The Use of Infrared Spectral Histopathology and Cytopathology.
Nora V Laver, Benjamin L Bird, Jennifer M Schubert, Milos Miljkovic, Kristi Bedrossian, Max Diem. Tufts Medical Center, Boston, MA; Northeastern University, Boston, MA
Background: Infrared micro-spectral imaging (IRMSI) is a novel optical technique that can provide a rapid measurement of sample biochemistry and identify variations that occur between healthy and abnormal cells and tissues. The advantage of this method is that it is objective and provides reproducible results, independent of fatigue, experience and inter-observer variability. This abstract provides a review of this technology applied to both cytology (Spectral Cytopatholgy, SCP) and histology (Spectral Histopathology, SHP) samples.
Design: Unstained tissue or exfoliated cells are prepared onto infrared (IR) microscope slides and analysed by IRMSI. Specimens were interrogated by a beam of IR light that samples pixels (6.25 µm x 6.25 µm in size) from areas of interest. Each recorded IR image may consist between 25,000 and 500,000 complete IR spectra that describe the discrete biochemistry of the sample at each pixel co-ordinate. Mutlivariate methods of data analysis are used to classify and diagnose the sample spectra correlated against conventional histopathology, cytopathology, IHC and viral DNA testing.
Results: Proof of concept studies have been done on various specimen types by use of SHP. These include tissue sections from cervix, breast, colon, oral, nasopharynx, lung, thyroid and lymph nodes. More recent studies have focused on the application of this technique on Fine Needle Aspirate (FNA) specimens. Currently, acquistion of spectral images from tissue micro-arrays with high patient numbers is underway to develop a robust automated spectral method for lung cancer typing. Similar studies have been done on cervical, bladder, nasopharyngeal, and oral exfoliated samples by use of SCP. Present investigations are focused on the identification of pre-cancerous stages of disease and the detection of viral infections in squamous cells of the oral cavity and cervix.
Conclusions: SCP can identify small but reproducible biochemical changes within normal and dysplastic squamous cells. This technique may aid in the diagnosis of dysplasia when the morphology is equivocal or identify pre-dysplastic changes in normal-appearing cells. In addition, SCP has distinct potential to identify the presense of viral DNA. Primary or metastatic tissues can be detected and imaged readily in biopsy tissue sections by SHP. The resulting diagnostic images can recognize micro-metastases, tissue desmoplasia, inflammatory cells and various cancer types. Optimised IR imaging instruments may allow the acquisition and diagnosis of clinical samples within a few minutes.
Wednesday, March 2, 2011 9:30 AM
Poster Session V # 212, Wednesday Morning