PARS® is a Revolutionary Microscope
for In-Situ and Fresh Tissue Diagnostics.
for In-Situ and Fresh Tissue Diagnostics.
PARS® is the most advanced optical absorption microscope to date. It captures optical absorption from radiative contrast (e.g., autofluorescence), non-radiative relaxation (e.g., temperature, pressure) and scattering channels (indirect optical absorption measurement) simultaneously. Unlike other optical imaging modalities,
it delivers both functional and molecular imaging in close to real-time.
it delivers both functional and molecular imaging in close to real-time.
Benefits
NON-DESTRUCTIVE
PARS® has successfully visualized tissue structure in unstained tissue slides, frozen sections, tissue blocks, and even fresh
bulk tissues without affecting further processing. Because PARS® is non-destructive, it can be used at every step of the histological workflow, facilitating clinical adoption and easy integration into existing practices. |
ACCELERATES THE ESTABLISHED PROCESS
PARS® does not change the established histology. PARS® accelerates it by providing pathologists with the same H&E-like images they have always interpreted.
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NO LABELS OR DYES
PARS® does not require the use of labels (i.e., dyes) since it directly images the endogenous absorption of targeted chromophores. Because it is label-free, it can be used safely in-situ and intraoperatively, without requiring additional safety procedures or controls.
If labels are beneficial, PARS® will image them as well. |
REAL-TIME FEEDBACK
Unlike conventional photoacoustic modalities, speed is not limited by the time it takes for sound waves to reach the sample surface where they can be detected with a transducer. Instead, PARS® enables real-time feedback by using a detection laser to visualize chromophores right at the source.
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NO CONTACT WITH TISSUE REQUIRED
An important feature that distinguishes PARS® from conventional photoacoustic modalities is that it operates fully non-contact, allowing it to visualize the optical absorption and optical scattering contrasts in suspended media without any acoustic coupling (e.g., water or ultrasound gel) and without the need for a transducer. PARS® can be used in several clinical applications where conventional photoacoustic imaging cannot. This includes where contact is impractical (e.g., during surgery, ophthalmology) or where the working space and footprint (e.g., endoscope) are limited.
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THICK TISSUE IMAGING
PARS® employs a reflection-mode architecture that enables it to provide rapid cellular structure visualizations of optically thick samples.
This capability makes it more appropriate than transmission-mode microscopes for imaging freshly resected tissue and, in the future, in-situ clinical applications (e.g., in-situ surgical microscope, endoscope). |
3D IMAGING & OPTICAL SECTIONING
PARS® can perform 3D imaging and optical sectioning to provide up to ~20 prepared slides, saving time and resources.
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The Technology
Photon Absorption Remote Sensing (PARS®) Microscopy
PARS can capture all light-matter-interactions
(absorption, scattering and emission) to offer unique and accurate imaging.
(absorption, scattering and emission) to offer unique and accurate imaging.
HOW PARS® WORKS
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A picosecond scale pulsed excitation laser is focused into biological tissues to generate radiative (i.e., optical emissions), non-radiative (i.e., heat and pressure), and scattering effects in the sample.
Absorbed photons are captured and converted into different forms of emission from the sample (non-radiative and radiative), while scattered photons continue moving through and interacting with other portions of the sample. |
Non-radiative effects are recorded using a secondary confocal detection beam, enabling the detection of temperature and pressure changes as close to the source as possible. These changes are registered as modulations in backscattering intensity, which are then directly correlated to the local non-radiative absorption contrast.
The unperturbed backscatter (pre-excitation event) simultaneously captures the optical scattering contrast. |
All captured contrasts can then be combined or visualized separately.
PARS® TECHNOLOGY EXPLAINED
Video: The PARS® Technology explained by Prof. Dr. Parsin Haji Reza
PARS® for Histology
PARS® histology images are equivalent to Gold Standard H&E
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Histology is a routine lab technique used to study morphology and structure of cells and tissues using a transmission mode microscope. Histological studies of biological tissues establish structure-function relationships that may have diagnostic and prognostic value in clinical contexts. In medicine, histopathology includes the microscopic identification and study of diseased tissues, and is critical to cancer diagnosis.
The gold standard for cancer diagnosis and postoperative assessment of surgical margins is the histopathologic assessment of formalin-fixed, paraffin-embedded and stained tissue slides, which requires resection, chemical stabilization with a fixative, embedding in paraffin, slicing, mounting on glass slides, and staining with hematoxylin and eosin (H&E), followed by light microscopy qualitative analysis by a trained pathologist. This procedure is time- and resource-intensive (final diagnostics can take 3-14 days), expensive and requires complex administrative controls. PARS® microscopy uses UV light to virtually stain tissues, then color matches them to hematoxylin (H) and eosin (E) stains. The rigorous tissue processing and staining workflow is no longer required to achieve gold standard H&E images. |
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The PARS® Shortcut
PARS® delivers gold standard images for histology during surgery.
Tissue processing is not required.
Tissue processing is not required.
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Upper part: tumor board – evaluate histo-pathology results and eventually schedule repeat surgery (15.5%* / 32.5%**) for positive surgical margins
Lower part: evaluate surgical margins intraoperatively and prevent repeat surgeries as left positive margins are identified intraoperatively with gold standard H&E histo-pathology diagnostics |
* Adams BJ, Zoon CK, Stevenson C, Chitnavis P, Wolfe L, Bear HD.
The role of margin status and reexcision in local recurrence following breast conservation surgery. Ann Surg Oncol. 2013;20(7):2250-2255 ** Piper, M.L., Wong, J., Fahrner-Scott, K. et al. Success rates of re-excision after positive margins for invasive lobular carcinoma of the breast. npj Breast Cancer 5, 29 (2019). https://doi.org/10.1038/s41523-019-0125-7 |
More about the PARS® Technology
Learn more about PARS® technology
in our knowledge base.
in our knowledge base.