Graduate Student Presents at International Medical Physics Conference

Peter Halcrow, a graduate student in the biology department, presented his research on “Non-Contact (Air-Coupled) Ultrasound Applied to Cortical Bone Phantoms” at a special symposium on ultrasound technology during the annual meeting of the American Association of Physicists in Medicine (AAPM), which was held jointly with the annual meeting of the Canadian Organization of Medical Physicists (COMP) in Vancouver, BC on July 31.

An abstract of the work was published in AAPM’s journal, Medical Physics. Ganezer and Halcrow’s travel and accomodations for AAPM/COMP were made possible by a Department of Energy grant (3P031m105068) written by Leena Furtado, director of the Program for Excellence in Graduate Studies.

The only student who gave a presentation at the five-day conference, Halcrow says that to present and network alongside medical practitioners and researchers from institutions across the globe was a privilege.

“To give a talk at a conference of that magnitude… was an eye-opener,” says Halcrow. “It shows you that hard work pays off.”

Halcrow, who was preparing to take the MCAT (Medical College Admissions Test) after earning his bachelor’s degree in biochemistry at Biola University, decided to enroll in a physics course at California State University, Dominguez Hills. After the first class, he took the initiative to ask his professor, Dr. Kenneth Ganezer, if there were any research projects that he could join him in. The physicist is involved in several projects, including Super-K, an international particle physics project. Because of Halcrow’s interest in medicine, Ganezer suggested that he assist him with his research on non-contact bone imaging.

Halcrow, who conducted the research with Ganezer and Dr. John Bulman of Loyola Marymount University, says that their work is groundbreaking on several levels. While ultrasound has mainly been used for medical imaging of organs, using the technology as a method of analyzing bone has opened up possibilities for radiation-free imaging.

“Every time a patient is subjected to an X-ray or a CT scan, they’re being exposed to a certain amount of ionizing radiation, and radiation is harmful to the human body,” says Halcrow. “The ultrasound is non-ionizing, so it doesn’t expose patients to radiation.

“This particular study is innovative in the fact that it’s non-contact [ultrasound],” he continues. “With contact ultrasound, they use a coupling gel, as they do for fetal imaging. The gel is known to cause pneumonia and infections. Another aspect is the assessment of burn patients, which by using contact ultrasound would be very painful. Also, in the future non-contact ultrasound will most likely be used to examine the eyeball.”

Halcrow says that the ultimate goal of the research is to be able to detect and monitor osteoporosis.

“We’re getting good results with our bone analysis,” he says. “The main goal of this particular project we’re doing now is to assess bone status and fracture risk utilizing non-contact ultrasound.  Conventional contact ultrasound currently predicts fracture risk, but we’re developing [the idea that] non-contact ultrasound can predict fracture risk while eliminating the infectious coupling gels and systematic errors associated with the conventional contact method.”

Ganezer says that Halcrow put a lot of work into the abstract that he presented at AAPM/COMP conference, as well as the longer format paper that they are also submitting for publication in Medical Physics. He says that the opportunity that Dominguez Hills students have to present at academic conferences like AAPM/COMP alongside professionals and scholars is invaluable.

“It’s good for our students… to do presentations effectively as peers with professional scientists and to interact in the context of a research meeting to present new scientific results,” he says.

Ganezer also says that opportunities like these reflect well on the university among more research-oriented institutions.

“In our particular session, everybody had a Ph.D. and was from a Research I institution or a hospital with a research component,” he says. “[Students] get an opportunity to present their research. But they also get an opportunity to present material that has strong scientific impact as well as educational impact.”

Ganezer and Halcrow also presented “Neutron Fluxes at the patient plane and dosages measured at the Maze door with various openings for the Jaws and MLC” ) at the AAPM/COMP meeting, which discussed their findings on the flux (number per second) and energy spectrum of neutrons produced by x-rays and their interaction with the components of an Intensity Modulated Radiation Therapy (IMRT) system.

“Although the levels of neutrons were relatively low in our study and other similar studies,it is important to characterize and monitor the neutron levels, to prevent unnecessary concerns about neutron exposure and to help in finding better ways to shield IMRT patients from neutrons,”  says Ganezer.

Halcrow looks forward to entering medical school and becoming a surgeon after earning his master’s degree in biophysics at CSU Dominguez Hills. He currently teaches in the biology department, where he follows in his mother’s footsteps: Dr. Ruth Scott Halcrow was a professor in the Department of Health Sciences here at CSUDH from 1980 to 2000. The youngest child among five brothers and two sisters, Peter Halcrow is the only one of his siblings to pursue an advanced degree, and is enthusiastic at the prospect of a career where he will combine his passions for both research and healing.

“I’ve worked in the emergency room at Huntington Memorial Hospital in Pasadena, so I’ve been exposed to both worlds,” he says. “Medicine is my ultimate goal and I’m currently looking into M.D./Ph.D. programs. As a physician, I’d like to do research as well.”

“Research is usually underestimated,” Halcrow says. “It’s the scientists in the labs who are actually making a difference, spending hours, days, and months working really hard to advance science and health. Doctors take scientists’ discoveries and apply it to the medical field; I’d like to do both.”