[IEEE 1999 IEEE Nuclear Science Symposium. Conference Record. 1999 IEEE Nuclear Science Symposium and Medical Imaging Conference - Seattle, WA, USA (24-30 Oct. 1999)] 1999 IEEE Nuclear Science Symposium. Conference Record. 1999 Nuclear Science Symposium and Medical Imaging Conference (Cat. No.99CH37019) - Absolute quantitation of I-131 activity distributions using a high-resolution rotating collimator: a phantom study