Confocal Reflectance Imaging of Head and Neck Surgical Specimens

Abstract

Background: Confocal reflectance microscopy (CRM) is an optical method of imaging tissue noninvasively without the need for fixation, sectioning, and staining as in standard histopathologic analysis. Image contrast is determined by natural differences in refractive indices of organelles and other subcellular structures within the tissues. Gray-scale images are displayed in real time on a video monitor and represent horizontal (en face) optical sections through the tissue. We hypothesized that CRM is capable of discerning histologic characteristics of different tissues in the head and neck. Objectives: To examine the microscopic anatomy of freshly excised head and neck surgical specimens en bloc using CRM and to compare the findings with those generated by conventional histologic analysis. Design: This was a pilot observational cohort study. Bone, muscle, nerve, thyroid, parotid, and ethmoid mu-cosa from human surgical specimens were imaged immediately after excision. Confocal images were compared with corresponding routine paraffin-embedded, hematoxylin-eosin-stained sections obtained from the same tissue. Results: Characteristic histologic features of various tissues and cell types were readily discernible by CRM and correlated well with permanent sections. However, in all tissues examined, there was less microscopic detail visible in the CRM images than was appreciated in paraffinembedded histologic sections. Conclusions: The CRM images revealed cytologic features without the artifacts of histologic processing and thus may have the potential for use as an adjunct to frozensection analysis in intraoperative consultation.

In vivo imaging of oral neoplasia using a miniaturized fiber optic confocal reflectance microscope

“…34 A study published by White et al in 1999 comparing in vivo confocal reflectance imaging of normal oral tissue with histology established the foundation for in vivo confocal imaging for disease detection in oral mucosa. 34 The confocal images presented by White et al correlated well, both qualitatively and quantitatively, with histology. Epithelial cell nuclei and cell borders, circulating blood cells, and extracellular matrix were imaged with confocal microscopy.…”

Fluorescence confocal microscopy for pathologists

“…[8][9][10][11][12][13][14][15][16] Compared with the wider use of the in vivo confocal microscopy, ex vivo tissue assessment has been performed mainly in skin oncology to examine excision margins in Mohs surgery; 17 only few studies have focused on different tissues. [18][19][20][21][22][23][24][25][26] In surgical oncology, the possibility to obtain a reliable histopathologic diagnosis in a short time represents a relevant clinical advantage for patient management. Nowadays histopathologic diagnosis is routinely rendered through intraoperative frozen tissue examination when a rapid diagnosis is required.…”

Non-Invasive Techniques for Detection and Diagnosis of Oral Potentially Malignant Disorders

“…CRM is based on the mechanism of backscattering of light. This is primarily determined by natural differences in the refractive indices of organelles and other subcellular structures within the tissues (White et al 2004). Basically, the CRM set consists of a light source, a condenser, an objective lens, and a detector.…”

“…The researchers suggested the potential of CRM in the clinical evaluation of oral lesions, early diagnosis of oral PMDs and oral cancer, real-time identification of tumor margins, and monitoring of the response to therapeutic treatment (Clark et al 2003; Anuthama et al 2010). However, in an pilot study, when the researchers examined the microscopic anatomy of freshly excised head and neck surgical specimens using CRM, and compared the findings with those generated by conventional histologic analysis, they found that there were fewer microscopic details visible in the CRM images than in paraffin-embedded histologic sections (White et al 2004). …”