Interview with Fabrice Harms at LLTech about high full well capacity camera for non-invasive cancer assessment FFOCT systems

Adimec and former LLTech, now called Aquyre, are two members in the CAReIOCA consortium (for more information: www.careioca.eu) that are developing & validating high-resolution, high-speed medical imaging devices toperform non-invasive optical biopsies for cancer assessment.

The optical technology used in the end systems is based on Full Field Optical Coherence Tomography (FFOCT), a technique that enables non-destructive volumetric image capture on scattering samples such as biological tissue at micron resolution in 3D.  The technology intends to assist in diagnosis, particularly of cancer, in skin, breast, prostate, brain etc., as well as intraoperative quality control of biopsies.

Adimec contributes with a specific high-performance CMOS CoaXPress camera.  The result is the Adimec       Q-2HFW/CXP which offers 2 Megapixels at over 700 fps via CoaXPress, offering an industry unique high full well capability of 1.6 million electrons per pixel.

I had a chance to speak with Fabrice Harms of former LLTech to talk about this technology in more detail:

Q. What advantages do these new cancer diagnosis systems offer compared to existing techniques?

FFOCT is the only OCT (Optical Coherence Tomography) technique that enables the evaluation of tissue at the cellular level due to its unequaled resolution.  The goal is to achieve an intraoperative diagnosis of cancer during surgery or just minutes after.  Currently this intraoperative diagnosis is based on frozen sections analysis: it entails the removal of tissue, sample prep with contrast agents, involvement of many technicians and frequent artifacts, which limit its systematic use. The final diagnosis based on histology is usually available only after several days.   When histology reveals that tumor tissue was not fully removed, it usually means that the patient must undergo another surgical procedure.  If the assessment of the complete removal of the tumor can be done during the initial surgery, as with the new FFOCT devices, the patient is still present and an iterative procedure can ensure full tumor excision. Overall this will gain time for treatment, gain comfort for the patient, and save money.

Q. What is OCT and FFOCT?

Optical Coherence Tomography (OCT) is an optical measurement technique to image scattering samples in depth, so that it is particularly adapted to biological tissue for medical purposes. It can be considered as an equivalent to ultrasonography but using light instead of ultrasound, thus allowing for better resolution but lower penetration depth.  When trying to visualize tissue at a cellular scale, standard microscopes cannot be used since scattering acts as a “fog” that hides microscopic details. OCT gets rid of this fog for accurate information with a typical resolution of 10 µm, and using appropriate scanning 3D images are possible to be acquired.  FFOCT then enables greater resolution than conventional OCT devices, typically 1µm in 3D, which gives access to cellular details.

Q. What did the Adimec camera provide that was different from general-purpose cameras available?

Adimec characterized the image sensor provided by CMOSIS, to drive the imaging performance and adapt the camera for the specific measurement needs.

For example, when compared to previous components, the new camera provides the system a factor of 5 increase in terms of speed and a factor of 3 increase in terms of sensitivity.  These specific improvements provide a better match to the clinical requirements for speed and accuracy, in particular regarding current developments in endoscopy.

Q. What are some other applications for this technique besides cancer assessment?

Other applications in the medical field include drug development by pharmaceutical companies as non-invasive measurements on small animals at the cellular level can be made.  FFOCT microscopes can be used in studying plants to understand the effects of stress or in cosmetics testing to monitor the effects of creams, etc. on the skin. Non-destructive testing is also a relevant field of applications when characterizing microscopic structures in scattering or semi-transparent samples is mandatory, for example in solar cells or for thickness measurement and characterization of polymer layers.