A new medical imager for detecting and guiding the biopsy of suspicious breast cancer lesions is capable of spotting tumors that are half the size of the smallest ones detected by standard imaging systems, according to a new study. The results of initial testing of the PEM/PET system, designed and constructed by scientists at the Department of Energy’s Thomas Jefferson National Accelerator Facility, West Virginia University School of Medicine and the University of Maryland School of Medicine will be published in the journal Physics in Medicine and Biology on Feb. 7.