Skip Navigation

Advanced Search

New GPS Technology Aids In Radiology Procedures

Made possible by grant from George Hoag Foundation

French Hospital Medical Center (FHMC) is now equipped with the IG4, a new “GPS” navigation system for needles and tools used in interventional radiology procedures including electrical, thermal or chemical tumor ablations, abscess drainages and suspicious mass lesion biopsies. The IG4 enhances FHMC’s ability to provide the highest quality patient care in diagnostic and treatment imaging. FHMC and Cedars-Sinai Medical Center in Los Angeles are the first hospitals on the entire West Coast, encompassing CA, OR, WA, AZ, NV, UT, to utilize this important new emerging medical technology. Funding for the new medical equipment was supported by a grant from the George Hoag Family Foundation.


This state-of-the-art technology is used by interventional radiologists as a needle based tool tracking system similar to GPS to navigate within organs such as the lungs, liver, the vascular system, the peritoneal cavity and kidneys during procedures using a roadmap CT scan. The device directs the tips of radiologist’s needles and a limited selection of guide wires in the body using a virtual CT scan map just as GPS is used in navigating on roads. IG4’s “four dimensional” (real time plus 3D) imaging capabilities even allow for the mapping of movement cycles such as heartbeat and respiration.

Information from a CT scan is loaded into the IG4 and three smalls pads are placed in a triangle on the patient’s body around the procedure area. The pads are used to sense movement of the body and of the needle and transmit information about position. Before the IG4, the radiologists would have to use dead reckoning piloting techniques and intermittent real time CT scanning each time a needle or tool was moved to confirm it was properly positioned. The IG4 only requires one scan, greatly reducing the patient’s radiation exposure while improving the accuracy and efficiency of the interventional radiology surgeon.

One of the advantages of having the IG4 is the creation of the real-time virtual map of the patient which displays the instrument position, orientation, and trajectory. These visuals provide a guide for physicians to maneuver areas of interest that may be small, close to sensitive tissue, vessels or organs or difficult to access and visualize.


“We use the IG4 when it provides benefits, which is actually in most image guided needle based procedure situations. The ease of use of the technology and its ability to increase our speed, accuracy and confidence in complex anatomical situations is a great benefit, and, we are extremely fortunate to have it,” said Jaywant Parmar M.D., Director of Interventional Radiology Services. “Along with improved accuracy and reduced surgical times comes less exposure to radiation. Previous to this technology a CT scan was needed before and after every needle manipulation. Now, a CT scan only needs to be performed one time and ultrasound or CT can be used for updated needle tip position confirmation which greatly reduces the patient and surgical team radiation exposure. It truly provides a win-win situation on many fronts when properly utilized. It just works and extends CT guidance into a new realm. It is an incremental improvement on older guidance technologies such as STEALTH which is very limited in its applications.”

The George Hoag Family Foundation is a Santa Monica-based private philanthropic organization established in 1940 by the late Grace and George Hoag Sr. The family’s foundation supports many charitable endeavors particularly health related causes. George and Grace Hoag Sr. were involved in the initial organization of the J.C. Penny store chain.

Bottom of Navigation

Legal & Privacy Notices


Payment Assistance

Contact Us

Hospital Accreditation

© 2015 Dignity Health

French Hospital Medical Center
1911 Johnson Avenue
San Luis Obispo, CA 93401
(805) 543-5353