<p>Conventional cytology is a rapid chair-side method for diagnosis, but it relies on laborious fixing and staining protocols. As cytology specimens are transparent, it is very hard to visualize them under a bright-field microscope without staining. Quantitative phase imaging techniques have opened up an interesting and potential diagnostic method for volumetric three-dimensional (3-D) visualization of the transparent specimens without any need for sample preparations. We explore the use of digital holographic microscopy in clinical application of oral cytology for the 3-D visualization of buccal cells with high contrast without any additional sample preparations. We also propose nuclear to cytoplasmic (<italic>N</italic> / <italic>C</italic>) volumes as a much more accurate parameter for identification of multinucleate and actively dividing cells. We quantify the cellular volumes, and <italic>N</italic> / <italic>C</italic> ratios for 203 buccal cells taken from five healthy volunteers to clinically validate the technique and compare them with the traditional <italic>N</italic> / <italic>C</italic> area ratios as well as the histology standards. The mean <italic>N</italic> / <italic>C</italic> area and volume ratios are found to be 0.0322 ± 0.0149 and 0.0648 ± 0.0286, respectively. Our approach highlights the dawn of a new method for a label-free/nondestructive volumetric oral cytology evaluation, with high potential for exploration of suspicious oral lesions, in subjects with chronic habits such as alcoholism and tobacco use.</p>
Digital holographic microscopy (DHM) is a quantitative phase imaging (QPI) modality, which retrieves 3D object phase information. The quantification of subcellular features within the object is possible. Its single-shot hologram recording feature makes it suitable for real-time imaging applications. This paper discusses QPI capability of LED-based digital inline holographic microscopy (LDHM), which has gained much attention for its portability, cost-effective features. However, the twin image artifact is present in the inline setup. Though several twin image reduction and elimination methods are developed, the exact phase quantification is always a challenge. Original phase information may be lost after elimination of twin image. There is always a trade-off between twin-image elimination and QPI of inline microscopy setup. This paper discusses the QPI capability of LDHM in comparison with the conventional off-axis DHM. Further, the results of phase objects using both the methods are studied.