microendoscopy system that can detect
abnormal changes in the cervix with
mild acetic acid staining of the tissue.
Research at the University of Arizona’s Biomedical Imaging Laboratory
has focused on laparoscopic imaging of
the abdomen, particularly the ovaries.
Currently, there is no effective screening
technique for ovarian cancer. Confocal
microendoscopic imaging of this organ
during laparoscopy might represent a
viable option for women at high risk of
developing the disease who do not want
their ovaries removed.
We have developed a rigid confocal
microlaparoscope for this purpose. It
achieves real-time 30 frames per second
imaging in grayscale mode. It can be
switched nearly instantaneously to a
multi-spectral imaging mode, which—
in the current configuration—acquires
image data from 500 to 750 nm with
approximately 6-nm resolution in about
5 s. The system uses a 488-nm laser
excitation source that is well suited to
excite fluorophores such as fluorescein
sodium and acridine orange. Motorized
focus control and a computer-controlled
dye delivery channel are incorporated
into the device. The system is currently
undergoing clinical evaluation.
Miniaturization is a
driving force that
will likely enable
access to even more
restricted locations in
the human body.
biopsy with several commercially available systems. Researchers at various
institutions continue to improve upon
the basic foundation of this technology
by developing novel approaches and
investigating new clinical applications.
Miniaturization is a driving force that
will likely enable access to even more
restricted locations in the human body.
A key advantage of this technology
is its ability to detect disease at an early
stage. The ongoing development of new
and effective contrast agents could revolutionize the way diseases are diagnosed
by shedding light on the molecular
changes that occur even before the onset
of visible disease. The high sensitivity of
fluorescence-based confocal microendoscopy, with its ability to image living tissue in situ and in real time, fits perfectly
within this conceptual framework.
A fundamental challenge for confocal microendoscopy is imaging deeper
below the tissue surface. New contrast
agents and systems working in the near
infrared or new techniques less sensitive
to scattered light could improve upon
this c apability.
The large volume of image data produced by confocal microendoscopes and
other optical biopsy techniques provides
an opportunity for increased diagnostic
accuracy but also poses a challenge for
interpretation. Automated pattern recognition software in the data stream could
help overcome this problem by automatically identifying disease and allowing
more focused scrutiny of suspicious areas.
Ultimately, real-time diagnosis
provided by optical biopsy creates the
potential for integrated treatments that
are specifically directed to the site of the
disease. Combined diagnostic and therapeutic systems are a logical next step in
this rapidly evolving technology. t
Arthur F. Gmitro (gmitro@radiology.
arizona.edu) is the director of the University of Arizona’s Biomedical Imaging Laboratory in Tucson, Ariz., U.S.A. Andrew R. Rouse is
on the lab’s research faculty.
Confocal microendoscopy is an established imaging technique for optical
5-mm-diameter igid probe
Flexible cable to
optical scan unit
Four push-button controls
located on the handle allow the
surgeon to adjust the focus,
deliver contrast agents, save
still images and record videos.
Inside the handle, two motors
control focus and dye delivery.
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