Evaluation of ultrafiltration for the free-fraction determination of single photon emission computed tomography (SPECT) radiotracers: beta-CIT, IBF, and iomazenil.
An ultrafiltration system was evaluated for the free-fraction measurement of SPECT radiotracers (beta-CIT, IBF, and iomazenil) used in functional brain imaging. The effect of temperature, storage, centrifugal force, tracer concentration, and percentage filtered demonstrated a relative error of < 9%. As a result of the minimal temperature effect, 25 degrees C was employed for all measurements. A comparison of the ultrafiltration system with equilibrium dialysis revealed < 5% difference for beta-CIT and iomazenil, but 16% for IBF. Additionally, the time and ease of operation considerably favored the ultrafiltration system. The precision quantitated by repetition was < 6% for between-run and within-run variability. In conclusion, ultrafiltration provided rapid results, demonstrated minor analytical errors, revealed generally good correlation with equilibrium dialysis, and allowed excellent precision.
Gandelman
M S
MS
Department of Psychiatry, Yale University School of Medicine, CT.
Baldwin
R M
RM
Zoghbi
S S
SS
Zea-Ponce
Y
Y
Innis
R B
RB
D000327:Adsorption; D001572:Benzofurans / Q000032:analysis* / Q000097:blood / Q000493:pharmacokinetics; D001798:Blood Proteins / Q000378:metabolism; D003042:Cocaine / Q000031:analogs & derivatives* / Q000032:analysis / Q000097:blood / Q000493:pharmacokinetics; D003956:Dialysis; D005069:Evaluation Studies as Topic; D005442:Flumazenil / Q000031:analogs & derivatives* / Q000032:analysis / Q000097:blood / Q000493:pharmacokinetics; D006801:Humans; D007457:Iodine Radioisotopes; D008567:Membranes, Artificial; D011485:Protein Binding; D011759:Pyrrolidines / Q000032:analysis* / Q000097:blood / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D013696:Temperature; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D014462:Ultrafiltration / Q000379:methods
D001572:Benzofurans; D001798:Blood Proteins; D007457:Iodine Radioisotopes; D008567:Membranes, Artificial; D011759:Pyrrolidines; C062439:5-iodo-N-((1-ethyl-2-pyrrolidinyl)methyl)-2,3-dihydrobenzofurancarboxamide; D005442:Flumazenil; C069723:2beta-carbomethoxy-3beta-(4-iodophenyl)tropane; C063038:iomazenil; D003042:Cocaine