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.
Department of Psychiatry, Yale University School of Medicine, CT.
M S
MS
Gandelman
R M
RM
Baldwin
S S
SS
Zoghbi
Y
Y
Zea-Ponce
R B
RB
Innis
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