Usefulness of Medium-Energy Collimator for Sentinel Node Lymphoscintigraphy Imaging in Breast Cancer Patients

This study was performed to investigate the usefulness of a general-purpose medium-energy (ME) collimator for the accu-rate localization of the sentinel lymph node (SLN) in breast cancer patients. Methods: We compared phantom images and lymphoscintigraphy images obtained under different conditions for a patient with breast cancer. Comparisons were performed between 2 cameras, between a low-energy high-resolution (LEHR) collimator and a general-purpose ME collimator, and be-tween energy windows centered at 141 keV and at 146 keV. Pro-file curves and image contrast were evaluated along with the visual interpretation of images. The most suitable imaging time was selected from the relationship between contrast and the data acquisition time. Results: The images obtained with the general-purpose ME collimator and the energy window centered at 141 keV were of poorer quality than those obtained with th