New Laparoscopic Imaging Technique Accurately Maps Biological Tissue for Minimally Invasive Surgery

By HospiMedica International staff writers
Posted on 19 Feb 2025

Image: Graduate researcher Anthony Song is shown operating the optical setup (Photo courtesy of Johns Hopkins University)

Laparoscopy, a minimally invasive surgical method, has become the standard approach for many procedures, including prostatectomies and appendectomies, thanks to its advantages such as faster recovery times, reduced scarring, and lower healthcare costs. However, the technique still faces challenges in visualization, particularly when it comes to identifying critical anatomical structures, assessing tissue perfusion, and distinguishing cancerous tissues. The limited field of view (FOV) and poor contrast in laparoscopic images often lead to subjective decision-making based on the surgeon’s experience, which can result in significant variability in clinical outcomes. These issues have driven research into optical technologies that offer more accurate and objective guidance for surgeons.

A research team from Johns Hopkins University (Baltimore, MD, USA) has now developed a new laparoscopic imaging tool to address these challenges by using advanced techniques to map tissue properties with high precision. The device integrates stereo depth estimation and speckle-illumination spatial frequency domain imaging (si-SFDI) to generate detailed optical property maps of tissues. Unlike traditional methods, this system employs a quantitative approach by measuring key properties such as absorption and scattering, enabling it to distinguish between healthy and cancerous tissue with high sensitivity and specificity.

As reported in the Journal of Biomedical Optics, the new system utilizes a compact two-camera laparoscope paired with a fiber-coupled laser to generate high-contrast speckle patterns on the tissue surface. These patterns enable the system to estimate optical properties without needing multiple images. This approach enhances measurement accuracy, especially for complex tissue geometries. Unlike earlier versions of si-SFDI, which required 10 or more images, this new method can acquire accurate data with only two image frames, making real-time mapping during surgical procedures feasible. This innovative technique offers surgeons a straightforward yet powerful tool to obtain quantitative optical property maps during laparoscopic procedures. By providing detailed tissue information, it could reduce reliance on subjective assessments, improve clinical outcomes, and enhance the precision of minimally invasive surgeries, potentially helping to identify critical tumor margins.

“Using a compact multimode fiber to generate laser speckle patterns makes speckle illumination spatial frequency domain imaging a compelling method for measuring wide-field quantitative optical properties over a large field of view, even in physically constrained settings such as minimally invasive surgery,” said Anthony Song, a graduate researcher from Johns Hopkins University.