PT  - JOURNAL ARTICLE
AU  - D Mathews
AU  - B S Walker
AU  - B C Allen
AU  - H Batjer
AU  - P D Purdy
TI  - Diagnostic applications of simultaneously acquired dual-isotope single-photon emission CT scans.
DP  - 1994 Jan 01
TA  - American Journal of Neuroradiology
PG  - 63--71
VI  - 15
IP  - 1
4099  - http://www.ajnr.org/content/15/1/63.short
4100  - http://www.ajnr.org/content/15/1/63.full
SO  - Am. J. Neuroradiol.1994 Jan 01; 15
AB  - PURPOSE To report the development and validation of a technique of dual tracer single-photon emission CT brain imaging using technetium-99m hexamethylpropyleneamine oxime and iodine-123 iodoamphetamine agents and the application of this technique in patients with a variety of diagnoses. METHODS Contamination between the two isotopes' energy windows was calculated by opening both energy windows while scanning a group of patients using a single isotope. To compare uniformity of I-123 down-scatter, Tc-99m studies were performed both before and after the administration of I-123 in five of 24 dual studies. The 24 patients studied with the dual-isotope technique were evaluated during acetazolamide testing, trial balloon occlusion, or embolization of an arteriovenous malformation. RESULTS In a dual acquisition, average count contamination of an I-123 study by Tc-99m was less than 1% of the total I-123 counts, and contamination of a Tc-99m study by I-123 was approximately 12% of the total Tc-99m counts. Tc-99m studies performed both before and after the administration of I-123 demonstrated that contaminating counts do not adversely affect scan interpretation. Dual-tracer scans were completed in all 24 patients, 10 of whom showed changes after intervention. CONCLUSIONS Dual-tracer single-photon emission CT brain scans of adequate diagnostic quality are possible using Tc-99m and I-123.