TY - JOUR T1 - Determination of Glomerular Filtration Rate by Means of Newly Developed Plastic Scintillation Counter Both With and Without Dilution Procedures JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1484 LP - 1488 VL - 42 IS - 10 AU - Kazuo Itoh Y1 - 2001/10/01 UR - http://jnm.snmjournals.org/content/42/10/1484.abstract N2 - The double-well single-plastic scintillation counter (DW counter) has been developed to reduce the need for technical expertise in a plasma sample method after a single injection of radioactive marker. The DW counter serves the 2 functions of a standard well counter in well A and a dose calibrator in well B. The aim of this study was to assess the clinical feasibility of the counter for the estimation of glomerular filtration rate (GFR) with 99mTc-diethylenetriaminepentaacetic acid (DTPA). Methods: The study was performed on 25 patients with varying degrees of renal dysfunction. The GFR was estimated by a single-sample method after a single injection of 99mTc-DTPA. Total injected dose and plasma radioactivity were calculated following 2 methods: standard dilution with a single well (dilution method) and no dilution with 2 wells (direct method). Results: The GFR directly estimated by the DW counter correlated excellently with the GFR estimated by the dilution method (r = 0.998; root mean square error = 2.01 mL/min/1.73 m2). The 95% of differences (−0.3124 to 0.0423 percentage injected dose [%ID]/L/1.73 m2) in plasma concentration between the 2 comparative methods was <2 SDs. The direct method tended to give slightly higher readings of plasma concentration than did the dilution method (95% confidence interval = −0.0364 to −0.0904 %ID/L/1.73 m2). Conclusion: The DW counter can circumvent laborious dilution techniques and expertise required for quantifying the GFR in a single-sample method after a single injection of 99mTc-DTPA in clinical practice. It is proposed as an alternative to the standard dilution method. ER -