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Lab Reports

Breath Analysis for Cystic Fibrosis

Jane Hill Breathprints
Image courtesy of Jane Hill.

By analyzing a patient’s exhaled breath, Thayer Professor Jane Hill hopes to develop a more efficient diagnostic tool with the potential to both extend and improve the lives of people suffering from cystic fibrosis. The Cystic Fibrosis Foundation has awarded Hill and her colleagues $1.2 million over the next three years to study more than 300 adult and pediatric patients at five clinical sites. According to Hill, each patient in the study will receive both the current gold standard test—culturing a sputum sample—and the breath test, in which a breath sample is analyzed using advanced chromatography and mass spectrometry. The team aims to identify and validate molecular biomarkers for a common respiratory infection, Pseudomonas aeruginosa, that is particularly dangerous for people with cystic fibrosis.

Cystic fibrosis patients often experience multiple simultaneous respiratory infections, but sputum might contain matter from only part of the lung, giving an incomplete diagnostic picture. In contrast, a patient’s breath offers evidence of all the infections at once. Calling breath “a window into the health of the entire lung,” Hill says that molecules in a breath sample act “like a fingerprint,” enabling the identification of specific infections almost immediately, whereas cultures can take days or even weeks.

Pseudomonas aeruginosa mutates really quickly. It figures out how to live in your lung environment and how to hide itself from your immune system and how to become more drug resistant fairly quickly. The sooner you can discover that it’s there and direct treatment toward its eradication, then the better your outcomes are as a patient.”

Hill hopes this research will result in a handheld device, similar to a breathalyzer, that could be used with a smartphone app to quickly diagnose certain respiratory conditions. “People already have handheld devices that probably could be modified, once you know what you’re looking for,” she says.

The three-year study, led by Hill and co-principal investigators from Arizona State University and Colorado Children’s Hospital, will include patients at five sites, including Dartmouth-Hitchcock.

—Kristen Senz

Imaging for Back Surgery

Professor Keith Paulsen, adjunct professors David Roberts, MD, and Songbai Ji, and colleagues have developed an intraoperative stereovision (iSV) system to make back surgery safer and less costly.

While MRIs and CT scans can pinpoint spine problems, such as compressed vertebrae or herniated disks, finding a clear surgical path to those problem areas is not always as straightforward since tissue and bone not only stand in the way, but can also move during spinal surgery. The iSV system, developed with colleagues from Geisel School of Medicine, the University of Vermont, and Worcester Polytechnic University, uses a complex algorithm and two cameras attached to a surgical microscope to produce real-time 3D images on a monitor to guide surgeons during procedures. This type of stereoscopic system has been used in brain surgery—technology pioneered by Roberts and the late Thayer Professor John Strohbehn—but has been unexplored for spinal surgery. Paulsen and a team at Dartmouth’s Center for Surgical Innovation tested the iSV system on porcine spines and is now converting the system into a handheld wand. Although use in humans may be several years away, Paulsen remains optimistic about the system’s potential impact. “By rendering images in real time with a simple handheld tool, we believe we can make surgeries safer and less costly in the future,” he says.

The system is detailed in the article, “Stereovision Co-Registration in Image-Guided Spinal Surgery: Accuracy Assessment Using Explanted Porcine Spines,” published in the journal Operative Neurosurgery.

—Callaway Zuccarello

Categories: The Great Hall, Lab Reports

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