(G-259) Rapid on-site evaluation of thyroid fine needle aspiration using a parallelized 16-gigapixel microscope

Introduction:: The application of digital pathology methods for the study and analysis of thick cytology specimens, such as fine needle aspiration smears, is challenging. As compared to thin tissue sections, the large area and 3D nature of thick cytopathology smears present challenges to existing slide scanning technologies, including the introduction of long scan times. We developed a novel multi-camera array microscope (MCAM) that can perform rapid 3D imaging over large areas, similar to high-end whole-slide scanners, but at a significantly higher speed. To test the performance of our MCAM imaging hardware, we chose a simple task, determining the adequacy of thyroid samples. This task is a common one for which rapid on-site evaluation (ROSE) is used. The MCAM’s ability to rapidly digitize thick smears has the potential to save time and facilitate other digital cytology applications.

Materials and Methods:: The MCAM imaging system consists of N=48 sets of individual digital image sensors and matching custom-designed 10x resolution equivalent lenses, which rapidly image whole slides in 3D in a parallelized manner. The MCAM enables capturing image data faster than a traditional microscope at the same resolution, by decreasing the need for lateral scanning. This improves the speed of digitization and decreases the delay in whole-slide visualization. The system can automatically digitize 3 whole slides in 3D within 15 minutes, which covers a 6 x 8 cm2 area and a 100 um thickness. MCAM software generates all-in-focus 2D images eliminating the requirement to manually annotate or choose areas on a slide.

Results, Conclusions, and Discussions:: For the ROSE task, 26 unique anonymized Diff-Quik stained smear slides from adequate and inadequate thyroid samples were imaged using the MCAM and displayed within an interactive viewer to a pathologist for review to determine adequacy. Decisions via digital slides were compared to adequacy determination using the glass slide.

18 smears (69.2%) were deemed adequate and 8 smears (30.8%) were deemed inadequate. The sensitivity of this MCAM-based ROSE in determining adequacy was 75% and specificity was 100%. For McNemar’s test, statistic S was 0.5, the degree of freedom was 1, and the probability of random agreement (Pr) > S was 0.48. The simple 𝜿 coefficient was 0.81.

Our MCAM system is capable of rapidly imaging 3D cytology smears, with resolution that allows the performance of a common cytology task. This study establishes the utility of the MCAM system as a novel tool for digital cytopathology applications.

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References (Optional): : Harfouche M, Kim K, Zhou KC, Konda PC, Sharma S, Thomson EE, Cooke C, Xu S, Kreiss L, Chaware A, Yang X. Imaging across multiple spatial scales with the multi-camera array microscope. Optica. 2023 Apr 20;10(4):471-80.