminosity over time do not affect
the results.
For more information
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