RT Journal Article SR Electronic T1 Delayed Positive Gastrointestinal Bleeding Studies with Technetium-99m-Red Blood Cells: Utility of a Second Injection JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 330 OP 332 VO 32 IS 2 A1 Jacobson, Arnold F. YR 1991 UL http://jnm.snmjournals.org/content/32/2/330.abstract AB