Sm. Moerlein et al., FIRST-PASS EXTRACTION FRACTION OF I-123 LABELED PERFUSION TRACERS IN LIVING PRIMATE BRAIN, Nuclear medicine and biology, 21(6), 1994, pp. 847-855
The cerebral extraction and retention of three radioiodinated SPECT pe
rfusion tracers were measured using residue detection in a baboon. A p
ermeability-surface area product PS' with special relevance to SPECT w
as calculated from the retention of tracer in the brain after 10 min.
PS' differs from the traditional PS value, which is calculated from th
e tracer clearance curve at 2 min. The PS' values ranged from 50 to 95
mL/min/100 g, decreased in the order [I-123]IMP > [I-123]iodoperidol
approximate to [I-123]HIPDM and did not differ for specific activities
of 10 MBq/mmol to 74 TBq/mmol. These radioiodinated compounds exhibit
ed extraction characteristics superior to these of [Tc-99m]HMPAO but u
nderestimated cerebral blood flow when flows were above 20-30 mL/min/1
00 g, underscoring the need for development of a more ideal SPECT perf
usion tracer.