Greenberg Radiology Institute of Highland Park, IL, installed the first Siemens ECAT 953 positron emission tomography system in the U.S. last year, according to executive director Benjamin F. Armbruster. The system was developed and produced by the German vendor's PET joint venture with CTI of Knoxville.
Armbruster, former marketing manager for Siemens' nuclear medicine business, left the imaging vendor to join the private radiology practice a year ago (SCAN 2/14/90).
GRI began scanning with the PET unit in December. The center does not have a cyclotron on site, choosing instead to purchase fluorine from an outside cyclotron and synthesize 18-fluorodeoxyglucose (FDG).
The high resolution of the Siemens system enables GRI to perform PET studies with injections of 5 mCi of FDG, instead of the standard dose of 10 mCi. The lower dose requirement helps the center scan more patients, using less FDG, Armbruster said.
GRI purchases 600 to 700 mCi of F-18 daily. Since the isotope has a half-life of 110 minutes, the volume of FDG available for scanning following synthesis is about 100 mCi. Six to eight patients a day can be easily scanned with this volume of FDG using 5 mCi per exam, he said.
The center has also developed an imaging routine that optimizes radioisotope use. Rather than performing transmission scans prior to each emission scan, all transmission scans are performed before the PET agent is available.
"Most sites do a transmission scan that takes 20 or 30 minutes. Then they inject and wait another 30 minutes. Then they do the emission scan. We bring all of our people in early and perform transmission scans up front, so that is all over with by the time the dose arrives," he said.
GRI should make a profit with the PET scanner--which cost over $2 million--if it scans six to eight patients a day for at least 250 days a year, Armbruster said.
The PET system has already expanded GRI's referral base. The radiology practice has received psychiatric patients for the first time and is increasing its cardiac imaging business now that it offers PET services, he said.
