RT Journal Article SR Electronic T1 A Comparison of Two Cerebral Perfusion Tracers, N-Isopropyl I-123 p-Iodoamphetamine and I-123 HIPDM, in the Human JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 25 OP 30 VO 25 IS 1 A1 B. Leonard Holman A1 Robert G. L. Lee A1 Thomas C. Hill A1 Richard D. Lovett A1 John Lister-James YR 1984 UL http://jnm.snmjournals.org/content/25/1/25.abstract AB Both N-isopropyl I-123 p-iodoamphetamine (IMP) and I-123 HIPDM have been advocated as radiotracers for assessing regional cerebral perfusion. We compared the biodistribution of the two tracers in 19 patients without evidence of neurological disease. Following intravenous injection, both tracers accumulated initially in the lung. Early after injection the fraction of the total brain uptake was higher for I-123 HIPDM than for I-123 IMP. The peak brain activity for I-123 IMP was higher than for I-123 HIPDM. Brain activity was unchanged with both tracers between 30 and 60 min after injection. Tomographic images were similar in appearance for both tracers. No eye uptake greater than background was observed with either tracer in any patient at 2, 24, and 48 hr. I-123 IMP is superior for tomographic imaging because of its higher brain uptake, whereas I-123 HIPDM may be superior for studies performed during rapid changes in blood flow.