Tag Archive for: Richard Cha

collage of hyperspectral imaging (sHSI) camera and brain surgery

Novel camera + machine learning = hope for more precise neurosurgery

collage of hyperspectral imaging (sHSI) camera and brain surgery

Researchers at Children’s National Hospital developed a compact imaging camera capable of seeing beyond the human visual spectrum to help segment healthy brain tissue from tumors during surgery. The groundbreaking technology will allow neurosurgeons to make more precise, real-time decisions in the operating room, rather than sending samples to pathology labs for biopsies.

In a manuscript published in Bioengineering, the team of engineers and neurosurgeons details how its snapshot hyperspectral imaging (sHSI) camera can be used to capture and process images of brain tissue, using the wide spectrum of light between visible and infrared wavelengths. That additional information — beyond the human eye — has the potential to allow for more accurate and complete tumor removal.

“In the hands of a neurosurgeon, this camera, when combined with machine learning, could dramatically improve outcomes for some of our most vulnerable brain tumor patients,” said Richard Jaepyeong Cha, Ph.D., an optical engineer and principal investigator at the Sheikh Zayed Institute of Pediatric Surgical Innovation. “We are able to attach the camera to a surgical microscope and process a significant amount of information from the patient while in the operating room. Not only could this lead to more complete tumor resection, it will also allow the surgeon to save as much healthy brain tissue as possible and reduce lifelong neurological complications.”

Why we’re excited

Brain tumors are the most common solid tumors in children, accounting for the highest number of pediatric cancer deaths globally each year. To develop a treatment plan, neurosurgeons need to understand the tumor’s features, including its type, grade of malignancy, location and its categorization as a primary or metastatic cancer. This information leads to decisions about how to remove or biopsy a tumor.

Under the current protocols, surgeons evaluate tumor margins in the operating room by examining the appearance of the brain tissue and sending out small samples to the pathology department for biopsies. This can lead to longer surgeries and difficult real-time surgical decisions. For instance, some low-grade tumors are visually indistinguishable from healthy brain tissue.

In four investigational cases approved by the hospital’s institutional research board, the sHSI camera was used in the operating room to help segment healthy pediatric brain tissue from tumors. Unlike the conventional red-green-blue (RGB) imaging cameras, which use only those three colors, HSI captures spectral data at each pixel of the image — a task too complex for the human eye — and sends it instantly for processing by an algorithm designed to assist in tumor segmentation.

What’s ahead

Despite the small dataset, the researchers were able to successfully segment healthy brain tissue from lesions with a high specificity during pediatric brain tumor resection procedures. Significant work remains to refine the technology and the machine learning behind it. Researchers also plan to integrate the sHSI camera into a laparoscope to visualize tumors that are not on the brain’s surface and collect data from more angles.

“As we develop these groundbreaking tools, we plan to continue to expand the dataset and refine the algorithm to make pediatric neurosurgery continually more precise,” said Naomi Kifle, M.S., research and development engineer at Children’s National and first author on the paper. “As our dataset grows, we hope to create a model that can distinguish healthy brain tissue, tumor and skull. This groundbreaking surgical tool shows significant promise.”

doctors doing heart surgery

Novel dye may improve outcomes for liver surgery

Researchers at Children’s National Hospital and the National Cancer Institute (NCI) have developed a novel, near‐infrared dye that can help surgeons identify structures and detect leakage during liver surgery, offering a promising tool that may someday improve outcomes for patients undergoing gastroenterology procedures.

The problem has vexed the medical community for some time: Despite advances in bile leak detection, only a third of bile duct injuries are found at the time of surgery, extending hospital stays and increasing the risk of liver failure, sepsis and even death.

Why we’re excited

The new dye – known as Bile Label Dye 760 (BL-760) – provided several promising advantages over existing surgical tools during non-clinical testing. When administered into the liver, BL‐760 was excreted and visible in bile ducts within minutes, without significant or prolonged impact on organ tissue. Its fluorescence against the surgical field also provided a superior view of leaks, offering an opportunity to treat the patient while still in the operating room. Details were published recently in Lasers in Surgery and Medicine.

“BL-760 is a promising option for monitoring the health of the liver during surgery, and we are excited to continue our testing and hopefully see first-in-human trials in the future,” said Richard Cha, Ph.D., principal investigator at the Sheikh Zayed Institute of Pediatric Surgical Innovation, part of the NIH-funded team that developed the dye.

doctors doing heart surgery

The new dye – known as Bile Label Dye 760 (BL-760) – provided several promising advantages over existing surgical tools during non-clinical testing.

The big picture

The dye could significantly advance hepatobiliary and pancreatic (HPB) procedures in years to come. More than 40,000 new cases of liver cancer are diagnosed each year, causing more than 30,000 deaths in the U.S. alone. Gallbladder disease is also one of the most common conditions in the U.S., with more than 20 million people affected annually. In pediatrics, gall bladder removal, or cholecystectomy, is on the rise.

Procedures to treat these diseases have many challenges. During minimally invasive surgery, including laparoscopic cholecystectomy or robot-assisted hepatectomy, surgeons can struggle to precisely identify the bile ducts because of a narrow field of view or because they are embedded in fat or other tissues. Existing FDA-approved contrast agents that can enhance the biliary anatomy such as indocyanine green (ICG) aren’t well tailored for HPB surgeries because of the timing of their administration and their inferior ability to highlight biliary structures. In addition, while pre-operative imaging has improved outcomes, it cannot be used to predict leaks from the surgery itself.

What’s ahead

BL-760 was created at Children’s National and NCI by a team of experts in surgery and engineering, led by Anthony Sandler, M.D., senior vice president and surgeon-in-chief. They hope to continue their testing on the dye in the months ahead. The team was encouraged when Michele Saruwatari, M.D., a Joseph E. Robert Fellow in the Sheik Zayed Institute, recently won first place in the resident and fellow abstract presentation competition at the annual meeting of the Society of American Gastrointestinal and Endoscopic Surgeons.

“Having this tool in the operating room will change outcomes for our pediatric patients,” Sandler said.  “This dye has the potential to become an essential step in liver cancer surgery, cholecystectomy and treating other pediatric diseases like biliary atresia. I look forward to the day when we can get it in the hands of surgical teams.”

schematic of Mueller polarimetric imaging

Novel technique improved nerve visualization in head and neck surgery

In a pre-clinical model, researchers from Children’s National Hospital found that the Mueller polarimetric imaging, a novel technique that improves image contrast, may help identify nerves from other surrounding tissues during neck and head surgical procedures, avoiding accidental nerve damage.

“This technology holds great promise for the possibility of a truly noninvasive imaging approach and may help improve surgical outcomes by potentially reducing inadvertent, ill effects of nerve injuries in head and neck surgery,” said Bo Ning, Ph.D., R&D engineer at Children’s National and lead author of the study.

This pre-clinical study presents the first application of a full-field polarimetric imaging technique in vivo during head and neck surgery to highlight the vagus nerve (VN) and a branch that supplies all the intrinsic muscles to the larynx, known as recurrent laryngeal nerve (RLN).

“Unlike conventional nerve identification devices, this technique is noninvasive and less interruptive to intact tissues without disrupting surgical workflows,” said Ning et al. “Since the technique has an easy mechanism and promising performance in our study, this novel method holds great potential for real-time, noninvasive, and convenient nerve visualization.”

While some promising methods use polarimetric imaging for tissue characterizations, the current literature is still limited to ex vivo conditions due to the system complications and prolonged acquisition speeds.

“Recently, the industry released a new polarimetric camera, which is compact and allows fast and high-definition polarimetric imaging through simple snapshots. Enlightened by this technical advance, we have developed a practical polarimetric imaging method,” said Ning, who also develops compact and practical imaging systems for surgical innovation, including 3D, fluorescent, laser speckle and hyperspectral techniques. “It allows fast polarimetric analysis and can acquire birefringence maps over the whole field of view within 100 milliseconds, which provides an appropriate speed for directly surgical use.”

The new approach proofs that the concept is feasible to set up in live subjects during head and neck surgery, which can also be easily adapted for other surgeries. Among the seven subjects, the VNs and RLNs were successfully differentiated from arteries and other surrounding tissues.

Additional co-authors from Children’s National include Itai Katz, Ph.D., M.S., R&D staff engineer III; Anthony D. Sandler, M.D., Senior Vice President and Surgeon-in-Chief; Richard Jaepyeong Cha, Ph.D., research faculty assistant professor.

schematic of Mueller polarimetric imaging

Researchers at Children’s National used a novel technique that improves image contrast, which may help improve surgical outcomes.