Comparison of Ga-67 citrate images obtained with rectilinear scanner and large-field Anger camera

Two methods for Ga-67 citrate imaging were compared on 20 patients. Scans were performed using approximately equal procedure time with two instruments: (A) a dual 5-in. rectilinear scanner with medium-energy collimator, with a single window spanning both the 93-keV and the 185-keV spectral peaks; and (B) a large-field (15-in. diam) Anger camera equipped with moving table, medium-energy collimator, and three windows covering the 93-keV, 185-keV, and 300-keV peaks separately. Sixteen abnormal sites and 24 normal sites were selected for comparison. Each site was evaluated by four physicians experienced in interpreting Ga-67 citrate images. The observers performed significantly better using the images obtained with the large-field camera (three windows) than with the dual 5-in. scanner (single window).