# Optical coherence photoacoustic microscopy for 3D cancer model imaging with AI-assisted organoid analysis

## TL;DR

A new imaging system combines optical and photoacoustic techniques with AI to study 3D cancer models more effectively.

## Contribution

A multimodal OC-PAM system with AI algorithms for longitudinal tracking and rare cell detection in 3D cancer models.

## Key findings

- OCM with AI algorithms enabled segmentation and viability classification of breast cancer organoids over time.
- OC-PAM imaging revealed the distribution of melanin-positive cells within spheroids containing melanin-negative cells.
- The system provides robust, label-free 3D imaging with enhanced contrast and quantitative analysis capabilities.

## Abstract

Cancer organoids and cancer spheroids are 3D cell culture models with distinct yet overlapping purposes in cancer research. Various commercially available optical imaging techniques have been employed to study these cell cultures, but these methods suffer from various limitations such as the requirement of fluorescence labeling, complicated sample handling, and limited image volume size. In this work, we demonstrate a multimodal optical coherence photoacoustic microscopy (OC-PAM) system for the study of these models, overcoming these limitations. We first performed a longitudinal study using optical coherence microscopy (OCM) for breast cancer organoids. Using the OCM imaging results, artificial intelligence (AI)-based algorithms were developed to automatically segment individual organoids and classify their viability over time using a radiomics texture feature approach, enabling robust, quantitative tracking and classification at the single-organoid level. To supplement OCM’s contrast, we then performed OC-PAM imaging of spheroid models with both melanin positive and melanin negative cells. In the second study, the OC-PAM images clearly mapped the distribution of melanin positive cells hidden amongst melanin negative cells. These results suggest that OC-PAM coupled with AI techniques can be a powerful tool to study cancer organoids and cancer spheroids.

Optical coherence microscopy with AI assisted algorithms is used to track organoids and their viability longitudinally. Photoacoustic imaging adds rare cell detection function to the 3D cell culture analysis toolbox.